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

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. [ABSTRACT FROM AUTHOR]