Asymmetric Synthesis of alpha-Quaternary gamma-Lactams through Palladium-Catalyzed Asymmetric Allylic Alkylation

摘要

The synthesis of chiral unsaturated gamma-lactams is reported featuring a highly enantioselective palladium-catalyzed asymmetric allylic alkylation of alpha,gamma-disubstituted 2-silyloxypyrroles. This method allows a straightforward access to optically active gamma-lactams bearing an alpha-quaternary stereogenic center in high yields (up to 93%), high regioselectivities (up to >20:1), and excellent enantioselectivities (up to 95% ee). To further demonstrate the synthetic utility of the method, the resulting allylated products were converted to various versatile chiral building blocks, such as pyrrolidines and pyrrolidinones.