- Nickel-promoted oxidative domino Csp3-H/N-H bond double-isocyanide insertion reaction to construct pyrrolin-2-ones
-
The first nickel-catalyzed oxidative domino Csp3-H/N-H double isocyanide insertion reaction of acetamides with isocyanides has been developed for the synthesis of pyrrolin-2-one derivatives. A wide range of acetamides bearing various functional groups are compatible with this reaction system by utilizing Ni(acac)2as a catalyst. In this transformation, isocyanide could serve as a C1 connector and insert into the inactive Csp3-H bond, representing an effective way to construct heterocycles.
- Wen, Li-Rong,Wang, Ning-Ning,Du, Wu-Bo,Ma, Qiang,Zhang, Lin-Bao,Li, Ming
-
supporting information
p. 2895 - 2900
(2021/04/14)
-
- HFIP-mediated strategy towards β-oxo amides and subsequent Friedel-Craft type cyclization to 2?quinolinones using recyclable catalyst
-
A simple and cost-effective 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP)-mediated protocol for the synthesis of β-oxo amides has been described by using amines and β-keto esters as substrates. The reaction conditions were found to be highly efficient towards the cleavage of C[sbnd]O bond and consequent formation of the products in excellent yields and selectivity. The obtained β-oxo amides were further transformed in to the synthetically useful 2?quinolinones via intramolecular Friedel-Craft type cyclization of aromatic ring using ferrites as a recyclable catalyst. A spectrum of substrates bearing broad range of functional groups were well tolerated under the reaction conditions. The proposed mechanistic pathways were substantially verified by literature and mass-spectroscopic evidences.
- Kabi, Arup K.,Gujjarappa, Raghuram,Vodnala, Nagaraju,Kaldhi, Dhananjaya,Tyagi, Ujjawal,Mukherjee, Kalisadhan,Malakar, Chandi C.
-
supporting information
(2020/10/20)
-
- 2- Amino -3,4-dihydropyran -3- formamide analogue as well as preparation method and application thereof
-
The invention relates to a preparation method 2 - of a compound containing, amino - 333384-dihydropyran - 3 3, which comprises the following step :1) of linking diketene with R. 2 NH2 The reaction is stirred in a solvent to complete. ;2) Is added R. 3 NH2 , R1 CHO And a of Compound, and adding elemental iodine to reaction solution to complete curing, and drying the filter cake to obtain compound 2 - containing. amino - 3333,4-dihydropyran - 3 3-carboxamide compound, according to the present invention as well as its use. without isolation of intermediate, in a simple.
- -
-
Paragraph 0058-0078
(2020/03/25)
-
- 5-Aminothiophene-2,4-dicarboxamide analogues as hepatitis B virus capsid assembly effectors
-
Chronic hepatitis B virus (HBV) infection represents a major health threat. Current FDA-approved drugs do not cure HBV. Targeting HBV core protein (Cp) provides an attractive approach toward HBV inhibition and possibly infection cure. We have previously identified and characterized a 5-amino-3-methylthiophene-2,4-dicarboxamide (ATDC) compound as a structurally novel hit for capsid assembly effectors (CAEs). We report herein hit validation through studies on absorption, distribution, metabolism and excretion (ADME) properties and pharmacokinetics (PK), and hit optimization via analogue synthesis aiming to probe the structure-activity relationship (SAR) and structure-property relationship (SPR). In the end, these medicinal chemistry efforts led to the identification of multiple analogues strongly binding to Cp, potently inhibiting HBV replication in nanomolar range without cytotoxicity, and exhibiting good oral bioavailability (F). Two of our analogues, 19o (EC50 = 0.11 μM, CC50 > 100 μM, F = 25%) and 19k (EC50 = 0.31 μM, CC50 > 100 μM, F = 46%), displayed overall lead profiles superior to reported CAEs 7–10 used in our studies.
