Organophotocatalytic Regioselective Silylation/Germylation and Cascade Cyclization of -Alkenyl α-CF Acrylamides: Access to Densely Functionalized 4-Pyrrolin-2-ones.

We report an organophotoredox-catalyzed silylation/germylation cascade cyclization of -alkenyl α-CF acrylamides under mild conditions. -Aminopyridinium salts act as hydrogen atom transfer reagents under photoredox catalysis in the generation of silyl and germyl radicals. An array of silyl- and germyl-substituted 3-CF-4-pyrrolin-2-one derivatives were constructed in a shorter reaction time with low catalyst loading in good to excellent yields at room temperature. Importantly, this protocol is amenable to the late-stage diversification of bioactive molecules, as well as to large-scale synthesis.