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 α,β-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°C to give sulfonamide of allylic amines (R)-3 with high enantioselectivity (up to 96% ee) 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.