Three-Component Photochemical Cyclization/Dithiocarbamate Formation of -Difluoro Quinolin-2(1)-ones.

Herein, a novel visible-light-induced 6- difluoromethylation cyclization and subsequent carbo-thioesterification reaction is described. This protocol allows efficient access to valuable -difluoro quinolin-2(1)-ones in moderate to excellent yields under mild conditions. Broad amino sources compatibility, including cyclic morpholine, thiazolidine, thiomorpholine, pyrrolidine, 1,4-oxazepane, 2,6-dimethylmorpholine, -butyl piperazine-1-carboxylate and noncyclic diethylamine, -ethylpropan-1-amine, -benzylethanamine, -benzyl-trimethylsilanamine, dibenzylamine, and -(4-methoxybenzyl)ethanamine, demonstrated the practicability of this strategy. A radical-radical crossover route was proposed on the basis of radical inhibition experiments, visible light irradiation on-off test, apparent quantum efficiency (AQE) calculation, and fluorescence quenching studies.