- A Pictet-Spengler ligation for protein chemical modification
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Aldehyde- and ketone-functionalized proteins are appealing substrates for the development of chemically modified biotherapeutics and protein-based materials. Their reactive carbonyl groups are typically conjugated with α-effect nucleophiles, such as substituted hydrazines and alkoxyamines, to generate hydrazones and oximes, respectively. However, the resulting C=N linkages are susceptible to hydrolysis under physiologically relevant conditions, which limits the utility of such conjugates in biological systems. Here we introduce a Pictet-Spengler ligation that is based on the classic Pictet- Spengler reaction of aldehydes and tryptamine nucleophiles. The ligation exploits the bioorthogonal reaction of aldehydes and alkoxyamines to form an intermediate oxyiminium ion; this intermediate undergoes intramolecular C-C bond formation with an indole nucleophile to form an oxacarboline product that is hydrolytically stable. We used the reaction for site-specific chemical modification of glyoxyl- and formylglycine-functionalized proteins, including an aldehyde-tagged variant of the therapeutic monoclonal antibody Herceptin. In conjunction with techniques for site-specific introduction of aldehydes into proteins, the Pictet-Spengler ligation offers a means to generate stable bioconjugates for medical and materials applications.
- Agarwal, Paresh,Van Der Weijden, Joep,Sletten, Ellen M.,Rabuka, David,Bertozzi, Carolyn R.
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Read Online
- N-(benzyloxy)-2-chloronicotinamide compound as well as preparation method and application thereof
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The invention belongs to the technical field of chemical synthesis and medicine application, and particularly relates to preparation and application of an N-(benzyloxy)-2-chloronicotinamide compound. The preparation method comprises the following steps: reacting phthalic anhydride with hydroxylamine, then reacting with triethylamine for acidification to prepare N-hydroxyphthalimide, then carrying out substitution and hydrazinolysis, and finally reacting with dichloronicotinoyl chloride to prepare the N-(benzyloxy)-2-chloronicotinamide compound. The preparation method disclosed by the invention is simple and convenient to operate, the structure of the obtained product is confirmed by a nuclear magnetic hydrogen spectrum, herbicidal activity tests are carried out on the obtained 15 target products, and results show that all target compounds have an obvious inhibition effect on the seeds of the Agrostis matsumurae under the concentration of 1mM, and the inhibition effect reaches 100%; and along with the decrease of the concentration, even if the concentration reaches 100 [mu] M, the target compound can still show good herbicidal activity.
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Paragraph 0016; 0037-0038
(2021/06/23)
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- Novel fluorinated 7-hydroxycoumarin derivatives containing an oxime ether moiety: Design, synthesis, crystal structure and biological evaluation
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A series of fluorinated 7-hydroxycoumarin derivatives containing an oxime ether moiety have been designed, synthesized and evaluated for their antifungal activity. All the target compounds were determined by1H-NMR,13C-NMR, FTIR and HR-MS spectra. The single-crystal structures of compounds 4e, 4h, 5h and 6c were further confirmed using X-ray diffraction. The antifungal activities against Botrytis cinerea (B. cinerea), Alternaria solani (A. solani), Gibberella zeae (G. zeae), Rhizoctorzia solani (R. solani), Colletotrichum orbiculare (C. orbiculare) and Alternaria alternata (A. alternata) were evaluated in vitro. The preliminary bioassays showed that some of the designed compounds displayed the promising antifungal activities against the above tested fungi. Strikingly, the target compounds 5f and 6h exhibited outstanding antifungal activity against B. cinerea at 100 μg/mL, with the corresponding inhibition rates reached 90.1 and 85.0%, which were better than the positive control Osthole (83.6%) and Azoxystrobin (46.5%). The compound 5f was identified as the promising fungicide candidate against B. cinerea with the EC50 values of 5.75 μg/mL, which was obviously better than Osthole (33.20 μg/mL) and Azoxystrobin (64.95 μg/mL). Meanwhile, the compound 5f showed remarkable antifungal activities against R. solani with the EC50 values of 28.96 μg/mL, which was better than Osthole (67.18 μg/mL) and equivalent to Azoxystrobin (21.34 μg/mL). The results provide a significant foundation for the search of novel fluorinated 7-hydroxycoumarin derivatives with good antifungal activity.
- Dai, Peng,Jiao, Jian,Wang, Qing-Qing,Zhang, Shu-Guang,Zhang, Wei-Hua
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- Oxime ether heterocyclic formamide derivatives and preparation method and application thereof
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The invention provides an oxime ether heterocyclic formamide derivative and a preparation method and application thereof, and particularly relates to the oxime ether heterocyclic formamide derivativeof which the chemical structural general formula is shown in a formula I. The invention discloses the structural general formula, a synthesis method and an application of the oxime ether heterocyclicformamide derivative serving as an insecticide, a bactericide and a plant virus resisting agent. The invention also discloses an application of the insecticidal composition in preventing and treatingagricultural, forestry and horticultural plant insect pests, diseases and virus diseases in combination with agriculturally acceptable auxiliaries or synergists and commercial insecticides, bactericides, plant virus resisting agents and acaricides, and a preparation method of the insecticidal composition in prevention and treatment of agricultural, forestry and horticultural plant insect pests, diseases and virus diseases.
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- Vinylogous Aza-Michael Addition of Urea Derivatives with p-Quinone Methides Followed by Oxidative Dearomative Cyclization: Approach to Spiroimidazolidinone Derivatives
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Herein, we report an efficient protocol for the synthesis of spiro-imidazolidinone-cyclohexadienones from p-quinone methides (p-QMs) and dialkyloxy ureas under mild conditions. The strategy follows a two-step process involving an initial vinylogous conjugate addition of urea derivatives to p-QMs, followed by oxidative dearomative cyclization of open-chain product to the projected spiro-imidazolidinones. This protocol exhibits good functional group tolerance and provides a straightforward method to access spiro-imidazolidinone-cyclohexadienones. In follow-up chemistry, we have shown the debenzylation of spiroimidazolidinones to give N-hydroxycyclic ureas. (Figure presented.).
