- Dispiroketals in synthesis (Part 15): Simultaneous enantioselective and regioselective protection of glycerol by reaction with C2 symmetric (4S,4'S)-dimethyl-bis-dihydropyran
-
Glycerol was simultaneously, enantioselectively and regioselectively protected by reaction with (4S,4'S)-4,4'-dimethyl-3,3',4,4'-tetrahydro-6,6'-bis-2H-pyran to afford a dispiroketal product.
- Genicot,Ley
-
-
Read Online
- The Chiral Target of Daptomycin Is the 2R,2′S Stereoisomer of Phosphatidylglycerol
-
Daptomycin (dap) is an important antibiotic that interacts with the bacterial membrane lipid phosphatidylglycerol (PG) in a calcium-dependent manner. The enantiomer of dap (ent-dap) was synthesized and was found to be 85-fold less active than dap against
- Moreira, Ryan,Taylor, Scott D.
-
-
- Total Synthesis of the Alleged Structure of Crenarchaeol Enables Structure Revision**
-
Crenarchaeol is a glycerol dialkyl glycerol tetraether lipid produced exclusively in Archaea of the phylum Thaumarchaeota. This membrane-spanning lipid is undoubtedly the structurally most sophisticated of all known archaeal lipids and an iconic molecule in organic geochemistry. The 66-membered macrocycle possesses a unique chemical structure featuring 22 mostly remote stereocenters, and a cyclohexane ring connected by a single bond to a cyclopentane ring. Herein we report the first total synthesis of the proposed structure of crenarchaeol. Comparison with natural crenarchaeol allowed us to propose a revised structure of crenarchaeol, wherein one of the 22 stereocenters is inverted.
- Cunha, Ana V.,Havenith, Remco W. A.,Holzheimer, Mira,Minnaard, Adriaan J.,Schouten, Stefan,Sinninghe Damsté, Jaap S.
-
supporting information
p. 17504 - 17513
(2021/07/06)
-
- Dendritic Oligoglycerol Regioisomer Mixtures and Their Utility for Membrane Protein Research
-
Dendrons are an important class of macromolecules that can be used for a broad range of applications. Recent studies have indicated that mixtures of oligoglycerol detergent (OGD) regioisomers are superior to individual regioisomers for protein extraction. The origin of this phenomenon remains puzzling. Here we discuss the synthesis and characterization of dendritic oligoglycerol regioisomer mixtures and their implementation into detergents. We provide experimental benchmarks to support quality control after synthesis and investigate the unusual utility of OGD regioisomer mixtures for extracting large protein quantities from biological membranes. We anticipate that our findings will enable the development of mixed detergent platforms in the future.
- Urner, Leonhard H.,Goltsche, Katharina,Selent, Marleen,Liko, Idlir,Schweder, Marc-Philip,Robinson, Carol V.,Pagel, Kevin,Haag, Rainer
-
supporting information
p. 2537 - 2542
(2020/12/30)
-
- Synthesis and catalytic evaluation of acidic carbons in the etherification of glycerol obtained from biodiesel production
-
In this paper, the catalytic behaviour of carbonaceous system (Ccs) functionalized with –SO3H groups were studied in the etherification of refined (Gly) and crude glycerol (GlyC), with benzyl alcohol (BA). This Ccs was obtained by a synthetic method with low energetic cost in only 24 h. Its catalytic activity and selectivity were studied varying the catalyst percentage (2.5, 5 and 10 wt.%), the initial reactant molar ratio and temperature (between 80 and 120 °C). A very good catalytic performance was achieved (97 % conversion after 360 min of reaction), at 120 °C, Gly:BA = 3:1 and 10 wt.% of Ccs. The high activity can be attributed to high acid site density (6.4 mmol H+/g), that also allowed us to working at lower reaction temperature (100 °C) and with less catalyst concentration (2.5 wt.%), without observing significant loss in BA conversion. Monoether (ME1) was the major product of the reaction with 72 % selectivity. The material can be reused and still gives a notable conversion of BA (about 43 %) after three successive reuses. Finally, the Ccs was active and selective to the desired products in the etherification of crude glycerol (GlyC) derived of biodiesel industry. An important BA conversion (45 %) was obtained only reducing the water content of GlyC and without carrying out any other purification and/or neutralization treatment.
- Chiosso, María E.,Casella, Mónica L.,Merlo, Andrea B.
-
p. 107 - 114
(2020/10/29)
-
- Acylative desymmetrization of glycerol derivatives by chiral dmap derivatives
-
An efficient enantioselective acylative desymmetrization of glycerol was developed by using a chiral DMAP derivatives 1e having a 1,1-binaphthyl unit. The reactions required only 0.1 mol% of the catalyst and showed moderate to good enantioselectivity (up
- Ashihara, Kosuke,Mandai, Hiroki,Mitsudo, Koichi,Suga, Seiji
-
p. 1083 - 1090
(2021/06/21)
-
- Non-naturally Occurring Regio Isomer of Lysophosphatidylserine Exhibits Potent Agonistic Activity toward G Protein-Coupled Receptors
-
Lysophosphatidylserine (LysoPS), an endogenous ligand of G protein-coupled receptors, consists of l-serine, glycerol, and fatty acid moieties connected by phosphodiester and ester linkages, respectively. An ester linkage of phosphatidylserine can be hydrolyzed at the 1-position or at the 2-position to give 2-acyl lysophospholipid or 1-acyl lysophospholipid, respectively. 2-Acyl lysophospholipid is in nonenzymatic equilibrium with 1-acyl lysophospholipid in vivo. On the other hand, 3-acyl lysophospholipid is not found, at least in mammals, raising the question of whether the reason for this might be that the 3-acyl isomer lacks the biological activities of the other isomers. Here, to test this idea, we designed and synthesized a series of new 3-acyl lysophospholipids. Structure-activity relationship studies of more than 100 "glycol surrogate"derivatives led to the identification of potent and selective agonists for LysoPS receptors GPR34 and P2Y10. Thus, the non-natural 3-acyl compounds are indeed active and appear to be biologically orthogonal with respect to the physiologically relevant 1-and 2-acyl lysophospholipids.