- Tang, Jing,Huber, Andrew D.,Pineda, Dallas L.,Boschert, Kelsey N.,Wolf, Jennifer J.,Kankanala, Jayakanth,Xie, Jiashu,Sarafianos, Stefan G.,Wang, Zhengqiang
-
supporting information
p. 179 - 192
(2019/01/04)
-
- Synthesis of α-Alkyl-β-Hydroxy Amides through Biocatalytic Dynamic Kinetic Resolution Employing Alcohol Dehydrogenases
-
Chiral (α-substituted) β-hydroxy amides are interesting derivatives as they are useful building blocks of many biologically active compounds. Herein, the biocatalytic stereocontrolled synthesis of various acyclic syn-α-alkyl-β-hydroxy amides through a dynamic kinetic resolution is shown. Hence, a series of overexpressed alcohol dehydrogenases (ADHs) in Escherichia coli was used to reduce the corresponding racemic β-keto amides. Among them, ADH-A from Rhodococcus ruber and commercial evo-1.1.200 afforded the best activities and selectivities, giving access to the opposite enantiomers with high diastereomeric excess and excellent enantiomeric excess. Some of these compounds were obtained at semipreparative scale. (Figure presented.).
- Méndez-Sánchez, Daniel,Mourelle-Insua, ángela,Gotor-Fernández, Vicente,Lavandera, Iván
-
supporting information
p. 2706 - 2712
(2019/05/10)
-
- Substituted heteroaryl compounds and compositions and uses thereof
-
The invention provides a substituted heteroaryl compound and a composition thereof, and applications of the compound and the composition. The compound is a compound as shown in a formula I, or stereoisomer, tautomer, oxynitride, solvate, metabolite, pharmaceutically-acceptable salt or prodrug of the compound as shown in the formula I. The invention also provides a pharmaceutical composition containing the above-mentioned compound; and the above-mentioned compound and the pharmaceutical composition are capable of adjusting the activity of JAK kinases and are applied in prevention, treatment, therapy and alleviation of JAK kinase mediated diseases or disorders.
- -
-
Paragraph 0470; 0471; 0472; 0473
(2017/12/27)
-
- Design, synthesis and antiproliferative activities evaluation of thiazolopyrimidines derivatives through biginelli reaction
-
Background: Thiazolopyrimidines possessed their structural diversity and various biological activity. Up to date, thiazolopyrimidines derivatives have widespread applications in pharmaceutical fields. In this article, a series of thiazolopyrimidine derivatives were designed based on the lead compound structure in our previous studies. Methods: All the target compounds were synthesized with the coupling reaction, Biginelli reaction and “one-pot” aldol condensation. Their structures were identified by1H NMR,13C NMR spectra and HRMS. Antitumor activities of the target compounds were evaluated by MTT. Results: 25 new target compounds were synthesized and they primarily screened through testing their inhibitory rates against two human tumor cell lines and Compounds 15, 17, 20, 22, 40 exhibited more than 70% inhibitory rate against both MDA-MB-231 and K562. Further assessing their IC50 against five tumor cell lines, 15 and 22 show advantage over lead compound I in MDA-MB-231, K562 and PC-3. Conclusion: A series of thiazolopyrimidine derivatives were synthesized and the preliminary biological evaluation suggest that target compound 22 exhibited better antiproliferative activity against K562 than gossypol.
- Zhu, Pengju,Fu, Huansheng,Fang, Hao
-
p. 1382 - 1390
(2017/12/28)
-
- CYCLIC DIARYLBORON DERIVATIVES AS NLRP3 INFLAMMASOME INHIBITORS
-
Inhibitor compounds are disclosed. The compounds are effective in the treatment of diseases or conditions in which interleukin 1 β activity is implicated. Methods of synthesis of the compounds, as well as pharmaceutical compositions comprising the compounds are also disclosed.
- -
-
Paragraph 00176
(2017/02/24)
-
- SUBSTITUTED HETEROARYL COMPOUNDS AND METHODS OF USE
-
The present invention provides novel heteroaryl compounds, pharmaceutical acceptable salts and formulations thereof useful in preventing, treating or lessening the severity of a JAK-mediated disease. The invention also provides pharmaceutically acceptable compositions comprising such compounds and methods of using the compositions in the treatment of JAK-mediated disease.
