Photocatalytic Trifluoromethyl Carbyne Equivalent Generation: A Modular Platform for Cascade Cycloannulation

-aryl acrylamides with trifluoromethyl carbyne equivalents is described, affording structurally diverse trifluoromethylated oxindoles bearing a diazo moiety. This first carbyne-equivalent-mediated radical cascade reaction proceeds through a diazotrifluoroethyl radical intermediate, exhibiting broad substrate scope, excellent functional group tolerance, and high regioselectivity. Mechanistic investigations support a radical mechanism involving a reductive quenching cycle. Gram-scale synthesis and product derivatizations demonstrate the synthetic utility, establishing a new platform for both fluorinated heterocycle synthesis and carbyne chemistry.