- Kaur, Navpreet,Singh, Priyanka,Banerjee, Prabal
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p. 2813 - 2824
(2021/04/21)
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- Synthesis, Crystal Structure, Herbicidal Activity, and SAR Study of Novel N-(Arylmethoxy)-2-chloronicotinamides Derived from Nicotinic Acid
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Nicotinic acid, also known as niacin, is a natural product, which is widely found in plants and animals. To discover novel natural-product-based herbicides, a series of N-(arylmethoxy)-2-chloronicotinamides were designed and synthesized. Some of the new N-(arylmethoxy)-2-chloronicotinamides exhibited excellent herbicidal activity against Agrostis stolonifera (bentgrass) at 100 μM. Compound 5f (2-chloro-N-((3,4-dichlorobenzyl)oxy)nicotinamide) possessed excellent herbicidal activity against Lemna paucicostata (duckweed), with an IC50 value of 7.8 μM, whereas the commercial herbicides clomazone and propanil had values of 125 and 2 μM, respectively. The structure-activity relationships reported in this paper could be used for the development of new herbicides against monocotyledonous weeds.
- Yu, Chen-Sheng,Wang, Qiao,Bajsa-Hirschel, Joanna,Cantrell, Charles L.,Duke, Stephen O.,Liu, Xing-Hai
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p. 6423 - 6430
(2021/06/28)
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- Hydrogen-Bond Catalysis of Imine Exchange in Dynamic Covalent Systems
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The reversibility of imine bonds has been exploited to great effect in the field of dynamic covalent chemistry, with applications such as preparation of functional systems, dynamic materials, molecular machines, and covalent organic frameworks. However, acid catalysis is commonly needed for efficient equilibration of imine mixtures. Herein, it is demonstrated that hydrogen bond donors such as thioureas and squaramides can catalyze the equilibration of dynamic imine systems under unprecedentedly mild conditions. Catalysis occurs in a range of solvents and in the presence of many sensitive additives, showing moderate to good rate accelerations for both imine metathesis and transimination with amines, hydrazines, and hydroxylamines. Furthermore, the catalyst proved simple to immobilize, introducing both reusability and extended control of the equilibration process.
- Schaufelberger, Fredrik,Seigel, Karolina,Ramstr?m, Olof
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p. 15581 - 15588
(2020/10/02)
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- N-benzyloxy substituted symmetric oxamide compound and preparation method and application thereof
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The invention discloses an N-benzyloxy substituted symmetric oxamide compound and a preparation method and application thereof, the structural formula of the N-benzyloxy substituted symmetric oxamidecompound is shown as the formula (I): in the formula (I), the structures of two substituted benzene rings are the same, the number of substituents R on each substituted benzene ring is 1-2, and the substituent R is selected from H, halogen, C1-C4 alkyl or C1-C3 alkoxy. The N-benzyloxy substituted symmetric oxamide compound is a new compound with an efficient weeding effect, and provides a basis for research and development of a novel herbicide.
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Paragraph 0031; 0033-0034
(2020/12/30)
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- NOVEL ALKENYL AND BETA-SUBSTITUTED PHOSPHONATES AS ANTIMICROBIAL AGENTS
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The present disclosure relates to novel compounds, pharmaceutical compositions, and methods for treating or preventing microbial infection caused by parasites or bacteria, such as Plasmodium falciparum or related Plasmodium parasite species and Mycobacterium tuberculosis or related Mycobacterium bacteria species. The compounds are α,β-unsaturated analogs of fosmidomycin and can inhibit deoxyxylulose phosphate reductoisomerase (Dxr) in many microbes, such as P. falciparum.
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Paragraph 0191; 0156
(2019/01/17)
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- Catalytic asymmetric aza-Michael addition of fumaric monoacids with multifunctional thiourea/boronic acids
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The first chemical enantioselective synthesis of N-hydroxyaspartic acid derivatives using chiral multifunctional thiourea/boronic acid organocatalysts was developed. A series of fumaric monoacids underwent an intermolecular asymmetric aza-Michael addition of O-alkyl hydroxylamines in excellent regioselectivity. The addition of another carboxylic acid raised the enantiomeric enrichment up to 97% ee. O-Deprotection of the aza-Michael adduct provided an aspartate-derived hydroxylamine fragment applicable for KAHA (α-keto acid-hydroxylamine) ligation.
- Michigami, Kenichi,Murakami, Hiroki,Nakamura, Takeru,Hayama, Noboru,Takemoto, Yoshiji
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supporting information
p. 2331 - 2335
(2019/03/06)
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- Synthesis and photochemical studies of 2-nitrobenzyl-caged N-hydroxysulfonamides
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Recently, N-hydroxysulfonamides (RSO2NHOH) caged by photolabile protecting groups have attracted significant interest as potential photoactive nitroxyl (HNO) donors. The selectivity of the desired HNO generation pathway from photocaged N-hydroxysulfonamides versus a competing pathway involving O-N bond cleavage is dependent on the specific photodeprotection mechanism of the phototrigger. We present a new class of photocaged N-hydroxysulfonamides incorporating the well-established o-nitrobenzyl photoprotecting group, including a derivative incorporating an additional carbonate linker. Photodecomposition of o-NO2Bn-ON(H)SO2CF3 and the corresponding 2-nitro-4,5-dimethoxybenzyl analog generated the desired HNO and CF3SO2- as a minor pathway, with competing photoinduced O-N bond cleavage to release CF3SO2NH2 as the major photodecomposition pathway. Photolysis of the corresponding -SO2CH3 analogs resulted in O-N bond cleavage only. The presence of the o-nitro substituent was shown to be essential for photoactivity. Photorelease of the parent HNO donor CH3SO2NHOH was observed as the major product upon irradiation of o-NO2Bn-OC(O)ON(H)SO2CH3, with the desired HNO release and O-N bond cleavage occurring as minor pathways. Photoproduct quantum yields for each species have been determined by actinometry. The effect of solvent, pH and air on the mechanism of photodecomposition was studied for o-NO2Bn-ON(H)SO2CH3. The ratio of the solvents in the solvent mixture (CH3CN and phosphate buffer, pH 7.0), the pH of the aqueous component of the buffer, and the presence of oxygen did not affect the amount of each photoproduct and the observed rate constant for O-N bond cleavage. Possible mechanisms for the various pathways are proposed.
