Multiple Aryne Insertions into Oxindoles: Synthesis of Bioactive 3,3-Diarylated Oxindoles and Dibenzo[b,e]azepin-6-ones.

An aryne insertion cascade reaction on oxindoles has been observed and constitutes a convenient "one pot" preparation of bioactive di- and triarylated oxindoles in good yields under mild conditions. A temperature controlled "reaction switch" enables ready access to dibenzo[b,e]azepin-6-one derivatives employing the same reaction regime. This tactic has been extended to a short synthesis of potent antiulcer agent darenzepine.