Transition-metal-free three-component acetalation-pyridylation of alkenes via photoredox catalysis

A general transition-metal-free photoinduced acetalation-pyridylation of alkenes using diethoxyacetic acid and cyanopyridine was developed under mild conditions. By employing 4CzIPN as the photocatalyst and Cs2CO3 as the base, a diverse range of styrene derivatives and cyanopyridines worked well to give the desired products. The versatility of this method is highlighted by its application in the construction of various functional groups and the late-stage modification of drugs. Importantly, some of the synthesized compounds showed good in vitro antitumor activity, indicating that this protocol is of significance and potential for antitumor drug development.