DBU-Catalyzed Vinylogous Reaction of 3-Cyano-4-methylcoumarins with 3-Arylsulfonyl-3-indolyloxindoles

Abstract

An efficient metal-free DBU catalyzed approach for the construction of biologically significant quaternary carbon centered C-3 functionalized 2-oxindole derivatives through vinylogous reaction of 3-cyano-4-methylcoumarins with 3-arylsulfonyl-3-indolyloxindoles has been developed for first time. The developed protocol is simple, cost-effective, and producing the desired products in good yields, without utilizing potentially harmful chemicals. Moreover, the synthesized 3,3-disubstituted 2-oxindole molecules contain established pharmacophors in their structure, i. e., oxindole-, indole- and coumarin- moieties, which makes them a valuable candidate for drug development process.