Atom Transfer Radical Addition using Photoredox Catalysis

Abstract

Utilizing visible light-mediated catalysts as initiators, the atom transfer radical addition (ATRA) protocol can be performed under mild reaction conditions, have minimal side reactions, and operate with optimal catalytic efficiency and straightforward purification. Although ATRA reactions allow for efficient difunctionalization of alkenes or alkynes, most methods unfortunately employ harsh reaction conditions and/or toxic reagents and lack broad functional group tolerance. Given the propensity for photoredox catalysis to initiate radical reactions, it was the natural choice for the further development of ATRA reactions toward obviating the shortcomings discussed in this chapter. With the reinvigoration of photoredox catalysis and its proclivity to initiate radical reactions it allowed for the development of ATRA as a more accessible tool. ATRA is a highly atom-economical process and through the use of photoredox catalysis has become a much milder method giving it the potential for use in natural product synthesis or for potential pharmaceuticals.