Pd-Cu bimetallic catalyzed domino cyclization of alpha-allenols followed by a coupling reaction: new sequence leading to functionalized spirolactams

Chemistry. 2005 Sep 19;11(19):5708-12. doi: 10.1002/chem.200500228.

Abstract

A novel regioselective metal-catalyzed spirocyclization of alpha-allenols-cross coupling (Heck, Sonogashira, and Suzuki) reaction sequence, leading to potentially bioactive spirocyclic lactam derivatives has been developed. Precursors for the tandem spirocyclization-coupling reaction, alpha-allenols 2 a-d were obtained starting from alpha-oxolactams 1 a-c via indium-mediated Barbier-type carbonyl-allenylation reaction in aqueous media by using our previously described methodologies.