Photocatalytic radical defluoroalkylation of unactivated alkenes via distal heteroarylipso-migration

Currently, the selective activation of C(sp(3))-F bonds and C-C bonds constitute one of the most widely used procedures for the synthesis of high-value products that range from pharmaceuticals to agrochemical applications. While numerous examples of these two methods have been reported in their respective fields, the processes which merge the activation of both single C(sp(3))-F bonds and C-C bonds in one step still remain elusive. Here, we demonstrate the controllable defluoroalkylation-distal functionalization of trifluoromethylarenes with unactivated alkenes via distal heteroaryl migration. This is proposed to proceed via tandem C(sp(3))-F and C-C bond cleavage using visible-light photoredox catalysis combined with Lewis acid activation. This strategy provides facile and flexible access to multiply functionalized alpha,alpha-difluorobenzylic ketones in useful yields (up to 88%) under mild conditions. The products can be further transformed into other valuable compounds, demonstrating the method's utility. The radical C-F cleavage of fluoroalkanes offers a valuable method for the synthesis of fluorinated products. Here, photoredox catalysis promotes tandem intermolecular defluoroalkylation/intramolecular heteroaryl migration of unactivated alkenes to yield difluorobenzyl ketones, proposed to proceed via a radical mechanism.