- Nakamura, Sho,Sayama, Misa,Uwamizu, Akiharu,Jung, Sejin,Ikubo, Masaya,Otani, Yuko,Kano, Kuniyuki,Omi, Jumpei,Inoue, Asuka,Aoki, Junken,Ohwada, Tomohiko
-
p. 9990 - 10029
(2020/10/18)
-
- Synthesis and enantiospecific analysis of enantiostructured triacylglycerols containing n-3 polyunsaturated fatty acids
-
The stereospecific structure of triacylglycerols (TAGs) affects the bioavailability of fatty acids. Lack of enantiopure reference compounds and effective enantiospecific methods have hindered the stereospecific analysis of individual TAGs. Twelve novel enantiostructured AAB-type TAGs were synthesized containing one of the three n-3 polyunsaturated fatty acid: α-linolenic acid (ALA), eicosapentaenoic acid (EPA), or docosahexaenoic acid (DHA) in sn-1 or sn-3 position. These compounds formed six enantiomer pairs, which were separated with recycling high-performance liquid chromatography using chiral columns and UV detection. The chromatographic retention behavior of the enantiomers and the stereospecific elution order were studied. The enantiomer with an n-3 PUFA in the sn-1 position eluted faster than the enantiomer with the n-3 PUFA in the sn-3 position, regardless of the carbon chain length and number of double bonds of the PUFA. TAG enantiomers containing DHA exhibited highly different retention on the chiral column and were separated after the first column, whereas recycling was needed to separate the enantiomer pairs containing ALA or EPA. The system using two identical columns and one mobile phase, without sample derivatization, proved to be very effective also for peak purity assessment, confirming the enantiopurity of the synthesized structured TAGs being higher than 98 percent (96 percent ee).
- Gudmundsson, Haraldur G.,Haraldsson, Gudmundur G.,Kallio, Heikki,Kalpio, Marika,Linderborg, Kaisa M.,Magnússon, Jóhann D.,Yang, Baoru
-
-
- Highly regio- and enantio-selective hydrolysis of two racemic epoxides by GmEH3, a novel epoxide hydrolase from Glycine max
-
A novel epoxide hydrolase from Glycine max, designated GmEH3, was excavated based on the computer-aided analysis. Then, gmeh3, a GmEH3-encoding gene, was cloned and successfully expressed in E. coli Rosetta(DE3). Among the ten investigated rac-epoxides, GmEH3 possessed the highest and best complementary regioselectivities (regioselectivity coefficients, αS = 93.7% and βR = 97.2%) in the asymmetric hydrolysis of rac-m-chlorostyrene oxide (5a), and the highest enantioselectivity (enantiomeric ratio, E = 55.6) towards rac-phenyl glycidyl ether (7a). The catalytic efficiency (kcatS/KmS = 2.50 mM?1 s?1) of purified GmEH3 for (S)-5a was slightly higher than that (kcatR/KmR = 1.52 mM?1 s?1) for (R)-5a, whereas the kcat/Km (5.16 mM?1 s?1) for (S)-7a was much higher than that (0.09 mM?1 s?1) for (R)-7a. Using 200 mg/mL wet cells of E. coli/gmeh3 as the biocatalyst, the scale-up enantioconvergent hydrolysis of 150 mM rac-5a at 25 °C for 1.5 h afforded (R)-5b with 90.2% eep and 95.4% yieldp, while the kinetic resolution of 500 mM rac-7a for 2.5 h retained (R)-7a with over 99% ees and 43.2% yields. Furthermore, the sources of high regiocomplementarity of GmEH3 for (S)- and (R)-5a as well as high enantioselectivity towards rac-7a were analyzed via molecular docking (MD) simulation.
- Zhang, Chen,Li, Chuang,Zhu, Xiu-xiu,Liu, You-yi,Zhao, Jun,Wu, Min-chen
-
p. 2795 - 2803
(2020/09/01)
-
- POLY(PHOSPHOESTERS) FOR DELIVERY OF NUCLEIC ACIDS
-
Disclosed are polymers comprising the moiety A, which is a moiety of formula I: and pharmaceutically acceptable salts thereof, wherein R, R1, R2, L, n1 and n2 are as defined herein. These polymers are useful for delivering nucleic acids to subject. These polymers and pharmaceutically acceptable compositions comprising such polymers and nucleic acids can be useful for treating various diseases, disorders and conditions.
- -
-
-
- COMPOSITIONS AND METHODS FOR THE TREATMENT OF PARKINSON'S DISEASE
-
The invention relates to the compounds of formula I, formula II and/or formula III or its pharmaceutical acceptable salts, as well as polymorphs, solvates, enantiomers, stereoisomers and hydrates thereof. The pharmaceutical compositions comprising an effective amount of compound of formula I, formula II or formula III, and methods for treating or preventing Parkinson's disease may be formulated for oral, buccal, rectal, topical, transdermal, transmucosal, intravenous, parenteral administration, subcutaneous, depot, intramuscular, syrup, or injection. Such compositions may be used to treatment or management of Parkinson's disease as well as scleroderma, restless leg syndrome, hypertension and gestational hypertension.
