Synthesis of 3,3-dialkyl-substituted isochroman-1,4-diones via copper/photoredox dual-catalyzed carbolactonization of alkenes

Abstract

We report a general and concise method for modular synthesis of various 3,3-dialkyl-substituted isochroman-1,4-diones via copper/photoredox dual-catalyzed carbolactonization of alkenoic acids with NHPI esters. A diverse range of NHPI esters derived from natural products and marketed drugs are successfully compatible with this reaction. With this approach, various alkyl-substituted isochroman-1,4-diones featuring a quaternary carbon center at the α-position of the carbonyl group can be synthesized in good to excellent yields.