Efficient rhodium-catalyzed Sommelet-Hauser type rearrangement of 3-diazoindolin-2-ones with a-thioesters has been accomplished for the synthesis of C4-thioalkylated oxindoles. The developed reaction offers the selective functionalization of C4-position of oxindole via generation of S-ylide and [2, 3]-sigmatropic rearrangement and allows access to diverse C4-thioalkylated oxindoles in good to excellent yield. Furthermore, the method was successfully extended to the synthesis C4-selenoalkylated oxindoles employingthe corresponding a-selenoester.