- -
-
Page/Page column 46
(2020/05/19)
-
- Selective monochlorination of unsymmetrical vicinal diols with chlorinated iminium chlorides
-
Chlorinated iminium chlorides have been identified to promote the highly efficient and selective mono-chlorination of unsymmetrical vicinal diols. Vilsmeier reagent, namely, (chloromethylene)dimethyliminium chloride, enables highly reactive and regioselective chlorination of 1,2- and 1,3-diols featured one secondary benzylic hydroxy group and one primary aliphatic hydroxy group to give the corresponding 1,2- and 1,3-chlorohydrins. Viehe's salts (α,α-dichloro iminium salts) exhibit excellent reactivity and good selectivity for vicinal diols to give the corresponding chlorohydrin carbamates via a cyclic intermediate in situ. The chlorination protocols tolerate diverse functional groups, including halogens, naphthalene rings, nitro, and cyano. Moreover, the optical purity of chiral diols could be retained during this chlorination reaction.
- Li, Chengyang,Li, Xiaotong,Wang, Yu,Wu, Xiaoyu,Xie, Xiaomin,Yang, Liqun,Zhang, Zhaoguo
-
supporting information
(2020/03/23)
-
- HYDROPHOBIC ACID ADDITION SALTS AND PHARMACEUTICAL FORMULATIONS THEREOF
-
The invention provides hydrohphobic drug salts and pharmaceutical compositions comprising such salts. The invention fourther provides compositions for delivering poorly soluble drugs, including hydrophobic drug salts.
- -
-
Page/Page column 81
(2019/05/22)
-
- Preparation of benzothiazolyl-decorated nanoliposomes
-
Amyloid β (Aβ) species are considered as potential targets for the development of diagnostics/therapeutics towards Alzheimer’s disease (AD). Nanoliposomes which are decorated with molecules having high affinity for Aβ species may be considered as potential carriers for AD theragnostics. Herein, benzothiazolyl (BTH) decorated nanoliposomes were prepared for the first time, after synthesis of a lipidic BTH derivative (lipid-BTH). The synthetic pathway included acylation of bis(2-aminophenyl) disulfide with palmitic acid or palmitoyl chloride and subsequent reduction of the oxidized dithiol derivative. The liberated thiols were able to cyclize to the corresponding benzothiazolyl derivatives only after acidification of the reaction mixture. Each step of the procedure was monitored by HPLC analysis in order to identify all the important parameters for the formation of the BTH-group. Finally, the optimal methodology was identified, and was applied for the synthesis of the lipid-BTH derivative. BTH-decorated nanoliposomes were then prepared and characterized for physicochemical properties (size distribution, surface charge, physical stability, and membrane integrity during incubation in presence of buffer and plasma proteins). Pegylated BTH-nanoliposomes were demonstrated to have high integrity in the presence of proteins (in comparison to non-peglated ones) justifying their further exploitation as potential theragnostic systems for AD.
- Mourtas, Spyridon,Christodoulou, Panayiota,Klepetsanis, Pavlos,Gatos, Dimitrios,Barlos, Kleomenis,Antimisiaris, Sophia G.
-
-
- Racemization of α-Alkyl-β-Keto Esters and Enantioselective Total Synthesis of Two C-2′′′Epimers of Plant Glycerolipid Santinol C
-
It is broadly believed that optically active α-alkyl-β-keto esters racemize very quickly. Nevertheless, no one really knows how fast the racemization is. In fact, such species are hardly attainable to date. Now, a facile entry to these greatly understudied esters has been found and their racemization has been studied for the first time. The results showed that under neutral or slightly acidic conditions such species were much more stable than one might expect, though they did racemize rapidly under basic conditions. In light of the new findings, santinol C was also synthesized in enantiopure forms.
- Wu, Wen-Ju,Li, Mei-Mei,Liu, Bo,Wu, Yikang
-
p. 3169 - 3173
(2019/05/21)
-
- Glycerol conversion to high-value chemicals: The implication of unnatural α-amino acid syntheses using natural resources
-
Glycerol derivatives are an important class of compounds, which have great applications as basic structural building blocks in organic synthesis. O-Benzylglycerol was oxidised to produce a high-value compound in high yield using a NaOtBu-O2 system. Furthermore, the synthetic utility of the resulting product was demonstrated by its transformation into unnatural α-amino acids, thus showing the valorisation of glycerol biomass.
- Park, Yun Ji,Yang, Jung Woon
-
supporting information
p. 2615 - 2620
(2019/06/03)
-
- Regioselective Ring-Opening of Glycidol to Monoalkyl Glyceryl Ethers Promoted by an [OSSO]-FeIII Triflate Complex
-
A FeIII-triflate complex, bearing a bis-thioether-di-phenolate [OSSO]-type ligand, was discovered to promote the ring-opening of glycidol with alcohols under mild reaction conditions (0.05 mol % catalyst and 80 °C). The reaction proceeded with high activity (initial turnover frequency of 1680 h?1 for EtOH) and selectivity (>95 %) toward the formation of twelve monoalkyl glyceryl ethers (MAGEs) in a regioselective fashion (84–96 % yield of the non-symmetric regioisomer). This synthetic approach allows the conversion of a glycerol-derived platform molecule (i.e., glycidol) to high-value-added products by using an Earth-crust abundant metal-based catalyst.
- Monica, Francesco Della,Ricciardi, Maria,Proto, Antonio,Cucciniello, Raffaele,Capacchione, Carmine
-
p. 3448 - 3452
(2019/08/01)
-
- Site-Selective Mono-Oxidation of 1,2-Bis(boronates)
-
Site-selective oxidation of vicinal bis(boronates) is accomplished through the use of trimethylamine N-oxide in 1-butanol solvent. The reaction occurs with good efficiency and selectivity across a range of substrates, providing 2-hydro-1-boronic esters which are shown to be versatile intermediates in the synthesis of chiral building blocks.
- Yan, Lu,Morken, James P.
