MeOTf-Induced Carboannulation of Isothiocyanates and Aryl Alkynes with C═S Bond Cleavage: Access to Indenones.

MeOTf-induced carboannulation of alkyl isothiocyanates and aryl alkynes for the synthesis of indenones in good yields under metal-free conditions with C═S bond cleavage is described. The thioalkoxy group at the 3-position of the indenone can also be converted into other functional groups, such as phenyl, methylsulfonyl, amino, and ethoxy groups.