Palladium-catalysed asymmetric allylations by a chiral allyl ester; the palladium catalysis of (S)-proline allyl ester enamines
Abstract
The palladium-catalysed allylation of the chiral enamines (1a–d) followed by acidic hydrolysis, produced optically active 2-allylcyclohexanone (2); the catalysis of the chiral enamine (1a), derived from (S)-proline allyl ester, with tetrakis(triphenyl phosphine)palladium and subsequent acidic hydrolysis led to an almost 100% optical yield of (S)-(–)-(2).