- -
-
Paragraph 0330
(2016/12/22)
-
- SUBSTITUTED HETEROARYL COMPOUNDS AND METHODS OF USE
-
The present invention provides new heteroaryl compounds, pharmaceutical acceptable salts and formulations thereof useful in preventing, treating or lessening the severity of JAK-mediated diseases. The invention also provides pharmaceutically acceptable compositions comprising such compounds and methods of using the compositions in the treatment of JAK-mediated diseases.
- -
-
Paragraph 325
(2015/07/07)
-
- Vinylogous urethane vitrimers
-
Vitrimers are a new class of polymeric materials with very attractive properties, since they can be reworked to any shape while being at the same time permanently cross-linked. As an alternative to the use of transesterification chemistry, we explore catalyst-free transamination of vinylogous urethanes as an exchange reaction for vitrimers. First, a kinetic study on model compounds reveals the occurrence of transamination of vinylogous urethanes in a good temperature window without side reactions. Next, poly(vinylogous urethane) networks with a storage modulus of ≈2.4 GPa and a glass transition temperature above 80 °C are prepared by bulk polymerization of cyclohexane dimethanol bisacetoacetate, m-xylylene diamine, and tris(2-aminoethyl)amine. The vitrimer nature of these networks is examined by solubility, stress-relaxation, and creep experiments. Relaxation times as short as 85 s at 170 °C are observed without making use of any catalyst. In addition, the networks are recyclable up to four times by consecutive grinding/compression molding cycles without significant mechanical or chemical degradation. Catalyst-free vitrimers based on the transamination of vinylogous urethanes are prepared from readily accessible chemicals. These high Tg, cross-linked materials exhibit excellent mechanical properties, while the exchangeable bonds enable full stress-relaxation on short time scales and recycling over many cycles.
- Denissen, Wim,Winne, Johan M.,Du Prez, Filip E.,Rivero, Guadalupe,Nicola, Renaud,Leibler, Ludwik
-
p. 2451 - 2457
(2015/09/08)
-
- Facile eco-friendly synthesis of novel chromeno[4,3-b]pyridine-2,5-diones and evaluation of their antimicrobial and antioxidant properties
-
Rapid and facileaccess to novel chromeno[4,3-b]pyridine-2,5-dione derivatives was achieved by a mild base catalysed reaction of 4-chloro-3-formylcoumarin and acetoacetamides in PEG-300 as recyclable solvent. The compounds were evaluated for their antimicrobial activities against 3 Gram-positive and 3 Gram-negative bacteria (Staphylococcus epidermis, Vibrio parahaemolyticus, Bacillus subtilis, Escherichia coli, Staphylococcus aureus and Klebsiella pneumonia) with Cefotaxime control. They were further subjected to antioxidant studies using DPPH test with ascorbic acid control. While compounds 5d and 5k showed promising broad spectrum antibacterial properties against all the evaluated bacteria, compound 5g exhibited good antioxidant properties. Indian Academy of Sciences.
- Jaggavarapu, Satyanarayana Reddy,Kamalakaran, Anand Solomon,Jalli, Ventkata Prasad,Gangisetty, Sravan Kumar,Ganesh, Munusswamy Ramanujam,Gaddamanugu, Gopikrishna
-
p. 187 - 195
(2014/04/03)
-
- Facile eco-friendly synthesis of novel chromeno[4,3-b]pyridine-2,5-diones and evaluation of their antimicrobial and antioxidant properties
-
Rapid and facile access to novel chromeno[4,3-b]pyridine-2,5-dione derivatives was achieved by a mild base catalysed reaction of 4-chloro-3-formylcoumarin and acetoacetamides in PEG-300 as recyclable solvent. The compounds were evaluated for their antimicrobial activities against 3 Gram-positive and 3 Gram-negative bacteria (Staphylococcus epidermis, Vibrio parahaemolyticus, Bacillus subtilis, Escherichia coli, Staphylococcus aureus and Klebsiella pneumonia) with Cefotaxime control. They were further subjected to antioxidant studies using DPPH test with ascorbic acid control. While compounds 5d and 5k showed promising broad spectrum antibacterial properties against all the evaluated bacteria, compound 5g exhibited good antioxidant properties. [Figure not available: see fulltext.]
