Rh(II)/Pd(0) Dual Catalysis: Regiodivergent Transformations of Alkylic Oxonium Ylides

A Rh(II)/Pd(0) dual-catalysis strategy that promotes the regio-divergent transformations of alkylic oxonium ylides from α-diazo-β-ketoesters has been developed. Polyfunctionalized dihydrofuran-3-ones with an O-substituted quaternary carbon center and 2,3-disubstituted benzofurans can be selectively obtained in good to excellent yields at room temperature via one-pot synthesis. The reaction mechanism was further investigated by the control, stepwise, and crossover experiments.