Generation of stereodefined (Z)-3,4-dihydronaphthalen-1(2H)-ones via copper-catalyzed annulation-cyanotrifluoromethylation of 1,7-enynes

A new three-component strategy for the copper-catalyzed annulation–cyanotrifluoromethylation of easily available 1,7-enynes with Togni's reagent and TMSCN is developed. The reaction proceeds smoothly under mild conditions, providing a rapid and concise access to a wide range of stereodefined (Z)-3,4-dihydronaphthalen-1(2H)-ones with a quaternary carbon center in generally good yields. The protocol enjoys wide substrate scope regarding 1,7-enynes, high functional group tolerance and complete stereoselectivity.