Transition-metal catalyzed oxidative spirocyclization of -aryl alkynamides with methylarenes under microwave irradiation.

A practical synthetic route to construct a variety of 3-benzyl spiro[4,5]trienones was developed transition-metal Cu/Ag-catalyzed oxidative -annulation of activated alkynes with unactivated toluenes using TBPB as an oxidant under microwave irradiation. This method allows the formation of two carbon-carbon bonds and one carbon-oxygen bond in a single reaction through a sequence of C-H oxidative coupling, -carbocyclization and dearomatization. The advantages of this protocol are its operational simplicity and broad substrate scope, and the ability to afford the desired products in moderate to good yields.