Palladium(II)-Assisted Dialkylation and Alkylation/Acylation of Optically Active Ene Carbamates via Trialkylorganostannane Cross-Coupling and Carbonylative Coupling Processes

Alkylation of benzyl vinyl carbamate and propene with the anions of diethyl methylmalonate or dimethyl malonate in the presence of palladium(II) chloride, followed by cross-coupling or carbonylative cross-coupling with organostannanes, effected an overall dialkylation or alkylation/acylation of the monoolefin substrate. Complete control of stereochemistry in this palladium(II)-assisted reaction was observed using optically active ene carbamates affording β-amino-unsaturated keto esters in good chemical yields and excellent optical purity.