Rhodium/Lewis Acid Catalyzed Regioselective Addition of 1,3-Dicarbonyl Compounds to Internal Alkynes

Herein we describe an efficient protocol for the regioselective addition of 1,3-dicarbonyl compounds to internal alkynes catalyzed by rhodium/Lewis acid catalysts. The corresponding branched/linear allylic alkylation products could be selectively obtained in good yields. Rh–H species were considered to be generated by direct C–H oxidative addition of 1,3-dicarbonyl compounds with rhodium catalyst with the assistance of Lewis acid. Moreover, a retro-allylic alkylation process was observed in this transformation.