10340-23-5Relevant articles and documents
An Approach to the Syntheiss of (-)-Lipstatin by Wittig Reaction and Lewis Acid-promoted Cycloaddition
Pons, Jean-Marc,Pommier, Agnes,Lerpiniere, Joan,Kocienski, Philip
, p. 1549 - 1552 (1993)
The β-lactone moiety of (-)-lipstatin 1, a potent inhibitor of pancreatic lipase, is prepared via a Lewis acid-promoted cycloaddition between hexyltrimethylsilyl ketene 3 and the (Z,Z)-dienic aldehyde 4, obtained from hexenal by two stereoselective Wittig reactions.
Soybean lipoxygenase and horseradish peroxidase catalysed asymmetric oxidation-reduction sequence for the synthesis of chiral (Z,E) diene-diols
Yadav,Nanda,Bhaskar Rao
, p. 787 - 788 (2001)
Unnatural synthetic substrates with a properly spaced prosthetic modifier having non-ionic hydroxy terminus undergoes soybean lipoxygenase catalysed asymmetric peroxidation followed by horseradish peroxidase induced reduction affords (Z, E)-dienediol in high enantiomeric excess.
Exploitation of a Multienzymatic Stereoselective Cascade Process in the Synthesis of 2-Methyl-3-Substituted Tetrahydrofuran Precursors
Brenna, Elisabetta,Crotti, Michele,Gatti, Francesco G.,Marinoni, Ludovico,Monti, Daniela,Quaiato, Sara
, p. 2114 - 2122 (2017)
Enantiopure 2-methyl-3-substituted tetrahydrofurans are key precursors of several biologically active products (drugs, flavors, and agrochemicals). Thus, a stereocontrolled and efficient methodology for the obtainment of these synthons is highly desirable. We exploited a two-step multienzymatic stereoselective cascade reduction of α-bromo-α,β-unsaturated ketones to give the corresponding bromohydrins in good yields, with high ee and de values. The cascade process is catalyzed by an ene-reductase and an alcohol dehydrogenase. Further manipulations of these bromohydrins, by two diastereodivergent routes, allowed the preparation of the tetrahydrofuran synthons. One route is based on a lipase catalyzed cleavage of the protecting group. The second route is characterized by a camphor sulfonic acid mediated isomerization of a β-hydroxyepoxide to give the tetrahydrofuran-2-ol. Finally, the synthesis of the most odorous and pleasant stereoisomer of the roasted meat aroma, i.e., (2S,3R)-2-methyl-3-thioacetate tetrahydrofuran, is reported as well.
A new practical method for the preparation of [3H6]-leukotrienes C4 and D4
Belley,Gareau,Zamboni,Ahern,Hong
, p. 599 - 609 (1995)
A new method for the synthesis of highly deuterated or tritiated leukotrienes was developed. The higher reactivity of a terminal alkene compared to a 1,2-disubstituted one permitted the selective deuteration or tritiation of the diyne 14,15,19,19,20,20-hexadehydro LTC4 triester 1. After hydrolysis. LTC4 was obtained in 36% overall yield. An average of seven deuterium or tritium atoms was incorporated and the specific activity of the tritiated LTC4 was greater than 180 Ci/mmol. 1 was obtained from the addition of glutathione to 14,15,19,19,20,20-hexadehydro LTA4 ethyl ester which was the product of a Wittig reaction between (3,8-nonanediyn-1-yl)triphenylphosphonium iodide and 5(S), 6(S), 7(E), 9(E) ethyl 5,6-epoxy-11-oxo-7,9-undecadienoate.
NbCl5-Mg reagent system in regio-and stereoselective synthesis of (2Z)-alkenylamines and (3Z)-alkenylols from substituted 2-alkynylamines and 3-alkynylols
Dzhemilev, Usein M.,Gabdullin, Azat M.,Kadikova, Rita N.,Mozgovoj, Oleg S.,Ramazanov, Ilfir R.
supporting information, (2021/07/02)
The reduction of N,N-disubstituted 2-alkynylamines and substituted 3-alkynylols using the NbCl5 –Mg reagent system affords the corresponding dideuterated (2Z)-alkenylamine and (3Z)-alkenylol derivatives in high yields in a regio-and stereoselective manner through the deuterolysis (or hydrolysis). The reaction of substituted propargylamines and homopropargylic alcohols with the in situ generated low-valent niobium complex (based on the reaction of NbCl5 with magnesium metal) is an efficient tool for the synthesis of allylamines and homoallylic alcohols bearing a 1,2-disubstituted double bond. It was found that the well-known approach for the reduction of alkynes based on the use of the TaCl5-Mg reagent system does not work for 2-alkynylamines and 3-alkynylols. Thus, this article reveals a difference in the behavior of two reagent systems—NbCl5-Mg and TaCl5-Mg, in relation to oxygen-and nitrogen-containing alkynes. A regio-and stereoselective method was developed for the synthesis of nitrogen-containing E-β-chlorovinyl sulfides based on the reaction of 2-alkynylamines with three equivalents of methanesulfonyl chloride in the presence of stoichiometric amounts of niobium(V) chloride and magnesium metal in toluene.