- Jaggavarapu, Satyanarayana Reddy,Kamalakaran, Anand Solomon,Jalli, Ventkata Prasad,Gangisetty, Sravan Kumar,Ganesh, Munusswamy Ramanujam,Gaddamanugu, Gopikrishna
-
p. 187 - 195
(2016/02/26)
-
- A chemoselective route to β-enamino esters and thioesters
-
Conditions were developed for syntheses of β-enamino esters, thioesters, and amides. These reactions involve hydroxybenzotriazole derivatives in buffered media. Illustrative syntheses of some heterocyclic systems are given, including some related to protein-protein interface mimics.
- Xin, Dongyue,Burgess, Kevin
-
p. 2108 - 2110
(2014/05/06)
-
- Organocatalytic enantio- and diastereoselective conjugate addition to nitroolefins: When ketoamides surpass ketoesters
-
Our findings on the bifunctional squaramide-catalyzed enantioselective conjugate addition of ketoamides to nitroolefins are disclosed. It appears that simple acyclic methylene ketoamides, unlike the extensively studied ketoesters, afford the products in excellent diastereoselectivities, and maintain high yields and enantioselectivities. Moreover, competition and kinetic studies were conducted to rationalize the observed reactivity and selectivity. The high level of diastereocontrol, along with the amenability of the amide group to postfunctionalization, dramatically increase the synthetic usefulness of the transformation.
- Du, Haiying,Rodriguez, Jean,Bugaut, Xavier,Constantieux, Thierry
-
supporting information
p. 8458 - 8466
(2014/07/08)
-
- Catalyst-free rapid synthesis of benzo[4,5]imidazo[1,2-a]-pyrimidine-3- carboxamides via four-component coupling in one pot
-
Abstract: A new class of fused tricyclic benzo[4,5]imidazo[1,2-a]- pyrimidine-3-carboxamide derivatives was synthesized via an environmentally benign one pot sequential four-component condensation reaction of an amine, 2,2,6-trimethyl-4H-1,3-dioxin-4-one, an aldehyde and 1H-benzo[d]imidazol-2-amine without using catalyst in good yields.
- Shaabani, Ahmad,Seyyedhamzeh, Mozhdeh,Ganji, Nasim,Ng, Seik Weng
-
p. 481 - 487
(2014/04/03)
-
- A new copper-based metal-organic framework as a promising heterogeneous catalyst for chemo- and regio-selective enamination of β-ketoesters
-
Assembly of 5-nitro-1,2,3-benzenetricarboxylic acid (H3nbta) with CuII in the presence of 1,3-bis(1,2,4-triazol-1-yl)propane (1,3-btp) leads to a new metal-organic framework, [Cu(Hnbta)(1,3-btp)] ·2H2O (A1), which is shown to be an efficient and recyclable heterogeneous catalyst for enamination of β-ketoesters with excellent product yields and selectivity.
- Zhao, Ying,Deng, Dong-Sheng,Ma, Lu-Fang,Ji, Bao-Ming,Wang, Li-Ya
-
supporting information
p. 10299 - 10301
(2013/10/22)
-
- Four-component tandem reaction to synthesize dihydrotetrazolopyrimidinyl carbamides
-
Four-component tandem procedure to prepare a series of dihydrotetrazolopyrimidinyl carbamides starting from diketene, amine, 5-aminotetrazole, and aldehyde was newly developed in the presence of iodine. Most of the products were obtained in moderate to good yield after simple workup of the final reaction mixture, the scope and limitation was also probed into..
- Zeng, Li-Yan,Ji, Fei,Cai, Chun
-
experimental part
p. 237 - 241
(2012/04/17)
-
- Facile Biginelli-type reactions catalysed by super acidic ionic liquid under solvent-free conditions
-
[MeC(OH)2]+ClO4-?as a super acidic ionic liquid is an extremely active catalyst for Biginelli-type reactions. The present method is especially effective for the inactive aliphatic aldehydes. The solvent-free conditions, high catalytic activity, wide substrates tolerance and convenient product isolation make the protocol more advantageous.
