Reversal Diastereoselectivity Between the Organomagnesium and Organolithium Reagents on Chiral <i>N</i>-<i>Tert</i>-Butylsulfinylaldimines for the Preparation of Chiral Amines
作者:Chinnapillai Rajendiran、Periyandi Nagarajan、A. Naidu、P. K. Dubey
DOI:10.1080/00397911.2014.909487
日期:2014.10.18
Abstract The asymmetric synthesis of both the enantiomer of chiral amines from the single chiral source of N-tert-butylsulfinylaldimines (3) by simply changing the organometallic reagents through diastereoselective addition. An efficient enantioselective synthesis of chiral amines including (S)-3-methyl-1-(2-piperidin-1-yl-phenyl)butyl amine (6a), a key intermediate to prepare antidiabetic drug repaglinide
Asymmetric synthesis of chiral amines by highly diastereoselective 1,2-additions of organometallic reagents to N-tert-butanesulfinyl imines
作者:Derek A. Cogan、Guangcheng Liu、Jonathan Ellman
DOI:10.1016/s0040-4020(99)00451-2
日期:1999.7
High yielding and highly diastereoselective methods for 1,2-additions of organometallic reagents to N-tert-butanesulfinyl aldimines (2) and N-tert-butanesulfinyl ketimines (3) are described. The additions of alkyl, aryl, alkenyl, and allyl carbanions to a diverse set of imines with different steric and electronic properties are demonstrated. Acidic methanolysis of the sulfinamide products (4 and 6)
Chiral quaternary benzophenone hydrazonium salt derivatives; Efficient chiral catalysts for the enantioselective phase-transfer alkylation of imines. Application to synthesis of chiral primary amines
作者:J.Jamal Eddine、M. Cherqaoui
DOI:10.1016/0957-4166(95)00149-j
日期:1995.6
(2S)-1-Methyl-1-[N-(diphenylmethylene)]-2-hydroxymethylpyrrolidine hydrazonium iodide I-a has been designed to catalyse the enantioselective phase-transfer alkylation of N-(diphenylmethylene) benzenemethanamine II. Although the weak acidic character of the latter, alkylations have been performed within reasonable reaction times. Optically active Primary amines III a-e have been prepared in good chemical yields and up to 94% e.e. using 2-5 mol-% of the chiral catalyst only.
Intermolecular Alkyl Radical Additions to Enantiopure <i>N</i>-<i>tert</i>-Butanesulfinyl Aldimines
作者:José A. Fernández-Salas、M. Carmen Maestro、M. Mercedes Rodríguez-Fernández、José L. García-Ruano、Inés Alonso
DOI:10.1021/ol400439g
日期:2013.4.5
The sulfinyl group In (R)-N-tert-butanesulfinyl aldimines provides efficient control of the stereoselectivity in the intermolecular reactions with alkyl radicals. The methodology is applicable to aryl, heteroaryl, benzyl, and alkynyl imines, even those containing CN, CO2Me, COR, and OH groups. The best results are attained with hindered radicals (tertiary and secondary ones) without C=N bond reduction. This reaction complements the well-established organometallic additions to N-sulfinyl aldimines to obtain enantiomerically pure functionalized a-branched primary amines.