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Research has been conducted on the optically active propargylic alcohols. The reaction of the alpha-carbanion derived from 2-(trimethylsilyl)vinyl sulfoxides with aldehydes has been investigated and the results indicate that it produces diastereomeric product mixture.

New and excellent carbonyl-face selective reactions of 2-formyl- and 2-acylnaphthalenes bearing the bulky (2,3,6-triisopropylphenyl)sulfinyl group, which can be performed without isolation of the disastereomeric rotamers are described. The removal of the sulfinyl group from the products would provide a convenient and efficient method for preparation of the optically active 2-naphthylalkanols.

Chiral bis(oxazoline)s were used to achieve highly enantioselective reactions of configurationally labile alpha-thioorganolithiums.

Results reveal that p-tolyl alpha-lithio-beta-(trimethylsilyl)ethyl sulfoxide is a powerful chiral vinyl anion that is useful in the preparation of new chiral centers. Further, the p-tolyl alpha-lithio-beta-(trimethylsilyl)ethyl sulfoxide reacts with alpha,beta-unsaturated esters to form optically pure homoallylic carboxylates.

Research has been conducted on the reactions of alpha-sulfinyl carbanions with electrophiles. High stereoselectivity of the syn products of the reaction is discussed.

The catalytic enantioselective fluorobisphenylsulfonylmethylation of in situ generated imines from [alpha]-amido sulfones under the combination of Mannich-type conditions with 1-fluorobis(phenylsulfonyl)methane (FBSM) chemistry are described. Reductive desulfonylation is used for converting [alpha]-fluorobisphenylsulfonylmethylated amines to [alpha]-monofluoromethyl amines.

The enantioselective reaction of alpha-seleno carbanions derived from bis(phenylseleno)acetal and bis-(2-pyridylseleno)acetal in the presence of bis(oxazoline)s with various electrophiles gave products with high enantioselectivity. Mechanistic investigation reveals that the enantiodetermination of the reactions at -78 degree Celsius depends on dynamic thermodynamic resolution.

The study conducted to examine the enantioselective reaction of various alpha-lithiated dithioacetals with aldehydes or a ketone in the presence of bis(oxaline)s, is presented. With various aldehydes, an enantioselective reaction of a variety of lithiated dithioacetals is reported.

A peripherally substituted or unsubstituted phthalocyanines, having variety of metals is described by using a convenient synthesis. A novel synthesis of phthalocyanines directly from phtalimides and phthalic anhydride, by the action of hexamethyldisilazane (HMDS) under mild conditions, is reported.

Research has been conducted on p-tolyl 2-(trimethylsilyl)ethyl sulfoxide's alpha-carbanion. The reaction of this carbanion with esters and the following reduction with diisobutylaluminum hydride which produces highly stereoselective alpha-(trimethylsilyl)methyl-beta-ketosulfoxide is described.

The first example of catalytic enantioselective hydroxylation reaction of 2-oxindoles is described using the DBFOX-Zn(II) catalyst with oxaziridine as oxidant. The extension of the method to the Ni(II)-catalyzed enantioselective hydroxylation reaction of beta-keto esters using DBFOX ligand is also presented.

Thefirst catalytic enantioselective addition of hydroperoxidesto ketimines derived from isatins has been developed. Excellent yieldsand enantioselectivities were observed for the reaction of variousketimines with peroxides using a cinchona alkaloid sulfonamide catalyst.Both enantiomers of products could be obtained by using pseudoenantiomericchiral catalysts. The obtained product can be converted to opticallyactive α-amino hydroperoxide. [ABSTRACT FROM AUTHOR]

Highly enantioselectivedesymmetrization of aziridines with TMSNCShas been developed. Good yield and enantioselectivity were observedby using novel chiral imidazoline–phosphoric acid catalysts.The obtained product can be converted to a chiral β-aminothioland a β-aminosulfonic acid. [ABSTRACT FROM AUTHOR]