- Wang, Liang,Zhou, Min,Chen, Qun,He, Ming-Yang
-
p. 712 - 714
(2013/02/23)
-
- Expedient synthesis of a 72-membered isoxazolino-β-ketoamide library by a 2·3-component reaction
-
An efficient 2·3-component reaction (2·3CR; a 2-component reaction followed, in one pot, by a3-component reaction) is presented for the synthesis of isoxazolino-β-ketoamides. This 2·3CR proceeds by (i) a Meldrum's acid-generated acyl ketene, which is trapped by an amine to form a β-ketoamide intermediate in a 2CR followed, in one pot, by (ii) a Mannich reaction followed by elimination of dimethyl amine·HCl to generate an α,β-unsaturated β-ketoamide dipolarophile that reacts in a nitrile oxide 1,3-dipolar cycloaddition reaction. This one-pot 2·3CR process delivers the targeted isoxazolino-β-ketoamide product. A total of 72 compounds are presented, all of which have been submitted to the NIH Molecular Libraries Small Molecule Repository for high-throughput biological screening.
- Knapp, John M.,Zhu, Jie S.,Wood, Alex B.,Kurth, Mark J.
-
scheme or table
p. 85 - 88
(2012/04/10)
-
- Studies on log Po/w of quinoxaline di-N-oxides: A comparison of RP-HPLC experimental and predictive approaches
-
As reported in our previous papers, a series of quinoxaline-2-carboxamide 1,4-di-N-oxide derivatives were synthesized and studied as anti-tuberculosis agents. Here, the capability of the shake-flask method was studied and the retention time (expressed as log K) of 20 compounds were determined by RP-HPLC analysis. We found that the prediction of log P by the RP-HPLC analysis can result in a high accuracy and can replace the shake-flask method avoiding the experimental problems presented by quinoxaline di-N-oxides. The studied compounds were subjected to the ALOGPS module with the aim of comparing experimental log Po/w values and predicted data. Moreover, a preliminary in silico screening of the QSAR relationship was made confirming the influence of reduction peak potential, lipophilicity, H-bond donor capacity and molecular dimension descriptors on anti-tuberculosis activity.
- Moreno, Elsa,Gabano, Elisabetta,Torres, Enrique,Platts, James A.,Ravera, Mauro,Aldana, Ignacio,Monge, Antonio,Perez-Silanes, Silvia
-
scheme or table
p. 7893 - 7908
(2011/11/05)
-
- New 3-methylquinoxaline-2-carboxamide 1,4-di-N-oxide derivatives as anti-Mycobacterium tuberculosis agents
-
Mycobacterium tuberculosis (M.Tb) is a bacillus capable of causing a chronic and fatal condition in humans known as tuberculosis (TB). It is estimated that there are 8 million new cases of TB per year and 3.1 million infected people die annually. Thirty-six new amide quinoxaline 1,4-di-N-oxide derivatives have been synthesized and evaluated as potential anti-tubercular agents, obtaining biological values similar to the reference compound, Rifampin (RIF).
- Ancizu, Saioa,Moreno, Elsa,Solano, Beatriz,Villar, Raquel,Burguete, Asunción,Torres, Enrique,Pérez-Silanes, Silvia,Aldana, Ignacio,Monge, Antonio
-
experimental part
p. 2713 - 2719
(2010/06/14)
-
- Diketene as an alternative substrate for a new Biginelli-like multicomponent reaction: one-pot synthesis of 5-carboxamide substituted 3,4-dihydropyrimidine-2(1H)ones
-
5-Carboxamide substituted 3,4-dihydropyrimidine-2(1H)one derivatives were synthesized in a simple and efficient method from the one-pot four-component reactions of an aliphatic or aromatic amine, diketene, an aromatic aldehyde and urea or thiourea in the presence of p-toluenesulfonic acid as a catalyst under mild reaction conditions at ambient temperature.
