Total Synthesis of Boletopsin 11 Enabled by Directed ortho-C(sp2)–H Arylation

摘要

A nine-step synthesis of boletopsin 11 (1 ), a bioactive fungal natural product, is disclosed. Key features include a one-pot [O]-oxa-Michael cascade to establish the polyoxygenated dibenzofuran core followed by a Pd-catalyzed directed ortho -C(sp~(2))–H arylation to complete the fully functionalized carbon skeleton. Exploration of the latter transformation led to the discovery of an unexpected tandem ortho -C(sp~(2))–H arylation event, and the scope of the directed ortho -C(sp~(2))–H reaction was further investigated with coupling partners varying in stereoelectronic properties.