-
supporting information
p. 3760 - 3763
(2019/05/24)
-
- PYRAZOLE DERIVATIVE, OR PHARMACEUTICALLY ACCEPTABLE SALT THEREOF
-
[Problem] The present invention is to provide a novel pyrazole derivative, or a pharmaceutically acceptable salt thereof, a pharmaceutical composition comprising the same, and a pharmaceutical use thereof. [Solution] The present invention provides a compound represented by the formula (I) or a pharmaceutically acceptable salt thereof, which has TRPM8 inhibitory effects: wherein ring A is C6-10 aryl or the like; X is CR4a or the like; R1 and R2 are a hydrogen atom or the like; R3 is a hydrogen atom or the like; R4 is a hydrogen atom or the like; ring B is C6-10 aryl or the like; R5 is a hydrogen atom or the like; R6a is a hydrogen atom or the like; R7a is a hydrogen atom or the like; R7b is a hydrogen atom or the like; R6b is a hydrogen atom or the like; R8 is a hydrogen atom or the like; n is 0, 1 or 2. Therefore, the compound represented by the formula (I) of the present invention or a pharmaceutically acceptable salt thereof is useful as an agent for treating or preventing diseases or symptoms caused by hyperexcitability or disorder of afferent neurons.
- -
-
Paragraph 0242
(2018/05/16)
-
- Method for producing pyrazole derivative
-
PROBLEM TO BE SOLVED: To provide a method for producing a pyrazole derivative. SOLUTION: There is provided the method for producing a pyrazole derivative by using a compound represented by formula (IIC), (IID) or (III) and a compound represented by formula (IV). SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
- -
-
Paragraph 0259
(2018/08/30)
-
- Synthetic method of alkynyl-modified phospholipid derivative for preparing functional phospholipid giant vesicle
-
The invention discloses a synthetic method of an alkynyl-modified phospholipid derivative for preparing a functional phospholipid giant vesicle. The method comprises the following steps: with solketalas a starting raw material, selectively introducing an alkyl chain through benzyl protection, deprotection and DCC-DMAP catalytic condensation, synthesizing 3-hydroxy-1,2- dipalmitin, using 2-chloro-2-oxo-1,3,2-dioxaphospholane as a phosphorylation reagent, carrying out ring opening reaction by using 1-dimethylamine-2-allylene, and preparing the alkynyl-modified phospholipid derivative. The method is simple in synthetic route, a highly toxic reagent does not need to be used, and the phospholipid giant vesicle with an adjustable surface reactivity group density can be prepared by mixing the obtained alkynyl-modified phospholipid derivative and common phospholipid available in the market according to a certain proportion. The possibility is provided for the further stabilization and functionalization of this type of the vesicle.
- -
-
-
- Synthesis process of novel compound phosphatidyl 3-hydroxypropionitrile
-
The invention relates to a synthesis process of a novel compound phosphatidyl 3-hydroxypropionitrile. The synthesis process comprises the following steps: using acetone glycerol as a starting material; protecting exposed hydroxyl with benzyl; removing a ketal protecting group to obtain two exposed hydroxyls; then, esterifying with stearic acid; removing benzyl protection to obtain the exposed hydroxyl; reacting with a chlorophosphine compound to obtain a phosphine oxide compound; oxidizing to obtain phosphine oxide; and removing one molecular propyl nitrile to obtain a final product phosphatidyl 3-hydroxypropionitrile.
- -
-
Paragraph 0010
(2018/09/21)
-
- Evaluating Ylehd, a recombinant epoxide hydrolase from: Yarrowia lipolytica as a potential biocatalyst for the resolution of benzyl glycidyl ether
-
Glycidyl ethers and their vicinal diols are important building blocks in the organic synthesis of anti-cancer and anti-obesity drugs. Ylehd, an epoxide hydrolase from tropical marine yeast Yarrowia lipolytica, was explored for its enantioselective propert
- Bendigiri, Chandrika,Harini,Yenkar, Sajal,Zinjarde, Smita,Sowdhamini,Ravikumar, Ameeta
-
p. 12918 - 12926
(2018/04/16)
-
- Hydrogenation of CO2-Derived Carbonates and Polycarbonates to Methanol and Diols by Metal–Ligand Cooperative Manganese Catalysis
-
The first base-metal-catalysed hydrogenation of CO2-derived carbonates to alcohols is presented. The reaction proceeds under mild conditions in the presence of a well-defined manganese complex with a loading as low as 0.25 mol %. The non-precious-metal homogenous catalytic system provides an indirect route for the conversion of CO2 into methanol with the co-production of value-added (vicinal) diols in yields of up to 99 %. Experimental and computational studies indicate a metal–ligand cooperative catalysis mechanism.
- Zubar, Viktoriia,Lebedev, Yury,Azofra, Luis Miguel,Cavallo, Luigi,El-Sepelgy, Osama,Rueping, Magnus
-
supporting information
p. 13439 - 13443
(2018/09/21)
-
- Raw and waste plant materials as sources of fungi with epoxide hydrolase activity. Application to the kinetic resolution of aryl and alkyl glycidyl ethers
-
The by-products of olive oil production can be used as sources of microbial strains. Penicillium sp., Aspergillus terreus, Penicillium aurantiogriseum, Aspergillus tubingensis and Aspergillus niger were selected on the basis of their epoxide-hydrolyzing activity towards racemic rac-glycidyl phenyl ether. We studied the effect on enzymatic activity of adding styrene oxide to the growth medium. It induced the biosynthesis of epoxide hydrolases and reduced cell growth. The resolution capacity of the five fungi was tested on rac-glycidyl phenyl ether, rac-benzyl glycidyl ether, rac-1,2-epoxyhexane and rac-1,2-epoxyoctane. The resolution of rac-glycidyl phenyl ether by A. niger, rac-benzyl glycidyl ether by P. aurantiogriseum and A. terreus, rac-1,2-epoxyhexane by A. tubingensis and rac-1,2-epoxyoctane by A. terreus provided (S)-3-phenoxy-1,2-propanediol (45.1% yield, 51.4% ee), (R)-3-benzyloxy-1,2-propanediol (40.8% yield, 43.3% ee), (S)-3-benzyloxy-1,2-propanediol (45.4% yield, 45.6% ee), (R)-1,2-hexanediol (70.4% yield, 24.4% ee) and (R)-1,2-octanediol (21.4% yield, 27.5% ee), respectively. The (R)-enantiopreference of the epoxide hydrolases from P. aurantiogriseum is unprecedented.