- Zhou, Yang,Bharadwaj, Vinay,Rahman, Mohammad S.,Sampson, Paul,Brasch, Nicola E.,Seed, Alexander J.
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- MEPicides: α,β-Unsaturated Fosmidomycin Analogues as DXR Inhibitors against Malaria
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Severe malaria due to Plasmodium falciparum remains a significant global health threat. DXR, the second enzyme in the MEP pathway, plays an important role to synthesize building blocks for isoprenoids. This enzyme is a promising drug target for malaria due to its essentiality as well as its absence in humans. In this study, we designed and synthesized a series of α,β-unsaturated analogues of fosmidomycin, a natural product that inhibits DXR in P. falciparum. All compounds were evaluated as inhibitors of P. falciparum. The most promising compound, 18a, displays on-target, potent inhibition against the growth of P. falciparum (IC50 = 13 nM) without significant inhibition of HepG2 cells (IC50 > 50 μM). 18a was also tested in a luciferase-based Plasmodium berghei mouse model of malaria and showed exceptional in vivo efficacy. Together, the data support MEPicide 18a as a novel, potent, and promising drug candidate for the treatment of malaria.
- Wang, Xu,Edwards, Rachel L.,Ball, Haley,Johnson, Claire,Haymond, Amanda,Girma, Misgina,Manikkam, Michelle,Brothers, Robert C.,McKay, Kyle T.,Arnett, Stacy D.,Osbourn, Damon M.,Alvarez, Sophie,Boshoff, Helena I.,Meyers, Marvin J.,Couch, Robin D.,Odom John, Audrey R.,Dowd, Cynthia S.
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supporting information
p. 8847 - 8858
(2018/10/05)
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- High activity N - oxyl new nicotine analogs and its preparation method and application (by machine translation)
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The invention belongs to the insecticide field, and in particular relates to high activity N - oxyl anabasine analogue and its preparation method and application. The invention by introducing the flexible side chain, has offered a kind of novel structure, pesticidal activity with the pyrrole insectforest quite, to the bee safely high activity N - oxyl new nicotine analogs insecticide. The insecticide solves the drug resistance of the Imidacloprid and toxic properties of the bees, can be advantageous protection of crops, horticultural plants, fruit and vegetables and the like, to prevent the emergence of the pest, increases its output, while at the same time for the activity and beneficial biological toxicity of the insecticide development explored a new path. (by machine translation)
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- Transformation of masked benzyl alcohols to: O -aminobenzaldehydes through C-H activation: A facile approach to quinazolines
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Direct transformation of a directing group to important synthetic units would provide a high atom efficiency synthetic approach in synthetic chemistry. Herein, a convenient protocol for the synthesis of o-aminobenzaldehyde and benzoxazole derivatives from benzyl alcohols has been developed by employing (N,N-dimethyl)oxamoyl amide as a directing group in a palladium-catalyzed intramolecular amination. Furthermore, the attached directing center may not only be transformed into the product, but may also be further applied to generate synthetically important quinazoline and quinoline units. Finally, a high atom efficiency one-pot, two-step approach to form quinazolines from benzyl alcohol derivatives has been achieved in good yields, thus demonstrating its high utility.
- Chen, Xiaolan,Han, Jian,Zhu, Yan,Yuan, Chunchen,Zhang, Jingyu,Zhao, Yingsheng
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supporting information
p. 10241 - 10244
(2016/10/22)
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- Effect of Substituents and Stability of Transient Aluminum-Aminals in the Presence of Nucleophiles
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Disubstituted hydroxylamines are synthesized and used to form aluminum-amide complexes. These reagents mask carbonyl groups in situ via nucleophilic addition. The stability and utility of the aluminum-aminals are presented in the context of selectively controlling nucleophilic addition on substrates with multiple carbonyl groups.
- Barrios, Francis J.,Springer, Brannon C.,Hazlitt, Robert A.,Colby, David A.
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p. 175 - 180
(2015/05/05)
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- NBu4NI-catalyzed intermolecular C-O cross-coupling reactions: Synthesis of alkyloxyamines
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A practical and simple nBu4NI-catalyzed C-O bond formation for the synthesis of alkyloxyamines was achieved under metal-free conditions. The reaction is applicable to the coupling of a range of benzylic and allylic hydrocarbons with N-hydroxyphthalimide and is tolerant of various functional groups. The reaction mechanism was primarily investigated and a radical process was proposed.