- Shaabani, Ahmad,Seyyedhamzeh, Mozhdeh,Maleki, Ali,Hajishaabanha, Fatemeh
-
experimental part
p. 4040 - 4042
(2010/07/06)
-
- Ca(CF3COO)2: An efficient Lewis acid catalyst for chemo- and regio-selective enamination of β-dicarbonyl compounds
-
A relevant procedure has been developed for the synthesis of β-enaminoesters catalysed by Ca(CF3COO)2. The reaction of β-ketoesters with primary amines was efficiently carried out under solvent-free conditions at room temperature and led to chemo- and regio-selective formations of enamine derivatives in high yields.
- Harrad, Mohamed Anoir,Outtouch, Rachid,Ait Ali, Mustapha,Firdoussi, Larbi El,Karim, Abdallah,Roucoux, Alain
-
scheme or table
p. 442 - 446
(2010/11/21)
-
- Mild and high-yielding synthesis of β-keto esters and β-ketoamides
-
In the presence of sodium acetate, the reaction between 2,2,6-trimethyl-4H-1,3-dioxin-4-one and secondary or tertiary alcohols (including chiral ones) or primary or secondary amines could be carried out in refluxing tetrahydrofuran, under much milder conditions than those described in the literature. In these new conditions, side products normally observed using the traditional protocol were avoided, and-keto esters and-ketoamides were normally obtained in quantitative yields.
- Sridharan, Vellaisamy,Ruiz, Miriam,Menendez, J. Carlos
-
experimental part
p. 1053 - 1057
(2010/06/16)
-
- Synthesis and antibacterial activities of novel oxazolidinones having spiro[2,4]heptane moieties
-
The synthesis of a new series of oxazolidinones having spiro[2,4]heptane moieties is described. Their in vitro antibacterial activities against both Gram-positive and Gram-negative bacteria were tested and the effect of substituents on the oxazolidinone ring was investigated. A particular compound Ih having fluoro group showed the most potent antibacterial activity.
- Kim, So-Young,Park, Hyeong Beom,Cho, Jung-Hyuck,Yoo, Kyung Ho,Oh, Chang-Hyun
-
scheme or table
p. 2558 - 2561
(2010/03/03)
-
- Dihydropyrazolopyrimidine Inhibitors of KV1.5 (IKur)
-
A series of dihydropyrazolopyrimidine inhibitors of KV1.5 (IKur) have been identified. The synthesis, structure-activity relationships and selectivity against several other ion channels are described.
- Vaccaro, Wayne,Huynh, Tram,Lloyd, John,Atwal, Karnail,Finlay, Heather J.,Levesque, Paul,Conder, Mary Lee,Jenkins-West, Tonya,Shi, Hong,Sun, Lucy
-
experimental part
p. 6381 - 6385
(2009/09/06)
-
- Synthesis and In-Vitro Activity of Novel 1β-Methylcarbapenems Having Spiro[2,4]heptane Moieties
-
The synthesis of a new series of 1β-methylcarbapenems having spiro[2,4]heptane moieties is described. Their in-vitro antibacterial activities against both gram-positive and gram-negative bacteria were tested and the effect of substituents on the pyrrolidine ring was investigated. Most compounds were shown to be more active than the compared meropenem and imipenem against Escherichia coli. One particular compound, IIIb, having hydroxy a moiety showed the most potent antibacterial activity.
- Park, Hyeong Beom,Jo, Nam Hyun,Hong, Joon Hee,Chei, Jung Hoon,Cho, Jung-Hyuck,Yoo, Kyung Ho,Oh, Chang-Hyun
-
p. 530 - 537
(2008/12/21)
-
- Microwave-assisted solution-phase synthesis of 1,4,5-trisubstituted pyrazoles
-
A small parallel library of 1,4,5-trisubstituted pyrazoles was prepared in solution using a three-step procedure starting from Meldrum acid. The Meldrum acid was acylated with different acyl chlorides and the products opened with different alcohols and amines to give substituted β-keto esters and β-keto amines. Further reaction with N,N-dimethylformamide dimethylacetal and the final cyclisation were effectively carried out under microwave irradiation. Scavenger resins were employed exclusively in the first step, whereas use of microwaves allowed complete conversion of the starting materials in the other two steps. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Giacomelli, Giampaolo,Porcheddu, Andrea,Salaris, Margherita,Taddei, Maurizio
-
p. 537 - 541
(2007/10/03)
-
- Method for preparing chiral diphosphines
-
The invention concerns a method for preparing a compound of formula (1) wherein: A represents naphthyl or phenyl optionally substituted; and Ar1, Ar2independently represent a saturated or aromatic carbocyclic group, optionally substituted.
