Photoinduced Cobalt Catalyzed Radical Heck-Type Reaction of Alkyl Electrophiles

Photoinduced cobalt catalyzed site selective alkylation of 2-pyridones

“…Encouraged by these photoinduced cobalt-catalyzed alkylation reactions 17 and by our previous work, 18 we proposed a novel alkylating strategy for site-selective alkylation on the 2-pyridone ring. This protocol was based on visible light-promoted cobalt-catalyzed alkyl halide reactions to generate alkyl radicals, followed by selective radical addition reactions to 2-pyridones.…”

“…Initially, cobalt cobaloxime( iii ) ( Co-I ) is transferred to a cobalt hydrogen species A upon treatment with NaBH 4 . 18 In the presence of a base, nucleophilic cobaloxime( i ) B is generated which then reacts with alkyl halides or pseudo halides via nucleophilic substitution to generate a new alkyl cobalt species C . Light-induced homolytic Co–C bond cleavage of C results in the formation of the alkyl radical D and the production of the Co( ii ) intermediate F .…”