Practical and highly stereoselective method for the preparation of several chiral arylsulfinamides and arylsulfinates based on the spontaneous crystallization of diastereomerically pure N-benzyl-N-(1-phenylethyl)-arylsulfinamides
摘要:
A novel and simple process for the preparation of enantiomerically pure (S(s))-benzenesulfinamide (S(s))-3a, (S(s))-p-toluenesulfinamide (S(s))-3b, (S(s))-p-chloro-benzenesulfinamide (S(s))-3c and (S(s))-p-fluorobenzenesulfinamide (S(s))-3d has been developed. The treatment of arylsulfinyl chlorides with (R)-N-benzyl-1-phenylethanamine in the presence of excess triethylamine gave diastereomeric mixtures of N-benzyl-N-(1-phenylethyl)-arylsulfinamides 1, which underwent spontaneous crystallization to furnish diastereomerically pure (R,S(s))-N-benzyl-N-(1-phenylethyl)-arylsulfinamides (R,S(s))-1a-1d in 28%, 29%, 27% and 31% yields, respectively. The diastereomerically pure compounds (R,S(s))-1 were then converted into four enantiopure (R(s))-methyl arylsulfinates (R(s))-2, and finally into four enantiopure (S(s))-arylsulfinamides (S(s))-3 in good yields. (C) 2011 Elsevier Ltd. All rights reserved.
Treatment of sulphinamides with alcohols in the presence of strong acids results in the formation of sulphinates in good yields; this reaction has been shown to proceed with inversion of configuration at the sulphinyl centre and high stereospecificity which is dependent on the structure of the alcohol used.
Acid Catalyzed Alcoholysis of Sulfinamides: Unusual Stereochemistry, Kinetics and a Question of Mechanism Involving Sulfurane Intermediates and Their Pseudorotation
formed in this reaction with a full or predominant inversion of configuration at chiral sulfur or with predominant retention of configuration. The steric course of the reaction depends mainly on the size of the dialkylamido group in the sulfinamides and of the alcohols used as nucleophilic reagents. It has been found that bulky reaction components preferentially form sulfinates with retention of configuration
Asymmetric synthesis of chiral organosulfur compounds using N-sulfinyloxazolidinones
作者:David A. Evans、Margaret M. Faul、Lino Colombo、John J. Bisaha、Jon Clardy、David Cherry
DOI:10.1021/ja00041a011
日期:1992.7
which may be readily purified by chro- matography. These sulfinylating agents react with a wide range of nucleophiles such as Grignard reagents, enolates, lithium alkoxides, or metalated amides, with inversion of configuration at the sulfur center to afford the derived chiral sulfoxides, sulfinate esters, and sulfinamides in high yields and enantioselectivities. Competition experiments have established
The optical rotation, electronic circular dichroism (ECD) and vibrational circular dichroism (VCD) of chiral sulfinates have been studied experimentally, and analysed by density functional theory calculation, aiming at establishing a reliable and convenient methodology to determine their absoluteconfiguration. Through the study on a model chiral sulfinate with known absoluteconfiguration, (R)-(+)-methyl
Studies on Chiral Organosulfur Compounds. VI. The Use of a Chiral Diene Bearing an Optically Active Sulfinylmethyl Group in the Lewis Acid-Catalyzed Intramolecular Asymmetric Hetero Diels-Alder Reaction.
An asymmetric Diels-Alder reaction with a diene bearing a chiral sulfinyl group is described. The Lewis acid-catalyzed intramolecular asymmetric hetero Diels-Alder reaction of a chiral α'-sulfinyl-α, β-unsaturated ketone derived from 3-methylcitronellal produced optically active 4a, 5, 6, 7, 8, 8a-hexahydro-1H-2-benzopyran derivatives. On the basis of the stereochemical results obtained, a plausible mechanism for the asymmetric induction is presented.