Rh-Catalyzed Conjugate Addition of Aryl and Alkenyl Boronic Acids to alpha-Methylene-beta-lactones: Stereoselective Synthesis of trans-3,4-Disubstituted beta-Lactones

摘要

A one-step preparation of 3,4-disubstituted beta-lactones through Rh-catalyzed conjugate addition of aryl or alkenyl boronic acids to alpha-methylene-beta-lactones is described. The operationally simple, stereoselective transformation provides a broad range of beta-lactones from individual alpha-methylene-beta-lactone templates. This methodology allowed for a direct, final-step C-3 diversification of nocardiolactone, an antimicrobial natural product.