- Lv, Yunhe,Sun, Kai,Wang, Tingting,Li, Gang,Pu, Weiya,Chai, Nannan,Shen, Huihui,Wu, Yingtao
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p. 72142 - 72145
(2015/09/08)
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- Aminolysis of an N-diazeniumdiolated amidine as an approach to diazeniumdiolated ammonia
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Recent theoretical studies have suggested that the parent diazeniumdiolate ion, H2N-N(O)=NO- ( diazeniumdiolated ammonia ), might be stable enough to be isolated and that it could potentially serve as a uniquely advantageous prodrug form of bioactive nitroxyl (HNO). Here, we report on an attempt to isolate its O2-benzylated derivative by aminolysis of the C=N bond in PhC(NH2)=N-N(O)=NOBn. The reaction proved remarkably sluggish in comparison to aminolysis of unsubstituted benzamidine, and the desired product could not be isolated, apparently because of base sensitivity of the NH2 group. Consistent with this interpretation, O-benzylhydroxylamine and N2O were recovered from the reaction mixture in high yields, along with N,N′-dibutylbenzamidine. Theoretical calculations rationalize the observed slow aminolysis by demonstrating that the diazeniumdiolate group greatly suppresses the electrophilicity of the adjacent C=N carbon center, rendering attack at that position endothermic. The data provide significant insights into the challenges inherent to the pursuit of diazeniumdiolated ammonia.
- Biswas, Debanjan,Hrabie, Joseph A.,Saavedra, Joseph E.,Cao, Zhao,Keefer, Larry K.,Ivanic, Joseph,Holland, Ryan J.
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p. 4512 - 4516
(2014/06/09)
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- Expanding insight into asymmetric palladium-catalyzed allylic alkylation of N-heterocyclic molecules and cyclic ketones
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Eeny, meeny, miny.?? enaminones! Lactams and imides have been shown to consistently provide enantioselectivities substantially higher than other substrate classes previously investigated in the palladium-catalyzed asymmetric decarboxylative allylic alkylation. Several new substrates have been designed to probe the contributions of electronic, steric, and stereoelectronic factors that distinguish the lactam/imide series as superior alkylation substrates (see scheme). These studies culminated in marked improvements on carbocyclic allylic alkylation substrates. Copyright
- Bennett, Nathan B.,Duquette, Douglas C.,Kim, Jimin,Liu, Wen-Bo,Marziale, Alexander N.,Behenna, Douglas C.,Virgil, Scott C.,Stoltz, Brian M.
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supporting information
p. 4414 - 4418
(2013/04/23)
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- Synthesis, in vitro antimycobacterial and antibacterial evaluation of IMB-070593 derivatives containing a substituted benzyloxime moiety
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A series of novel IMB-070593 derivatives containing a substituted benzyloxime moiety and displaying a remarkable improvement in lipophilicity were synthesized and evaluated for their in vitro antimycobacterial and antibacterial activity. Our results reveal that the target compounds 19a-m have considerable Gram-positive activity (MIC: 0.008-32 μg/mL), although they are generally less active than the reference drugs against the Gram-negative strains. In particular, compounds 19h, 19j, 19k and 19m show good activity (MICs: 0.008-4 μg/mL) against all of the tested Gram-positive strains, including ciprofloxacin (CPFX)- and/or levofloxacin (LVFX)-resistant MSSA, MRSA and MSSE. Moreover, compound 19l (MIC: 0.125 μg/mL) is found to be 2-4 fold more active than the parent IMB070593, CPFX and LVFX against M. tuberculosis H37Rv ATCC 27294.
- Wei, Zengquan,Wang, Jian,Liu, Mingliang,Li, Sujie,Sun, Lanying,Guo, Huiyuan,Wang, Bin,Lu, Yu
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p. 3872 - 3893
(2013/06/05)
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- HETEROCYCLIC OXIME COMPOUNDS
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The invention relates to compounds of formula (I) and salts thereof wherein the substituents are as defined in the specification; a compound of formula (I) for use in the treatment of the human or animal body, in particular with regard to c-Met tyrosine kinase mediated diseases or conditions; the use of a compound of formula (I) for manufacturing a medicament for the treatment of such diseases; pharmaceutical compositions comprising a compound of the formula (I), optionally in the presence of a combination partner, and processes for the preparation of a compound of formula (I).
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Page/Page column 63
(2011/04/13)
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- Synthesis and antiprotozoal activity of n -alkoxy analogues of the trypanocidal lead compound 4,4′-bis(imidazolinylamino)diphenylamine with improved human blood-brain barrier permeability
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To improve the blood-brain barrier permeability of the trypanocidal lead compound 4,4′-bis(imidazolinylamino)diphenylamine (1), five N-alkoxy analogues were synthesized from bis(4-isothiocyanatophenyl)amine and N-alkoxy-N-(2-aminoethyl)-2-nitrobenzenesulfonamides following successive chemical reactions in just one reactor (one-pot procedure). This involved: (a) formation of a thiourea intermediate, (b) removal of the amine protecting groups, and (c) intramolecular cyclization. The blood-brain barrier permeability of the compounds determined in vitro by transport assays through the hCMEC/D3 human cell line, a well-known and characterized human cellular blood-brain barrier model, showed that the N-hydroxy analogue 16 had enhanced blood-brain barrier permeability compared with the unsubstituted lead compound. Moreover, this compound displayed low micromolar IC50 against Trypanosoma brucei rhodesiense and Plasmodium falciparum and moderate activity by intraperitoneal administration in the STIB900 murine model of acute sleeping sickness.
- Nieto, Lidia,Mascaraque, Ainhoa,Miller, Florence,Glacial, Fabienne,Ríos Martínez, Carlos,Kaiser, Marcel,Brun, Reto,Dardonville, Christophe
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experimental part
p. 485 - 494
(2011/04/15)
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- Alkoxyamine-cyanoborane adducts: Efficient cyanoborane transfer agents
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We report the synthesis of the hitherto unknown zwitterionic alkoxyamino cyanoboranes by reduction of O-alkyloximes with sodium cyanoborohydride; unprecedented cyanoboronated N-alkoxyformamidines were also isolated as by-products. Boronated alkoxyamines were found to be efficient cyanoborane transfer agents towards more basic amines, including aminosugars; they were also successfully transformed into neoglycoconjugates by the neoglycorandomization reaction with reducing sugars.