- Dolcet, Marta,Torres, Mercè,Canela-Garayoa, Ramon
-
-
- COMPOSITIONS AND METHODS FOR DELIVERY OF THERAPEUTIC AGENTS
-
This disclosure provides improved lipid-based compositions, including lipid nanoparticle compositions, and methods of use thereof for delivering agents in vivo including nucleic acids and proteins. These compositions are not subject to accelerated blood clearance and they have an improved toxicity profile in vivo.
- -
-
-
- Synthesis and immunological study of a wall teichoic acid-based vaccine against E. faecium U0317
-
A repeat unit of cell wall teichoic acids (WTA) isolated from E. faecium U0317 was chemically synthesized efficiently by a stepwise strategy. It was derivatized with a 5-aminopentanyl linker to facilitate conjugation with carrier proteins KLH and HSA. Immunological studies of the KLH conjugate 1 demonstrated that it could provoke robust immune responses and high titers of IgG antibodies, which could successfully recognize the synthesized WTA repeat unit 3. This result suggested that synthetic glycoconjugate 1 could be a promising vaccine candidate against E. faecium for further studies.
- Zhou, Zhifang,Ding, Wenzhang,Li, Chen,Wu, Zhimeng
-
p. 205 - 219
(2017/11/15)
-
- Copper-catalyzed/mediated borylation reactions of epoxides with diboron reagents: access to β-hydroxyl boronic esters
-
We report the first copper-catalyzed/mediated borylative ring opening reaction of epoxides. This process represents a direct borylative C(sp3)-O bond cleavage of terminal epoxide substrates with commercially available diboron reagents. A wide range of epoxides with different functional groups are involved, and were subsequently converted to the corresponding β-hydroxyl boronic esters smoothly. Moreover, the ring opening product β-pinacol boronate alcohol provided a more beneficial approach for the formation of C-C and C-N bonds.
- Ahmed, Ebrahim-Alkhalil M. A.,Lu, Xi,Gong, Tian-Jun,Zhang, Zhen-Qi,Xiao, Bin,Fu, Yao
-
p. 909 - 912
(2017/01/17)
-
- Synthesis, Characterization and Catalytic Application of Pyridine-Bridged N-Heterocyclic Carbene–Ruthenium Complexes in the Hydrogenation of Carbonates
-
A series of bulky pyridine-bridged NHC–Ru complexes have been rationally designed and synthesized; these exhibited very high catalytic activity in the hydrogenation of cyclic and linear carbonates under mild reaction conditions. In the presence of catalytic amounts of a weak base, a broad range of substrates with different ring size and steric bulk were well tolerated, providing methanol and the corresponding diols in excellent yields with a catalyst loading as low as 0.5 mol %.
- Chen, Jiangbo,Zhu, Haibo,Chen, Jinjin,Le, Zhang-Gao,Tu, Tao
-
supporting information
p. 2809 - 2812
(2017/10/23)
-
- Efficient diastereoselective synthesis of a new class of azanucleosides: 2′-homoazanucleosides
-
Azanucleosides, sugar-modified nucleoside analogues containing a 4′ nitrogen atom, have shown a lot of therapeutic potential, e.g. as anti-cancer and antiviral agents. We report the synthesis of a series of 2’-homoazanucleosides, in which the nucleobase is attached to the 2’-position of the pyrrolidine ring via a methylene linker. A suitable orthogonally protected iminosugar was synthesized by ring closing metathesis and dihydroxylation as key steps and further converted to a series of 8 nucleoside analogues through Mitsunobu reaction with suitably protected nucleobases. The 5′ position of the adenine analogue was then further derivatized with thiols to afford 2 additional compounds. The final compounds were evaluated for biological activity.
- Bouton, Jakob,Van Hecke, Kristof,Van Calenbergh, Serge
-
p. 4307 - 4316
(2017/06/30)
-
- Asymmetric hydrolysis of styrene oxide by PvEH2, a novel Phaseolus vulgaris epoxide hydrolase with extremely high enantioselectivity and regioselectivity
-
A novel EH from Phaseolus vulgaris, PvEH2, was discovered based on the computer-aided analysis, and its encoding gene was cloned and expressed in E. coli Rossetta (DE3). The substrate spectrum of recombinant (re) PvEH2 was assayed, among which the enantiomeric ratio of rePvEH2 towards racemic styrene oxide (rac-1a) was > 200, while its regioselectivity coefficients, αS and βR, towards (S)- and (R)-1a were 99.1 and 69.8%, respectively. The asymmetric hydrolysis of 20 mM rac-1a by rePvEH2-expressing whole cells was performed at 25 °C, retaining (R)-1a with > 99.5% ees and 49.4% yield and producing (R)-phenyl-1,2-ethanediol (1b) with 96.2% eep and 49.7% yield in 40 min.