- -
-
-
- An efficient and rapid synthesis of β-carboxamide derivatives using 2,2-dimethyl-2H,4H-1,3-dioxin-4-ones by microwave irradiation
-
A general, efficient and rapid method for the synthesis of various β-carboxamide derivatives using microwave irradiation is described. Excellent isolated yields were obtained in very short reaction times when conventional heating was replaced by microwave irradiation.
- Miriyala, Bruhaspathy,Williamson, John S.
-
p. 7957 - 7959
(2007/10/03)
-
- New transformations from a 3-silyloxy 2-aza-1,3-diene: Consecutive Zr- mediated retro-Brook rearrangement and reactions with electrophiles
-
A one-pot procedure for the transformation of the title compound to α- functionalized (silylated) and α,β-unsaturated secondary amides was described. The following steps were involved: a Zr-mediated retro-Brook rearrangement, selective deprotonation with n-BuLi on the organometallic intermediate, and trapping with electrophiles including alkyl and acyl halides and aldehydes. The electrophilic addition step occurred at a stabilized α-silyl carbanion center without affecting the near transition metal residue. In the case of aldehydes, the Peterson alkenation reaction took place on the transition metal complex in a highly stereoselective way. (C) 2000 Elsevier Science Ltd.
- Gandon, Vincent,Bertus, Philippe,Szymoniak, Jan
-
p. 4467 - 4472
(2007/10/03)
-
- Asymmetric hydrogenation method of a ketonic compound and derivative
-
The present invention relates to a process for the asymmetric hydrogenation of a ketonic compound and derivative. The invention relates to the use of optically active metal complexes as catalysts for the asymmetric hydrogenation of a ketonic compound and derivative. The process for the asymmetric hydrogenation of a ketonic compound and derivative is characterized in that the asymmetric hydrogenation of said compound is carried out in the presence of an effective amount of a metal complex comprising as ligand an optically active diphosphine corresponding to one of the following formulae: STR1
- -
-
-
- Syntheses of 5-(alkylaminocarbonyl)-4,6-dimethyl-2-pyridones from N- alkyl-3-oxobutanamides
-
1-Alkyl-5-(alkylaminocarbonyl)-4,6-dimethyl-2-pyridones were obtained in high yields from the self-condensation of N-alkyl-3-oxobutanamides in the presence of p-toluenesulfonic acid as a catalyst at 100-110°C for 11-24 hours without solvent.
- Furukawa, Isao,Fujisawa, Hironori,Kawazome, Mitsuru,Nakai, Yasuto,Ohta, Tetsuo
-
p. 1715 - 1717
(2007/10/03)
-
- Formation of dihydropyridone- and pyridone-based peptide analogs through aza-annulation of β-enamino ester and amide substrates with α-amido acrylate derivatives
-
The aza-annulation of β-enamino ester and amide substrates with the mixed anhydride of 2-acetamidoacrylic acid was used for the efficient construction of highly substituted α-acetamido δ-lactam products. With the α-acetamido substituent, lactam functionality, and γ-carboxylate group, these δ-lactam products represent an interesting class of conformationally restricted dipeptide analogs. The framework of this lactam hub is structurally related to that of an α-amino acid coupled with a β-amino acid. When α-amino esters derived from naturally occurring amino acids were used in the enamine formation step, subsequent aza-annulation led to branched peptide surrogates with two C-termini that extended from a common N-terminus. Oxidation of the aza-annulation products resulted in the generation of a planar system with peptide functionality radiating from the 1, 3, and 5 positions of the pyridone hub. Alternatively, pyridone products could be formed directly from the enamino amides by reaction with 2-phenyl-4-(ethoxymethylene)oxazolone. Subsequent hydrolysis of the acetamido and ester substituents of the N-benzylpyridones was selectively performed to access unique β-amino acid products. Formation of the mixed anhydride of this acid, followed by amide bond formation with the ester of an α-amino acid, allowed extension of the peptide chain from the dihydropyridone structure.