- Marquez, Jose M.,Martinez-Castro, Elisa,Gabrielli, Serena,Lopez, Oscar,Maya, Ines,Angulo, Manuel,Alvarez, Eleuterio,Fernandez-Bolanos, Jose G.
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supporting information; experimental part
p. 5617 - 5619
(2011/06/26)
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- O-Substituted N-oxy arylsulfinamides and sulfonamides in Michael reactions
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O-Substituted N-oxy arylsulfinamides and sulfonamides undergo fast aza-Michael reaction in the presence of base and electron-deficient α,β-unsaturated olefins under mild conditions. With N-silyloxy benzenesulfinamides, no aza-Michael product is observed and a hetero aza-Brook type rearrangement takes place induced by the base. Room temperature N-desulfinylation of N-benzyloxybenzenesulfinamide is achieved using BF 3.Et2O. N-Alkoxy arylsulfonamides aza-Michael adducts are found to be generally highly stable under strongly acidic and basic conditions.
- Bonifacio, Vasco D. B.,Kumar, Rakesh P.,Prabhakar, Sundaresan,Lobo, Ana M.
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experimental part
p. 266 - 276
(2011/11/06)
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- Design, synthesis and antifungal activities of novel pyrrole alkaloid analogs
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A series of novel analogs of pyrrole alkaloid were designed and synthesized by a facile method and their structures were characterized by 1H NMR, 13C NMR and high-resolution mass spectrometry (HRMS). The structure of compound 2a was identified by 2D NMR including heteronuclear multiple-quantum coherence (HMQC), heteronuclear multiple-bond correlation (HMBC) and H-H correlation spectrometry (H-H COSY) spectra. Their antifungal activities against five fungi were evaluated, and the results indicated that some of the title compounds showed moderate fungicidal activities in vitro against Alternaria solani, Cercospora arachidicola, Fusarium omysporum, Gibberella zeae and Physalospora piricola at the dosage of 50 μg mL -1. Compound 2a and 3a exhibited good activities against P. piricola at low dosage.
- Wang, Ming-Zhong,Xu, Han,Liu, Tuan-Wei,Feng, Qi,Yu, Shu-Jing,Wang, Su-Hua,Li, Zheng-Ming
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experimental part
p. 1463 - 1472
(2011/05/04)
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- NOVEL HETEROCYCLIC NITROGENOUS COMPOUNDS, THEIR PREPARATION AND THEIR USE AS ANTIBACTERIAL MEDICAMENTS
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The invention relates to nitrogenous heterocyclic compounds of formula in which: R1 represents hydrogen, ?(CH2)m?NH2, ?(CH2)m?NH(C1-C6)alk, ?(CH2)m?N(C1-C6)alk2, ?(CH2)m?NH?C(NH)NH2 or ?(CH2)m?NH?CH-NH, m is equal to 1 or 2; R2 and R3 together form a nitrogenous heterocycle of aromatic character with 5 vertices containing 1, 2 or 3 nitrogen atoms, substituted on a nitrogen atom by R4; R4 represents hydrogen, C1-C6)alk or a chain of formula: -(A)n-(NH)o?(CH2)p?(CHR')qR'' A represents C-O, C-NH or SO2; R' represents hydrogen or carboxy.
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Page/Page column 16
(2010/04/30)
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- 2-[(arylmethoxy)imino]imidazolidines with potential biological activities
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A series of 2-[(arylmethoxy)imino]imidazolidines was synthesized by reacting 2-chloro-4,5-dihydroimidazole with corresponding O- arylmethylhydroxylamines and evaluated for their α1-, α2-adrenergic and imidazoline I1, I2 receptor binding affinities. The most potent 2-[(naphthalen-1-ylmethoxy)imino] imidazolidine showed a high selectivity and good affinity for the [ 3H]prazosin-labeled α1-adrenoceptors (Ki = 107 nM). Representative compounds of this series were also tested in vivo for possible circulatory effects in rats after intravenous administration.
- Saczewski, Jaroslaw,Hudson, Alan L.,Rybczynska, Apolonia
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experimental part
p. 671 - 680
(2010/07/04)
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- Synthesis and fungicidal activity of macrolactams and macrolactones with an oxime ether side chain
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Three series of novel macrolactams and macrolactones - 12-alkoxyimino- tetradecanlactam, 12-alkoxyiminopentadecanlactam, and 12-alkoxyiminodecanlactone derivatives (7A, 7B, and 7C) - were synthesized from corresponding 12-oxomacrolactams and 12-oxomacrolactone. Their structures were confirmed by 1H NMR and elemental analysis. The Z and E isomers of 7A and 7B were separated, and their configurations were determined by 1H NMR. These compounds showed fair to excellent fungicidal activities against Rhizoctonia solani Kuehn. It is interesting that the Z and E isomers of most of the compounds have quite different fungicidal activities. The fact that the compounds have a gradual increase of fungicidal activity in the order of 7A, 7C, and 7B indicated that the macrocyclic derivatives with a hydrogen-bonding acceptor (=N-O-) and a hydrogen-bonding donor (-CONH-) on the ring, and a three methylenes distance (CH2CH2CH2) between these two functional groups, exhibited the best fungicidal activity. The bioassay also showed that 7B not only has good fungicidal activity but also may have a broad spectrum of fungicidal activities.
