Enantioselective Synthesis of an Indenopyrrole Scaffold Containing an All-Carbon Quaternary Stereocenter via a Visible-Light-Mediated Organocatalytic Carbene Transfer Reaction.

The organocatalytic photochemical carbene transfer reactions remain in early stages of development and confront numerous challenges. Herein, we report the first visible-light-mediated organocatalytic strategy for the enantioselective synthesis of indeno[1,2-c]pyrroles bearing an all-carbon quaternary stereocenter with excellent enantioselectivities by the reaction of diazo arylidene succinimides with α,β-unsaturated ketones. This work represents the first carbene transfer reaction of diazo arylidene succinimides and a cinchona alkaloid-derived catalyst in photochemical asymmetric transformation.