- Li, Chuang,Hu, Die,Zong, Xun-Cheng,Deng, Chao,Feng, Lei,Wu, Min-Chen,Li, Jian-Fang
-
-
- A 1,2-O-double-hexadecyl-rac-glycerol synthesis method (by machine translation)
-
The invention discloses a 1,2-O-double-hexadecyl-rac-glycerol synthesis method, comprises first acetone mixed with the glycerine, to the toluene sulfonic acid as catalyst synthesis acetone compression glycerin, and then the acetone compression glycerin C1 hydroxy benzyl protection for 1-phenylmethyl -2,3-isopropylidene-rac-glycerin, then using a certain concentration of hydrochloric acid deprotected, to obtain 3-benzyloxy -1,2-propylene glycol, with the bromo-hexadecane william abdicates reaction occurred 1-O-benzyl -2,3-O-twenty-six alkyl glycerin, finally the hydrogen obtained remove benzyl under the action of a Pd 1,2-O-double-hexadecyl-rac-glycerin. The present invention provides a new synthetic 1,2-O-double-hexadecyl-rac-glycerin ways. (by machine translation)
- -
-
Paragraph 0065; 0066
(2016/10/17)
-
- Synthesis of Monoalkyl Glyceryl Ethers by Ring Opening of Glycidol with Alcohols in the Presence of Lewis Acids
-
The present work deals with the production of monoalkyl glyceryl ethers (MAGEs) through a new reaction pathway based on the reaction of glycidol and alcohols catalyzed by Lewis acid-based catalysts. Glycidol is quantitatively converted with high selectivity (99 %) into MAGEs under very mild reaction conditions (80 °C and 0.01 mol % catalyst loading) in only 1 h using Al(OTf)3 or Bi(OTf)3 as catalyst. The proposed method enhances the choice of possible green synthetic approaches for the production of value-added products such as MAGEs.
- Cucciniello, Raffaele,Ricciardi, Maria,Vitiello, Rosa,Di Serio, Martino,Proto, Antonio,Capacchione, Carmine
-
p. 3272 - 3275
(2016/12/16)
-
- Aerobic Acetoxyhydroxylation of Alkenes Co-catalyzed by Organic Nitrite and Palladium
-
An aerobic acetoxyhydroxylation of alkenes cooperatively catalyzed by organic nitrite and palladium at room temperature using clean and cheap air as the sole oxidant has been developed. Various vicinal diols, diacetoxyalkanes, and dihalogenoalkanes have been synthesized. The gram-scale synthesis has also been approached. Vicinal difluorination and dichlorolation products have also been achieved via this reaction.
- Chen, Xian-Min,Ning, Xiao-Shan,Kang, Yan-Biao
-
supporting information
p. 5368 - 5371
(2016/11/02)
-
- Percarboxylic Acid Oxidation of α-Hydroxy-Substituted Alkoxyallenes: The Unexpected Formation of Acyloxy-Substituted 1,2-Diketones and the Synthesis of Functionalized Quinoxalines
-
Treatment of α-hydroxy-substituted methoxyallene derivatives with meta-chloroperbenzoic acid provided acyloxy-substituted 1,2-diketones in moderate yields. A mechanism for the formation of these unexpected products is proposed. The configuration of the enantiopure compound (S)-1-(3-methylquinoxalin-2-yl)-1-(4-nitrobenzoyl?oxy)propan-2-yl 3-chlorobenzoate - determined by X-ray crystal structure analysis - indicates the intermediacy of a carbenium ion during formation of the 1,2-diketones. The functionalized 1,2-diketones are valuable starting materials for a variety of products as demonstrated by the synthesis of quinoxalines, an imidazole derivative, and electron-deficient alkenes.
- Klemme, Robby,Bentz, Christoph,Zukowski, Tomasz,Schefzig, Luise,Lentz, Dieter,Reissig, Hans-Ulrich,Zimmer, Reinhold
-
supporting information
p. 1491 - 1501
(2016/05/24)
-
- Chemo- and Regioselective Functionalization of Polyols through Catalytic C(sp3)-C(sp3) Kumada-Type Coupling of Cyclic Sulfate Esters
-
This contribution describes a copper-catalyzed, C(sp3)-C(sp3) cross-coupling reaction of cyclic sulfate esters, a distinct class of electrophilic derivatives of polyols, with alkyl Grignard reagents to afford functionalized alcohol products in good yields. The method is operationally simple and highlights the potential of cyclic sulfate esters as highly reactive substrates in catalytic, chemoselective polyol transformations.
- Ramírez-Contreras, Rodrigo,Morandi, Bill
-
supporting information
p. 3718 - 3721
(2016/08/16)
-
- Synthesis of unsaturated phosphatidylinositol 4-phosphates and the effects of substrate unsaturation on SopB phosphatase activity
-
In this paper evidence is presented that the fatty acid component of an inositide substrate affects the kinetic parameters of the lipid phosphatase Salmonella Outer Protein B (SopB). A succinct route was used to prepare the naturally occurring enantiomer of phosphatidylinositol 4-phosphate (PI-4-P) with saturated, as well as singly, triply and quadruply unsaturated, fatty acid esters, in four stages: (1) The enantiomers of 2,3:5,6-O-dicyclohexylidene-myo-inositol were resolved by crystallisation of their di(acetylmandelate) diastereoisomers. (2) The resulting diol was phosphorylated regio-selectively exclusively on the 1-O using the new reagent tri(2-cyanoethyl)phosphite. (3) With the 4-OH still unprotected, the glyceride was coupled using phosphate tri-ester methodology. (4) A final phosphorylation of the 4-O, followed by global deprotection under basic then acidic conditions, provided PI-4-P bearing a range of sn-1-stearoyl, sn-2-stearoyl, -oleoyl, -γ-linolenoyl and arachidonoyl, glycerides. Enzymological studies showed that the introduction of cis-unsaturated bonds has a measurable influence on the activity (relative Vmax) of SopB. Mono-unsaturated PI-4-P exhibited a five-fold higher activity, with a two-fold higher KM, over the saturated substrate, when presented in DOPC vesicles. Poly-unsaturated PI-4-P showed little further change with respect to the singly unsaturated species. This result, coupled with our previous report that saturated PI-4-P has much higher stored curvature elastic stress than PI, supports the hypothesis that the activity of inositide phosphatase SopB has a physical role in vivo. This journal is
- Furse, Samuel,Mak, Lokhang,Tate, Edward W.,Templer, Richard H.,Ces, Oscar,Woscholski, Rüdiger,Gaffney, Piers R. J.