- Huang, Jia-Xing,Jia, Yue-Mei,Liang, Xiao-Mei,Zhu, Wei-Juan,Zhang, Jian-Jun,Dong, Yan-Hong,Yuan, Hui-Zu,Qi, Shu-Hua,Wu, Jin-Ping,Chen, Fu-Heng,Wang, Dao-Quan
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experimental part
p. 10857 - 10863
(2009/11/30)
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- HYDROXAMIC ACID DERIVATIVE AND AGE GENERATION INHIBITOR CONTAINING THE DERIVATIVE
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To provide a novel compound which inhibits the generation of AGE and an AGE generation inhibitor containing the compound. A compound represented by the following formula or a pharmaceutically acceptable salt thereof, a medicinal composition containing the compound or such a salt thereof, and an additive composition containing the compound.
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Page/Page column 67
(2010/11/24)
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- Scandium(III) catalysis of transimination reactions. Independent and constitutionally coupled reversible processes
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Sc(OTf)3 efficiently catalyzes the self-sufficient transimination reaction between various types of C=N bonds in organic solvents, with turnover frequencies up to 3600 h-1 and rate accelerations up to 6 × 105. The mechanism of the crossover reaction in mixtures of amines and imines is studied, comparing parallel individual reactions with coupled equilibria. The intrinsic kinetic parameters for isolated reactions cannot simply be added up when several components are mixed, and the behavior of the system agrees with the presence of a unique mediator that constitutes the core of a network of competing reactions. In mixed systems, every single amine or imine competes for the same central hub, in accordance with their binding affinity for the catalyst metal ion center. More generally, the study extends the basic principles of constitutional dynamic chemistry to interconnected chemical transformations and provides a step toward dynamic systems of increasing complexity.
- Giuseppone, Nicolas,Schmitt, Jean-Louis,Schwartz, Evan,Lehn, Jean-Marie
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p. 5528 - 5539
(2007/10/03)
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- A solid-phase approach to DDB derivatives
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Since the discovery of 2,2′-dimethoxycarbonyl-4,4-dimethoxy-5,6, 5′,6′-biomethylenedioxy-biphenyl (DDB) as a potent anti-HBV agent, we have studied the structure-activity relationships of 4,4′-dimethoxy-5, 6,5′,6′-dimethenedioxy-2-alkyloxycarbonyl-2′-(4-substituted benzyl piperazin-1-yl)carbonyl-biphenyl as anti-HBV agents. Therefore, it is rational to extend this study to the 3,3′-disustituted-4,4′- dimethoxy-5,6,5′,6′-dimethenedioxy-2-alkyloxycarbonyl-2′- Serine derivatives. Thus, in an attempt to develop an efficient method for the preparation of a large number of DDB derivatives, the reaction between a DDB acid chloride and serine derivatives on solid support was studied. The structure of resulted compounds was confirmed by LC-MS and 1H NMR analysis. Compounds 2a, 2d, 2f, 2j showed in vitro anti-HBV activity without significant toxicity up to 100 μM.
- Qi, Xiuxiang,Wang, Xiaolai,Wang, Limin,Wang, Qiang,Cheng, Senxiang,Suo, Jishuan,Chang, Junbiao
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p. 805 - 810
(2007/10/03)
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- Stereoselective cyclization reactions of IBX-generated alkoxyamidyl radicals
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In this paper, a method for the generation of alkoxyamidyl radicals is presented. These N-centered radicals can efficiently be formed starting from the corresponding acylated alkoxyamines using IBX as an oxidant. Stereoselective 5-exo and 6-exo reactions with these N-heteroatom-centered radicals leading to isoxazolidines and [1,2]oxazinanes are discussed. The N-O bond in the heterocycles can readily be cleaved with SmI2 to provide N-acylated 1,3-amino alcohols.
- Janza, Birgit,Studer, Armido
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p. 6991 - 6994
(2007/10/03)
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- 1-Benzyloxy-4,5-dihydro-1H-imidazol-2-yl-amines, a novel class of NR1/2B subtype selective NMDA receptor antagonists
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Screening of the Roche compound depository led to the identification of (1-benzyloxy-4,5-dihydro-1H-imidazol-2-yl)-butyl amine 4, a structurally novel NR1/2B subtype selective NMDA receptor antagonist. The structure-activity relationships developed in this series resulted in the discovery of a novel class of potent and selective NMDA receptor blockers displaying activity in vivo.
- Alanine, Alexander,Bourson, Anne,Buettelmann, Bernd,Gill, Ramanjit,Heitz, Marie-Paule,Mutel, Vincent,Pinard, Emmanuel,Trube, Gerhard,Wyler, Rene
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p. 3155 - 3159
(2007/10/03)
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- Novel bifunctional chelating compounds containing hydroxamic acid residues
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New types of hydroxamic acid-based bifunctional chelators are provided. These chelators are designed to chelate metal ions that can be detected either by their paramagnetic or radioactive properties. Conjugation with peptides or protein can be achieved by the presence of a linker moiety in the molecular structure of these chelators.
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- Capture-ROMP-release: application for the synthesis of O-alkylhydroxylamines.
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[reaction: see text] A new capture-ROMP-release method for chromatography-free purification of N-hydroxysuccinimde Mitsunobu reactions is described. The Mitsunobu reaction captures a variety of alcohols onto a norbornenyl N-hydroxysuccinimide monomer. Subjection of the resulting crude reaction mixture to ROM-polymerization generates a polymer that can be precipitated with methanol and filtered from the Mitsunobu byproducts. Treatment of the polymer with hydrazine releases the substrate from the water-soluble polymer, producing a variety of O-alkylhydroxylamines with good purity.