An organocatalytic enantioselective Mannich-type reaction of isocyanoacetate with N-sulfonylimines catalyzed by chiral thioureas derived from quinine yielded 2-imidazolines with high diastereo- and enantioselectivities (up to >99:1 dr. and 96% ee). This reaction provided a convenient route to access various imidazolines and related α,β-diamino acids having a quaternary carbon center in high enantiomeric purities. [ABSTRACT FROM AUTHOR]

The enantioselective reaction of α-seleno carbanions derived from bis(phenylseleno)acetal and bis(2-pyridylseleno)acetal in the presence of bis(oxazoline)s with various electrophiles gave products with high enantioselectivity. The enantioselective reaction of α-lithio benzyl 2-pyridyl selenide gave the products with stereochemistry reverse to that obtained in the reaction of α-lithio benzyl phenyl selenide. Mechanistic investigation suggests the enantiodetermination of these reactions at -78 °C depends on dynamic thermodynamic resolution. The enantioselective reaction was applied to the preparation of enantioenriched olefins and epoxide. [ABSTRACT FROM AUTHOR]

The enantioselective reaction of various α-lithiated dithioacetals with aldehydes or a ketone in the presence of bis(oxazoline)s was examined. Among them, unsymmetrical dithioacetals were found to be the best choice for attaining high enantioselectivity. The reaction of lithiated tert-butylthio(2-pyridylthio)methane with aldehydes proceeded with good diastereoselectivity as well as with good enantioselectivity. The enantioselective reaction was shown to proceed through dynamic thermodynamic resolution. Mercury(II) chloride effected hydrolysis of the dithioacetal moiety of the products to 2-hydroxyaldehydes, which were directly reduced to give the optically active 1,2diols. [ABSTRACT FROM AUTHOR]

The reaction of the α-carbanion of p-tolyl 2-(trimethylsilyl)ethyl sulfoxide with esters followed by reduction with DIBAL gave α-(trimethylsilyl)methyl-β-hydroxysulfoxides with high stereoselectivity. The stereoselective reaction was demonstrated to proceed through a dynamic kinetic resolution pathway via a six-membered cyclic transition state involving Si-O interaction. These reactions provide a convenient route for the synthesis of optically pure allylic alcohols. [ABSTRACT FROM AUTHOR]

The article focuses on a research about the first catalytic enantioselective hydrophosphonylation of ketimines using cinchona alkaloids and a base. It states that 10 mol % catalyst loading of cinchona alkaloids as well as K2CO3 was used to determine enantioselective hydrophosphonylation reaction of ketimines. It notes that performing the reaction at -20 °C improved enantioselectivity. Results show that using cinchona alkaloids allows direct access to enantiomers.

The article describes the first example of catalytic enantioselective hydroxylation reaction of 2-oxindoles 1 using DBFOX—ZN(II) catalyst with oxazirdine 3 as oxidant. The researchers tested other substrates such as β-keto esters to demonstrate the further synthetic utility of DBFOX-catalyzed hydroxylation system. They concluded that the structure of oxaziridine 3 was found to play an important role to increase the enantioselectivity.

This article discusses various issues related to cinchona alkaloid and sulfinyl chloride combinations. Chiral sulfinates play an important role in organic chemistry as key precursors in many chiral sulfoxides that are useful building blocks for biologically active molecules and natural products. Despite the development of many synthetic strategies to access chiral sulfinates in the last two decades, the most industrially viable procedure is still the one based on the resolution of diastereomeric sulfinates prepared from sulfinyl halides and chiral alcohols such as menthol. The article authors report on a novel approach to the asymmetric sulfinylation reaction based on a cinchona alkaloid sulfinyl chloride combination that acts as the first asymmetric sulfinylating agents of achiral alcohols.

Chiral phosphine-containing amino acids are useful motifs in pharmaceutical compounds. In this study, we developed the asymmetric conjugate addition of phosphine sulfides with α-substituted β-nitroacrylates to synthesize phosphine-containing amino acid precursors with chiral tetrasubstituted carbon centers. This method showed a wide substrate scope, and the obtained products were converted into various chiral compounds. The origin of the enantioselectivity was clarified by computational analysis.