-
p. 2001 - 2011
(2015/03/05)
-
- Selective functionalization of the primary hydroxy group in triols
-
A procedure was suggested for preparing functionally substituted 1,2-diols by O-alkylation of hydroxyalkyl-1,3-dioxacyclanes with alkyl halides, followed by acid hydrolysis. The conditions for selective cleavage of the ethers obtained were found. (2,2-Dimethyl-1,3-dioxolan-4-yl)methyl benzoate under the conditions of acid deacetalization undergoes saponification of the ester group.
- Raskil'Dina,Valiev,Sultanova,Zlotskii
-
p. 1599 - 1604
(2016/02/18)
-
- Supramolecular assemblies of novel aminonucleoside phospholipids and their bonding to nucleic acids
-
A novel class of aminonucleoside phospholipids has been developed. These molecules could spontaneously assemble into supramolecular structures including multilamellar organization, hydrogels, superhelical strands, and vesicles. Their ability to bind to DNA by hydrogen bonding and π-π stacking interactions was investigated by many means. This journal is
- Pan, Delin,Sun, Jing,Jin, Hongwei,Li, Yating,Li, Liyu,Wu, Yun,Zhang, Lihe,Yang, Zhenjun
-
supporting information
p. 469 - 472
(2015/02/19)
-
- The role of mesoporosity and Si/Al ratio in the catalytic etherification of glycerol with benzyl alcohol using ZSM-5 zeolites
-
A comparative study of the influence of three different acid solids as catalysts (conventional zeolites Z15c with Si/Al = 19.5 and Z40c with Si/Al = 48.2, and a hierarchical zeolite Z40c-H with Si/Al = 50.0) for the etherification of glycerol with benzyl alcohol was performed. The catalytic activity and selectivity of these zeolites was elucidated at different catalyst contents. Three different ethers (3-benzyloxy-1,2-propanediol, which is a mono-benzyl-glycerol ether (MBG) and 1,3-dibenzyloxy-2-propanol, which is a di-benzyl-glycerol ether (DBG) and dibenzyl ether (DBz) were identified as the main products. MBG was the major product of the reaction catalyzed by the microporous Z15c zeolite with low Si/Al molar ratio, whereas DBG was formed in higher yield with the use of microporous Z40c and hierarchical Z40c-H zeolites, both of them having a similar high Si/Al molar ratio (≈50 MBG is a value-added product andit is obtained with good yield and selectivity when using the conventional zeolite Z15c as a catalyst.Under the best conditions tested, i.e., 25 mg of catalyst for 8 h at 120°C, a 62% of conversion was obtainedwithout the need of solvent, with an excellent 84% selectivity toward the MBG and no formation of DBz.
- Gonzalez-Arellano, Camino,Grau-Atienza, Aida,Serrano, Elena,Romero, Antonio A.,Garcia-Martinez, Javier,Luque, Rafael
-
-
- Glycerol etherification with benzyl alcohol over sulfated zirconia catalysts
-
Glycerol (GLY) etherification with benzyl alcohol (BA) was conducted with different zirconia-based heterogeneous acid catalysts, aiming to produce mono- (ME) and dibenzyl glycerol ethers (DE). Physicochemical properties of the prepared catalysts were obtained through XRD, SEM and adsorption of ammonia. The catalytic tests were performed at different temperatures (120-140°C) and initial reactant mass ratios (GLY:BA 1:1 and 2:1). The highest BA conversions were obtained with the catalyst having the highest sulfuric acid content (2S/ZrO2). An increase in the reaction temperature and the GLY:BA initial mass ratio led to an increase in the BA conversion. Two kinetic models (a potential and a hyperbolic approach) were proposed to describe the process performance, including not only reactants evolution with time, but also that of ME, DE and the undesired self-condensation product of BA (benzyl ether, BE). Kinetic parameters for each model were estimated by data fitting and both models were able to accurately describe the evolution of the system, in terms of reactants and product distribution as a function of time under the experimental conditions studied.
- Jaworski, María A.,Rodríguez Vega, Sergio,Siri, Guillermo J.,Casella, Mónica L.,Romero Salvador, Arturo,Santos López, Aurora
-
-
- Synthesis of Novel C-Pivot Lariat 18-Crown-6 Ethers and Their Efficient Purification
-
The syntheses of various lariat ethers including several not previously reported and their efficient purification are presented. The synthesis route brings together reactions from a variety of previous works leading to a robust and generalized approach to these C-pivot lariats. The main steps are condensation of functionalized diols with pentaethylene glycol ditosylate in the presence of potassium as a templating cation. Purification of the final products was achieved without chromatography by extracting from an aqueous potassium hydroxide solution.
- Jana, Susovan,Suresh, Vallabh,Lepore, Salvatore D.
-
p. 1977 - 1980
(2015/09/01)
-
- Synthesis of enantiopure structured triacylglycerols
-
The synthesis of nine enantiopure structured triacylglycerols (TAGs) of the AAB type is described, all possessing the (S)-absolute configuration. Six of them possess one saturated and two identical unsaturated fatty acyl chains, whereas the remaining three possess two identical saturated fatty acids along with one unsaturated fatty acid. The former group was synthesized by a five-step chemoenzymatic route involving a highly regioselective immobilized Candida antarctica lipase, starting from enantiopure (R)-solketal. The second group was prepared by a fully chemical five-step approach based on the same chiral precursor. Such enantiopure TAGs are strongly required as standards for the enantiospecific analysis of intact TAGs in fats and oils.
- Kristinsson, Bjoern,Linderborg, Kaisa M.,Kallio, Heikki,Haraldsson, Gudmundur G.
