| Over the past several years, our group has been interested in the development of synthetically useful reactions that utilize visible light. By using transition metal complexes we have been able to generate a variety of reactive intermediates under exceptionally mild conditions. The research herein particularly describes the use of such an approach in the generation of free radicals. This includes the design of a photocatalytic reductive cyclization of enones that avoids the use of toxic tin reagents, and the development of a method for the addition of alpha-amino radicals across Michael acceptors. Understanding the mechanism of this transformation and taking advantage of the fact that transition metal photoredox catalysis and chiral Lewis acids are mutually compatible, we were able to develop a highly enantioselective variant of the conjugate addition of alpha-amino radical intermediates. |
