I2O5-Mediated 1,5-Cyclization of Aryldiynes with H2O: A Way To Access 3-Acyl-1-indenone Derivatives.

A facile I2O5-mediated 1,5-cyclization of aryldiynes with H2O has been successfully developed, leading to a broad range of substituted 3-acyl-1-indenones in moderate to excellent yields. The protocol has advantages of a metal-free process, mild reaction conditions, simple operation, and broad functional group tolerance. In the reaction, H2O is used as both a cosolvent and an oxygen source.