Palladium/Silver-Cocatalyzed Tandem Reactions of Oxabenzonorbornadienes with Substituted Arylacetylenes: A Simple Method for the Preparation of 1,2-Diarylethanones and 1,2-Diary Diarylacetylenes

The effective synthesis of 1,2-diarylethanones was achieved using palladium(II) acetate [Pd(OAc)(2)] and silver triflate (AgOTf) as cocatalysts from various oxabenzo-norbomadiene derivatives and substituted arylacetylenes via tandem reactions under mild conditions. Exploration of the oxabenzonorbomadiene substrates showed that the 1,2-diarylacetylenes were obtained from adjacent alkoxy substituted oxabenzonorbornadiene derivatives. Preliminary mechanistic studies indicate that the AgOTf served as an indispensable catalyst, and the mechanism of the tandem reaction was proposed.