Enantioselective C-H bond functionalization of aromatic ketones with 1,6-enynes photoredox/cobalt dual catalysis.

An enantioselective -C(sp)-H functionalization of ketones with 1,6-enynes is demonstrated photoredox/cobalt dual catalysis. The method exhibits high yields, functional group tolerance, and selectivity. Mechanistic studies suggested the operation of visible-light mediated low-valent cobalt complex generation, intramolecular cyclization, -C-H bond insertion, and reductive elimination as the key mechanistic steps.