A Lewis Base Catalysis Approach for the Photoredox Activation of Boronic Acids and Esters

26 Feb 2018

We report herein the use of a dual catalytic system comprising of a Lewis base catalyst such as quinuclidin-3-ol or 4- dimethylaminopyridine combined with a photoredox catalyst to generate carbon radicals from either boronic acids or esters. This system enabled a wide range of alkyl boronic esters and aryl or alkyl boronic acids to react via radical addition with electron-deficient olefins to efficiently form C–C coupled products in a redox neutral fashion. The Lewis base catalyst was shown to form a redox-active complex with either boronic esters or the trimeric form of the boronic acids (boroxines) in solution.