Stille coupling of stereochemically defined alpha-sulfonamidoorganostannanes.
Addition of tributylstannylmetallics to (R)-tert-butanesulfonimine derivatives of arylaldehydes provides alpha-sulfinamidostannanes with high (>98% de) diastereoselectivities. Oxidation of these compounds with m-CPBA gives alpha-sulfonamidostannanes which undergo Pd/Cu-catalyzed Stille-type couplings with benzoyl chloride. Best yields are achieved using the electron-rich tris(2,4,6-trimethoxyphenyl)phosphine as the ligand. Inversion of configuration at the benzylic carbon is observed.
Kells
Kevin W
KW
Guelph-Waterloo Centre for Graduate Work in Chemistry and Biochemistry, Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1.
Chong
J Michael
JM