-
p. 125 - 132
(2014/02/14)
-
- SUBSTITUTED SPIROPYRIDO[1,2-a]PYRAZINE DERIVATIVE AND PHARMACEUTICAL USE OF SAME AS HIV INTEGRASE INHIBITOR
-
Provided is a substituted spiropyrido[1,2-a]pyrazine derivative or a pharmaceutically acceptable salt thereof, which is useful as an anti-HIV agent. The present invention relates to a compound represented by the following formula [I] or [II] or a pharmace
- -
-
Paragraph 1550; 1551; 1552
(2014/08/19)
-
- A new enantioselective synthesis of the anti-Parkinson agent safinamide
-
An alternative highly enantioselective synthesis of the anti-Parkinson agent safinamide from simple, commercially available, starting materials is described. The protocol might also be useful in the synthesis of structural variants of safinamide, such as ralfinamide or related analogues. Georg Thieme Verlag Stuttgart New York.
- Reddi, Anjaneyulu,Mujahid, Mohammad,Sasikumar, Murugesan,Muthukrishnan, Murugan
-
p. 1751 - 1756
(2014/07/08)
-
- Total synthesis of an immunomodulatory phosphoglycolipid from thermophilic bacteria
-
A method for the stereocontrolled synthesis of a bacterial phosphoglycolipid (PGL1) isolated from thermophilic bacteria is described. The key features of the synthesis include a highly α-selective glycosylation reaction between a trichloroacetimidate donor and a D-lyxose-derived primary alcohol acceptor and the late-stage incorporation of the phospholipid. Copyright
- Lin, Hong-Jyune,Adak, Avijit Kumar,Reddy, L. Vijaya Raghava,Wu, Shih-Hsiung,Lin, Chun-Cheng
-
p. 7989 - 7998
(2013/07/19)
-
- Optically active monoacylglycerols: Synthesis and assessment of purity
-
Despite their simple structures, synthesis of 1(or 3)-acyl-sn-glycerols remains a challenge that cannot be ignored because of facile acyl migrations, which not only complicate the synthesis but also make direct GC or HPLC analysis unfeasible. Assessment of the optical purity of monoacylglycerols has, to date, relied almost exclusively on specific rotation data, which are small in value and thus insensitive to impurities. Now, a simple means to "magnify" the small specific rotations has been found, along with practical methods for the measurement of both 1,2-and 1,3-acyl migrations, which offer a convenient and straightforward alternative to Mori's NMR analysis of Mosher esters. With the aid of these methods, a range of conditions for deacetonide removal were examined en route to the synthesis of two natural monoacylglycerols. Refined hydrolysis conditions, along with useful knowledge about the solubility and reactivity of substrates with an ultra long alkyl chain are also presented. Copyright
- Chen, Chao-Yuan,Han, Wei-Bo,Chen, Hui-Jun,Wu, Yikang,Gao, Po
-
p. 4311 - 4318
(2013/07/26)
-
- ANTIBACTERIAL AGENTS
-
Antibacterial compounds of formula (I) are provided, as well as stereoisomers and pharmaceutically acceptable salts thereof; pharmaceutical compositions comprising such compounds; methods of treating bacterial infections by the administration of such compounds; and processes for the preparation of such compounds.
- -
-
Page/Page column 169
(2013/12/03)
-
- Acyclic nucleoside phosphonates containing a second phosphonate group are potent inhibitors of 6-oxopurine phosphoribosyltransferases and have antimalarial activity
-
Acyclic nucleoside phosphonates (ANPs) that contain a 6-oxopurine base are good inhibitors of the Plasmodium falciparum (Pf) and Plasmodium vivax (Pv) 6-oxopurine phosphoribosyltransferases (PRTs). Chemical modifications based on the crystal structure of 2-(phosphonoethoxy)ethylguanine (PEEG) in complex with human HGPRT have led to the design of new ANPs. These novel compounds contain a second phosphonate group attached to the ANP scaffold. {[(2-[(Guanine-9H-yl) methyl]propane-1,3-diyl)bis(oxy)]bis(methylene)}diphosphonic acid (compound 17) exhibited a Ki value of 30 nM for human HGPRT and 70 nM for Pf HGXPRT. The crystal structure of this compound in complex with human HGPRT shows that it fills or partially fills three critical locations in the active site: the binding sites of the purine base, the 5′-phosphate group, and pyrophosphate. This is the first HG(X)PRT inhibitor that has been able to achieve this result. Prodrugs have been synthesized resulting in IC50 values as low as 3.8 μM for Pf grown in cell culture, up to 25-fold lower compared to the parent compounds.
- Keough, Dianne T.,?pa?ek, Petr,Hocková, Dana,Tichy, Tomá?,Vrbková, Silvie,Slavětínská, Lenka,Janeba, Zlatko,Naesens, Lieve,Edstein, Michael D.,Chavchich, Marina,Wang, Tzu-Hsuan,De Jersey, John,Guddat, Luke W.
-
p. 2513 - 2526
(2013/05/22)
-
- Asymmetric diboration of terminal alkenes with a rhodium catalyst and subsequent oxidation: Enantioselective synthesis of optically active 1,2-diols
-
Pin it down: A highly enantioselective diboration of terminal alkenes with chiral 1 and bis(pinacolato)diboron (B2pin2) was realized. Subsequent oxidation of the diboron adducts with sodium peroxoborate readily gave the corresponding optically active 1,2-diols in high yields and high enantioselectivities. Copyright
- Toribatake, Kenji,Nishiyama, Hisao
-
supporting information
p. 11011 - 11015
(2013/10/22)
-
- NITROIMIDAZOOXAZINES AND THEIR USES IN ANTI-TUBERCULAR THERAPY
-
The present invention relates to novel nitroimidazooxazines, to their preparation, and to their use as drugs for treating Mycobacterium tuberculosis and other microbial infections, either alone or in combination with other anti-infective treatments.
- -
-
Page/Page column 15
(2012/02/06)
-