Photoinduced C–O bond cleavage for copper-catalyzed allenyl radical cyanation

The selective activation and transformation of C–O bonds under mild conditions is of great significance in synthetic chemistry because of the widespread existence of carbon–oxygen single bonds. In this work, allenyl radicals were generated by the photoinduced cleavage of carbon–oxygen bonds, and participated in the copper catalytic cycle, affording structurally diverse and highly significant allenyl nitriles. Both 1,3-disubstituted allenyl nitriles and trisubstituted allenyl nitriles could be assembled with moderate to good yields (24 examples, 65–95% yields) and high chemoselectivity. To prove the utility of this new methodology, an allene nitrile was converted into other valuable synthetic blocks including an allyl nitrile, alkyl nitrile and α-cyano cyclic ketone.