Visible-light-induced photocatalyst-free activation of alkynyl triflones for trifluoromethylalkynylation of unactivated 1,6-dialkenes

A visible-light-induced trifluoromethylalkynylation of 1,6-dialkenes was developed under transition-metal-free and photocatalyst-free conditions, enabling the construction of three C-C bonds in a single preparation step. By employing a catalytic amount of benzoyl peroxide (BPO) as an initiator, this protocol enables easy-to-handle activation of alkynyl triflones under photocatalyst-free conditions for the first time to initiate a photocatalytic radical cascade cyclization reaction, showing obvious advantages of high step-economy, mild reaction conditions, and broad substrate scope.