N-Sulfinyl Metalloenamine Conjugate Additions: Asymmetric Synthesis of Piperidines
摘要:
[GRAPHICS]The first examples of conjugate additions of N-tert-butanesulfinyl metalloenamines are reported. Highly stereoselective conjugate additions (97:3 to 99:1 dr) were observed between metalloenamines derived from N-sulfinyl ketimines and alpha,beta-unsaturated ketones bearing either alkyl or aryl substituents. The conjugate addition products could rapidly be converted with high diastereoselectivity to 2,4,6-trisubstituted piperidines, which are difficult to access by other methods.
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)