Synthesis of the Azaphilones Using Copper-Mediated Enantioselective Oxidative Dearomatization

摘要

The azaphilones are a structurally diverse family of natural products containing a highly oxygenated bicyclic core and chiral quaternary center (cf.S-15183a,1,Figure 1).We recently reported the synthesis of (+-)-l and several unnatural azaphilones employing gold(III)-catalyzed cycloisomerization of o-alkynylbenzaldehydes to 2-benzopyrylium salts and subsequent I(V)-mediated oxidation.In addition to our studies,a number of synthetic efforts have been reported toward the racemic synthesis of the azaphilones with only a single report regarding asymmetric control of the quaternary center.