AN IMPROVED ASYMMETRIC SYNTHESIS OF ALPHA-BRANCHED CHIRAL AMINES

摘要

The present invention relates to an improved asymmetric synthesis of alpha- branched amines (hereafter referred to as the compound (1)) and relative chiral amines (1'') or its pharmaceutically acceptable salt and derivatives. The process comprises an unusual substrate specific regioselective ortho lithiation of substituted arene compounds, followed by its highly diastereoselective addition to N-tert-butanesulfinylimines resulting in the selective formation of alpha-branched sulfinyl amine (4) and chiral amine (6); which on subsequently removing the sulfinyl group provides corresponding alpha-branched amines (1) or relative chiral amines (1'').