Acid-Catalyzed Addition of sp C-H Bonds to Olefins

摘要

The addition of terminal acetylenes to unsaturated bonds is a promising process to introduce an alkynyl group with 100% atom economy. Although some papers reported acetylene addition to C=C double bonds in the presence of transition metal catalysts, the substrates were usually limited to activated olefins such as 1,3-dienes, 1,3-enones, and norbornadienes.' On the other hand, as for the acid-catalyzed addition of terminal acetylenes to olefins, the only example reported to date used Zn(OTf)2, but the substrates were limited to highly reactive Meldrum's acid derivatives.