- Harned, Andrew M,Hanson, Paul R
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p. 1007 - 1010
(2007/10/03)
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- Self-assembling heteropolymetallic chelates as imaging agents and radiopharmaceuticals
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Metal complexes of new ligands of the formula STR1 are useful as agents for medical imaging, particularly MRI, for in vitro or in vivo diagnostic or as radiopharmaceuticals. In these compounds, X--R1 --Y is a coordinating group able to form a highly stable complex with metal ions. Suitable units are for example derivatives of ortho-phenanthroline or of an hydroxamic acid. R2 and R3 are reactive functions such as amines or carboxylic groups. R4 and R5 are ligands, for instance diethylenetriaminepentaacetic acid 1,4,7,10-tetraacetic acid (DTPA), 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) or 1,4,8,11-tetraazacyclotetradecane-N, N', N", N'"-tetraacetic acid (TETA), of a different type than the X--R1 --Y units and able to strongly encapsulate metal ions with which the X--R1 --Y moieties form less stable chelates. Stable high molecular weight multimetallic entities are spontaneously formed by these ligands that spontaneously associate around metal ions through the X--R1 --Y units. Higher relaxivities thus are achieved. Mixed-complexes containing two different radionuclides are also obtained thus allowing imaging and therapy with one single chelate.
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- Nodulisporic acid derivatives
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The present invention relates to novel nodulosporic acid derivatives, which are acaricidal, antiparasitic, insecticidal and anthelmintic agents.
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- Herbicidally active phenylsubstituted 5-and 6-membered heterocyclic compounds
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A compound of formula (I): STR1 where E is oxygen or sulphur; A is CR3 or N where R3 is hydrogen or hydrocarbyl; D completes a 5 or 6-membered non-aromatic heterocyclic ring which optionally contains additional heteroatoms selected from oxygen, nitrogen or sulphur and which is optionally substituted by an optionally substituted lower hydrocarbyl group, or an optionally substituted heteroaryl group; R1 and R2 are each independently hydrogen; optionally substituted lower hydrocarbyl, or optionally substituted heteroaryl, or R1 and R2 together with the nitrogen atom to which they are attached, form a heterocyclic ring; Z represents halogen optionally substituted lower hydrocarbyl, optionally substituted lower hydocarbyloxy, optionally substituted lower hydrocarbylthio, hydrocarbylsulphinyl or hydrocarbylsulphonyl, cyano, nitro, CHO, NHOH, ONR7' R7", SF5 ; CO (optionally substituted lower hydrocarbyl), acylamino, COOR7, SO2 NR8 R9, CONR10 R11, OR12 or NR13 R14 where R7, R7', R7", R8, R9, R10 and R11 are independently hydrogen or lower hydrocarbyl; R12 is hydrogen; SO2 lower hydrocarbyl or COR15 ; R13 and R14 are independently lower hydrocarbyl, lower hydrocarbyloxy or a group R12 ; R15 is OR16, NR17 R18, hydrogen or lower hydrocarbyl; R16 is lower hydrocarbyl; R17 and R18 are independently hydrogen or lower hydrocarbyl; provided that when there are two or more substituents Z, they may be the same or different; and m is 0 or an integer from 1 to 5.
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- Flavin chemical models for monoamine oxidase inactivation by cyclopropylamines, α-silylamines, and hydrazines
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Models for the inactivation of the monoamine oxidase A and B, two closely related flavoenzymes, by cyclopropylamines, α-silylamines, and hydrazines have been investigated in order to gain insight into the possible chemical mechanisms for these processes. The activated (i.e. high reduction potential and electrophilicity) flavin, 3-methyl-5-ethyllumiflavinium perchlorate (5), was employed in this effort along with trans-2-phenylcyclopropylamine (1), a host of monosubstituted hydrazines (13-16), and α-(trimethylsilyl)benzylamine (9). Admixture of 5 with 1 (25°C, MeCN) results in instantaneous formation of the stable and completely characterized flavin-amine adducts 6 (K(e) = 2 x 104) derived by addition of the amine function in 1 to the 4a-position of 5. Reaction of the 4a-adduct 6 with cyclopropylamine 1 (85°C, MeCN) cleanly (80%) produces the aldimine 7 formed by condensation of the initial product, trans-cinnamaldehyde and amine 5. These results demonstrate that 4a-adducts related to 6 are capable of undergoing cyclopropane ring opening reactions by polar pathways to produce electrophilic α,β-unsaturated carbonyl products. Consequently, ring opening reactions proposed for monoamne oxidase inactivation by primary and perhaps secondary cyclopropylamines can occur by polar routes and, thus, are not uniquely attributable to radical mechanistic pathways. In a similar manner, the flavinium salt 5 undergoes rapid reaction with the α-silylamine 9 to produce a stable 4a-adduct 10 (K(e) = 7 x 104). Reaction of this adduct with 9 (45°C, MeCN) leads to initial production of N-[(α-trimethylsilyl)benzyl]benzaldimine (12) which undergoes desilylation to produce N-benzylbenzaldimine (11) under these conditions. Also, 4a-adduct 10 is rapidly converted to aldilne 11 by reaction with TBAF at 25°C in MeCN. These results show that 4a-adducts, generated from activated flavins and α-silylamines, participate in fragmentation processes leading to silylation of nucleophiles and production of carbonyl products. This polar mechanistic pathway models the known inactivation reactions of the MAOs by α-silylamines previously attributed to SET (radical) routes. Reaction of flavinium salt 5 with phenyl- or benzylhydrazine results in formation of 4a-phenyl or -benzyl flavin adducts. For example, admixture of 5 and PhNHNH2 in CH3CN at 25°C provides the characterizable 4a-phenyl and 4a-cyanomethyl flavins, 21 (28%) and 22 (55%), and benzene. Benzylhydrazine reacts similarly with 5 to produce only the 4a-benzyl adduct 23 (89%). Information about the mechanism for adduct formation in these reactions has come from studies with the hydrazine analogs, NH2NHCO2CH2Ph (15) and NH2OCH2Ph (16). These substances react rapidly with 5 in MeCN at 25°C to cleanly produce stable 4a-hydrazine adducts, 17. The results suggest that 4a-alkylation or -arylation reactions of the activated flavin 5 with hydrazines probably occur via the intermediacy of 4a-hydrazine flavin adducts related to 17. Thus, a polar mechanistic model is also consistent with the known inactivation reactions of the MAOs with hydrazines which are also reported to generate 4a-flavin alkylated and arylated MAO derivatives.
