Visible-Light-Induced Monofluoroalkenylation and -Difluoroallylation of Inactivated C(sp)-H Bonds via 1,5-Hydrogen Atom Transfer (HAT).

The direct monofluoroalkenylation of C(sp)-H bonds is of great importance and quite challenging. Current methods have been restricted to the monofluoroalkenylation of activated C(sp)-H bonds. Here, we reported the photocatalyzed C(sp)-H monofluoroalkenylation of inactivated C(sp)-H bonds with -difluoroalkenes via 1,5-hydrogen atom transfer.

Oxalates as Activating Groups for Tertiary Alcohols in Photoredox-Catalyzed -Difluoroallylation To Construct All-Carbon Quaternary Centers.

Construction of challenging and important all-carbon quaternary centers has received growing attention. Herein, with oxalates as activating groups for tertiary alcohols, we report photoredox-catalyzed -difluoroallylation to construct all-carbon quaternary centers enabled by efficient tertiary radical addition to α-trifluoromethyl alkenes. This transformation shows good functional group tolerance for both α-trifluoromethyl alkenes and oxalates.

Recent advances in difunctionalization of alkenes using pyridinium salts as radical precursors.

In this review, we summarise the recent applications of pyridinium salts in the radical-mediated difunctionalization of alkenes. Pyridinium salts are a privileged class of compounds that show great utility in natural products and synthetic chemistry. Various organic transformations of pyridinium salts, especially in radical chemistry, have been developed in recent years.