Exo/endo selectivity-control in Lewis-acid catalyzed tandem heterocyclization/formal [4 + 3] cycloaddition: synthesis of polyheterocycles from 2-(1-alkynyl)-2-alken-l-ones and 1,3-diphenylisobenzofuran

摘要

A novel catalytic exo/endo selectivity-controllable tandem heterocyclization/formal [4 + 3] cycloaddition was developed, which provides rapid, efficient and stereoselective access to highly fused polyheterocycles from readily available 2-(l-alkynyl)-2-alken-l-ones and 1,3-diphenylisobenzofuran under mild conditions. Polyheterocyclic structures are present in most natural and synthetic molecules with important biological activity.Therefore, the discovery of new efficient cyclization/cycloaddition reactions is important to access natural products and to explore a broad range of complex scaffolds with potentially enhanced bioactivity.