Isocyanide-Based Multicomponent Bicyclization with Substituted Allenoate and Isatin: Synthesis of Unusual Spirooxindole Containing [5.5]-Fused Heterocycle.

A three-component bicyclization reaction of isocyanide, substituted allenoate, and isatin has been disclosed. This protocol is proposed to proceed through Michael addition, double cyclization, and [1,5]-hydride shift sequence, thus leading to the formation of two new rings and five new chemical bonds, including C-C, C-O, and C-N bonds.