The enantioselective reaction of α-substituted β-nitroacrylates with oxazol-5-(4 H )-ones (oxazolones) to construct consecutive tetrasubstituted stereogenic centers was accomplished. A cinchona alkaloid sulfonamide catalyst afforded products bearing vicinal chiral centers with excellent enantio- and diastereoselectivities. The obtained products were successively converted into various chiral compounds without loss of their enantiopurity. Furthermore, density functional theory (DFT) calculations were performed to elucidate the mechanism and origin of the observed stereoselectivity of the reaction.

The first enantioselective Pictet-Spengler reaction of acyclic α-ketoesters with tryptamines has been developed. Excellent yields and enantioselectivity were obtained for the reaction using chiral imidazoline-phosphoric acid catalysts. Density functional theory calculations suggested possible transition states that explain the origin of chiral induction. This process provides an efficient route for the synthesis of tetrahydro-β-carboline derivatives.

The enantioselective reaction of 2 H -azirines with oxazol-5-(4 H )-ones (oxazolones) using a cinchona alkaloid sulfonamide catalyst has been developed. The reaction proceeded at the C-2 position of oxazolones to afford products with consecutive tetrasubstituted stereogenic centers in high yield with high diastereo- and enantioselectivity. The obtained aziridines were converted into various chiral compounds without loss of enantiopurity.

The enantioselective vinylogous Mannich reaction of ketimines derived from isatins with acyclic vinylketene silyl acetals has been developed using a chiral bis(imidazoline)-Cu(II) catalyst. A series of chiral 3-aminooxindole derivatives bearing tetra-substituted stereogenic centers with an α,β-unsaturated ester moiety were obtained in excellent yields (up to 99%) with high enantioselectivities (up to 98% ee). Enantioselective bisvinylogous Mannich reaction to ketimines derived from isatins also afforded product with high enantioselectivity. Based on the experimental investigations, a possible transition state has been proposed to explain the origin of the asymmetric induction.

The first catalytic enantioselective reaction of 2H-azirines with thiols has been developed. The obtained aziridines can be converted to optically active oxazolines, aziridylamides, or α-sulfonyl esters. Transformation of these optically active aziridines showed that 2H-azirines act as β,β-dicarbocationic amine synthons.

The enantioselective oxidative ring-opening reaction of aziridines with α-nitroacetates has been developed. Good yields and enantioselectivity were observed for the reaction of various aziridines using a novel cinchona alkaloid amide/NiBr 2 catalyst. Both enantiomers of products could be obtained by using pseudoenantiomeric chiral catalysts. This process offers an efficient route for the synthesis of α-aminoketones.

The first catalytic enantioselective addition of thiols to ketimines derived from isatins has been developed. Excellent yields and enantioselectivities were observed for the reaction of various ketimines and thiols using a cinchona alkaloid sulfonamide catalyst. Both enantiomers of products could be obtained by using pseudoenantiomeric chiral catalysts.

Enantiomerically enriched trihalomethyl-substituted alcohols having a quaternary chiral carbon center can be prepared by the catalytic enantioselective cross-aldol reaction of acetone with trihalomethyl ketones by using N-(8-quinolinesulfonyl)prolinamide as an organocatalyst. The MO calculations elucidate that the hydrogen bonding between the sulfonimide proton and the 8-quinolyl nitrogen atom plays an important role in exerting the enantioselectivity of the reaction.

The catalytic, nucleophilic enantioselective trifluoromethylation reaction of both acyclic and cyclic aryl ketones using the Ruppert-Prakash reagent is now at hand, with an operationally simple procedure, based on the combination of ammonium bromide of cinchona alkaloids with TMAF. The procedure is reliable and general. Trifluoromethyl-substituted tetrasubstituted aryl alcohols have been synthesized in up to 94% ee.