Catalytic Direct Cyanomethylenation of C(sp)-H Bonds via a One-Step Double C-C Bond Formation.

An elegant and catalytic procedure for the one-step cyanomethylenation of C(sp)-H bonds adjacent to benzazoles and ketones is described herein using DMF as a C-1 unit and TMSCN as the cyanide source. The copper-mediated reaction between DMF and TMSCN gives a cyanomethylene radical intermediate that reacts with 2-alkylbenzazoles or alkylketones to furnish desired cyanomethylenated compounds under palladium catalysis. Subsequent interconversion of cyanomethylenated products makes the protocol synthetically attractive.