Enantioselective Photocatalytic [3 + 2] Cycloadditions of Aryl Cyclopropyl Ketones

摘要

Control of stereochemistry in photocy-cloaddition reactions remains a substantial challenge; almost all successful catalytic examples to date have involved [2 + 2] photocycloadditions of enones. We report a method for the asymmetric [3 + 2] photocycloaddition of aryl cydopropyl ketones that enables the enantiocon-trolled construction of densely substituted cydopentane structures not synthetically accessible using other catalytic methods. These results show that the dual-catalyst strategy developed in our laboratory broadens synthetic chemists' access to dasses of photochemical cycloadditions that have not previously been feasible in enantioselective form.