- Beholz, Lars G.,Benovsky, Petr,Ward, Donald L.,Barta, Nancy S.,Stille, John R.
-
p. 1033 - 1042
(2007/10/03)
-
- Lipase-catalyzed aminolysis and ammonolysis of β-ketoesters. Synthesis of optically active β-ketoamides.
-
Aminolysis and ammonolysis reactions of β-ketoesters catalyzed by Candida antarctica lipase are very efficient methods for the preparation of β- ketoamides. When racemic amines are used in these processes, the corresponding optically active β-ketoamides are obtained with moderate-high enantiomeric excesses.
- Garcia,Rebolledo,Gotor
-
p. 6935 - 6940
(2007/10/02)
-
- Chemoenzymatic aminolysis and ammonolysis of β-ketoesters
-
Candida antarctica lipase efficiently catalyses the preparation of β-ketoamides from β-ketoesters with primary aliphatic amines and ammonia.
- Garcia, Maria Jesus,Rebolledo, Francisca,Gotor, Vicente
-
p. 6141 - 6142
(2007/10/02)
-
- Effects of co-reagents on the reactions of alcohols with 6-methyl-1,3-oxazin-2,4(3H)-diones
-
Primary alcohols in the presence of Triton-B react preferentially at C-6 of N-alkyl-6-methyl-1,3-oxazin-2,4(3H)-diones (1a, 1b) to give corresponding N-alkyl-3-alkoxybut-2-enamides (2) but react at C-2 of 1,3-oxazin-2,4(3H)-dione (1c) to give N-acetoacetylcarbamates (4).The modes of these reactions have been rationalised.
- Singh, Harjit,Aggarwal, Pawan,Kumar, Subodh
-
p. 387 - 390
(2007/10/02)
-
- Heterocyclic Transformations. Part 3. Thiolate Ion-induced Transformations of 6-Methyl-1,3-oxazine-2,4(3H)-diones to 3-(Alkyl/arylthio)but-2-enamides
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Thiolate ions generated under phase-transfer catalytic conditions react exclusively at C-6 of 3-alkyl-6-methyl-1,3-oxazine-2,4(3H)-diones to give (E)- and (Z)-3-(alkylthio)but-2-enamides.With binucleophiles having at least one thiol group, the E+Z thiobutenamides are initially formed and their further transformation depends on the nature on the second nucleophile.The bulk of the N-3 substituent of the oxazine and the thiol exercise steric control on the rate and mode of the reaction.
- Kumar, Subodh,Chimni, Swapandeep Singh,Singh, Harjit
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p. 1391 - 1395
(2007/10/02)
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- Anion-induced reactions of primary alcohols at C-6 of 3-alkyl-6-methyl-1,3-oxazine-2,4(3H)-diones:Formation of N-alkyl-3-alkoxybuten-2-amides
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Primary alcohols react at C-6 of 3-alkyl-6-methyl-1,3-oxazine-2,4(3H)-diones(2) in the presence of Triton-B or potassium thiocyanate to give N-alkyl-3-alkoxybuten-2-amides(4).
- Singh, Harjit,Aggarwal, Pawan,Kumar, Subodh
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p. 950 - 951
(2007/10/02)
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- 1,3-Thiazines, XVI: 2-Thioxotetrahydro-1,3-thiazin-4-ones by Use of β-Propiolactones, Part 2
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Reactions of β-lactones with dithiocarbamates leading to 2 and cyclization of the products yielding 2-thioxo-tetrahydro-1,3-thiazin-4-ones 3 are described.With derivatives of diketene (β-propiolactones with exocyclic double bonds) no 1,3-thiazines 6 are obtained.Instead, the amides of β-ketoacids 7 are formed with the elimination of carbon disulfide.
- Hanefeld, Wolfgang,Glaeske, Gerd,Schulze-Weisschu, Petra
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p. 587 - 594
(2007/10/02)
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