- Kim, Jong-Man,Hoegy, Susan E.,Mariano, Patrick S.
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p. 100 - 105
(2007/10/02)
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- Pyrylium-Mediated Synthesis of N-(Benzyloxy)pyridinium Salts
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Pyrylium salts 3 react with (benzyloxy)amines 2 generated by hydrazinolysis from their N-(benzyloxy)phthalimides to afford in moderate (35-65percent) yields the corresponding title salts 4.The 13C- and 1H-NMR spectra of the latter compounds are reported. Key Words: Pyridinium salts / Pyrylium salts
- Balaban, Teodor, Silviu,Tamasan, Juliana,Deleanu, Calin
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p. 173 - 176
(2007/10/02)
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- Synthesis, Regioselective Deprotonation, and Stereoselective Alkylation of Fluoro Ketimines
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Fluoroacetone imines of cyclohexylamine, valinol O-methyl ether, and phenylalaninol O-methyl ether and 2-fluorocyclohexanone imines of cyclohexylamine and phenylalaninol O-methyl ether were prepared.The temperature-dependent, regioselective deprotonation of these imines was employed in highly regioselective alkylation reactions.The deprotonation of fluoroacetone cyclohexylimine on the carbon bearing fluorine yielded only a single stereoisomer as determined by low temperature 19F NMR.In contrast, deprotonation of fluoroacetone O-benzyloximes was not regiospecific under any of the conditions examined.
- Welch, John T.,Seper, Karl W.
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p. 2991 - 2999
(2007/10/02)
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- Hydroxamic acids
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This invention provides a series of novel hydroxamic acids of formula I which are useful as inhibitors of metalloproteases such as endopeptidases.
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- Hydroxamic acids
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The invention provides a series of novel hydroxamic acids of the formula I which are useful as inhibitors of metalloproteases such as endopeptidases and wherein R1 is a hydrophobic group, R2 and R3 are each an amino acid residue, n is 1 or 2, and A is a group of the formula:-, -CHR4.CO.NH2, in which R4 is an amino acid residue. Also described are processes for the manufacture of the hydroxamic acids, pharmaceutically acceptable salts derived from the said acids and pharmaceutical compositions containing a said acid or salt.
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- Factors Affecting the Stability and Equilibria of Free Radicals. XIII. N-Alkoxy- and N-Aralkoxypicrylamines and ESR Spectra of the Corresponding Capto-Dative Persistent Aminyls
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Five O-alkylhydroxylamines and three aralkylhydroxylamines have been picrylated to give O-alkyl-N-picrylhydroxylamines.These were converted to the corresponding N-(ar)alkoxy-picryl-aminyl radicals in toluene solution, and the ESR spectra were recorded.Simulations of the spectra with reasonable parameters and g values confirm the expected radical structures.Hyperfine coupling constants for nuclei in the picryl (acceptor) ring are smaller than those for the (ar)alkoxy group.This indication of competitive electron pair delocalization to the picryl ring, together with the long lifetimes of these radicals (compared with the symmetrically substituted diphenylaminyls), both support the concept of captodative stabilization.
- Stanciuc, Gabriela,Caproiu, M. Teodor,Caragheorgheopol, Agneta,Caldararu, Horia,Balaban, Alexandru T.,Walter, Robert I.
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- Deuterium Isotope Effects and the Bunnet w Factor in Elimination Reactions of 4-Alkoxyimino-5,6-dihydro-6-alkoxyaminopyrimidin-2(1H)-one in Strong Acid Media
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Rate coefficients for the elimination of hydroxylamines from 4-alkoxyimino-5,6-dihydro-6-alkoxyaminopyrimidin-2(1H)-ones (1a) show maxima at H0 values of -1.8 (for O-benzylhydroxylamine) and -0.8 (for hydroxylamine) in a variety of mineral acids.The hitherto unknown values of H0 for trifluoromethanesulphonic acid are reported and this acid also gives a rate maximum at -1.8 for the elimination of O-benzylhydroxylamine from (1a; R2 = Bz).Bunnett w values for these eliminations fall in the range 6.0-16.0 (dependent upon the acid) implying that water is involved as a proton transfer agent.In contrast, eliminations in formic acid show low and variable w values and formate ion is involved as the proton transfer agent which explains the lack of a rate maximum in this acid.Deuterium isotope effects reveal a highly stereoselective elimination and support the proposal of an E1cB (irreversible) mechanism.The inhibition of elimination by the 5-fluoro-substituent is probably due to destabilisation of the intermediate carbanion by the lone pair electrons on fluorine.
- Atkins, Paul J.,Palling, David J.,Poon, Nai L.,Hall, C. Dennis
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p. 1107 - 1112
(2007/10/02)
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- ALKYLATION OF AMINOHYDROXY ANION, DISSOCIATED SPECIES OF HYDROXYLAMINE
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Aminohydroxy anion (3), dissociated species of hydroxylamine, was demontrated to be nucleophilic on oxygen atom from INDO calculation, and to give directly O-alkylhydroxylamines.
- Kashima, Choji,Yoshiwara, Nobutoshi,Omote, Yoshimori
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p. 2955 - 2956
(2007/10/02)
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