Catalytic Regio- and Enantioselective Oxytrifluoromethylthiolation of Aliphatic Internal Alkenes by Neighboring Group Assistance
Xu, Jia,Zhang, Yuanyuan,Qin, Tian,Zhao, Xiaodan
supporting information, p. 6384 - 6388 (2018/10/09)
Chiral selenide-catalyzed oxytrifluoromethylthiolation of aliphatic internal alkenes by a formally intermolecular strategy is disclosed, affording CF3S 1,3-amino alcohol and 1,3-diol derivatives with high regio-, enantio-, and diastereoselectivities. The reactions are promoted by a neighboring imide or ester group on substrates via a six-membered ring transition state. This assistance strategy is also successfully applied to the regio- and diastereoselective oxyhalofunctionalization of internal alkenes and the conversion of alkynes.
A containing halogen light active 2 - oxo - 1, 3 - oxazine compounds and its preparation method and application
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Paragraph 0095-0098, (2017/08/23)
The invention discloses a 2-carbonyl-1,3-oxazine compound and a preparation method therefor and application thereof. The structural formula of the 2-carbonyl-1,3-oxazine compound is shown in a formula II. The preparation method comprises: carrying out a reaction on a compound shown in a formula I and N-bromoacetamide (or 1,3-dibromo-5,5-dimethyl hydantoin) under the action of a scandium trifluoromethanesulfonate/monophosphine ligand. The photoactive 2-carbonyl-1,3-oxazine compound provided by the invention can be used for conveniently obtaining compounds containing 1,3-hydroxylamine structures and functionalized heterocyclic compounds through further conversion reactions, and meanwhile, a bromine atom can be introduced into the reaction. The functional groups can be further converted. Other functional groups are introduced, so that the compound has huge application value. According to the method provided by the invention, raw materials are easily synthesized, the reaction condition is mild, the operation is simple and convenient, the region selectivity is high, the enantioselectivty can reach up to over 99%, and the output reaches up to 72%. The formulae are shown in the description.
Chiral Selenide-Catalyzed Enantioselective Construction of Saturated Trifluoromethylthiolated Azaheterocycles
Luo, Jie,Liu, Yannan,Zhao, Xiaodan
supporting information, p. 3434 - 3437 (2017/07/15)
An indane-based, bifunctional, chiral selenide catalyst has been developed. The new catalyst is efficient for the enantioselective synthesis of saturated azaheterocycles possessing a trifluoromethylthio group. The desired products were obtained in good yields with high diastereo- and enantioselectivities.
Chemo- and Enantioselective Intramolecular Silver-Catalyzed Aziridinations
Ju, Minsoo,Weatherly, Cale D.,Guzei, Ilia A.,Schomaker, Jennifer M.
, p. 9944 - 9948 (2017/08/08)
Asymmetric nitrene-transfer reactions are a powerful tool for the preparation of enantioenriched amine building blocks. Reported herein are chemo- and enantioselective silver-catalyzed aminations which transform di- and trisubstituted homoallylic carbamates into [4.1.0]-carbamate-tethered aziridines in good yields and with ee values of up to 92 %. The effects of the substrate, silver counteranion, ligand, solvent, and temperature on both the chemoselectivity and ee value were explored. Stereochemical models were proposed to rationalize the observed absolute stereochemistry of the aziridines, which undergo nucleophilic ring opening to yield enantioenriched amines with no erosion in stereochemical integrity.
COMPLEX CATALYSTS BASED ON AMINO-PHOSPHINE LIGANDS FOR HYDROGENATION AND DEHYDROGENATION PROCESSES
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Page/Page column 38; 39, (2014/09/29)
The present application discloses novel PWNN and PWNWP metal catalysts for organic chemical syntheses including hydrogenation (reduction) of unsaturated compounds or dehydrogenation of substrates. The range of hydrogenation substrate compounds includes esters, lactones, enals, enones, enolates, oils and fats, resulting in alcohols, enols, diols, and triols as reaction products. The catalysts of current application can be used to catalyze a hydrogenation reaction under solvent free conditions. The present catalysts also allow the hydrogenation to proceed without added base, and it can be used in place of the conventional reduction methods employing hydrides of the main-group elements. Furthermore, the catalysts of the present application can catalyze a dehydrogenation reaction under homogenous and/or acceptorless conditions. As such, the catalysts provided herein can be useful in substantially reducing cost and improving the environmental profile of manufacturing processes for a variety of chemicals.
