Rhodium-catalyzed asymmetric arylation of α,β-unsaturated imines with arylstannanes.: Catalytic asymmetric synthesis of allylic amines

Catalytic asymmetric arylation of N-alkylidenesulfonamides 1a-d, which are prepared from alpha,beta -unsaturated aldehydes and 4-nitrobenzenesulfonamide, with aryltrimethylstannanes 2m-p proceeded in the presence of 3 mol% of a rhodium catalyst coordinated with (R)-MOP ligand in dioxane at 110 degreesC to give sulfonamide of allylic amines (R)-3 with high enantioselectivity (up to 96% eel in high yields. Some of the allylic amines were converted in to the sulfonamide of (S)-phenylglycine without loss of enantiomeric purity by oxidative cleavage of the carbon-carbon double bond. (C) 2001 Elsevier Science Ltd. All rights reserved.