Visible light/Ir(III) photocatalytic initiation of xanthate-based radical-chain reactions: Xanthate group transfer and oxidative addition to aromatic systems

A photocatalyzed redox generation of radicals from O-ethyl xanthates to generate electrophilic radicals under photoredox catalysis, using Ir(ppy)₃ and blue LEDs irradiation is described. The protocol can be used in classical xanthate-based inter- and intra-molecular group transfer reactions and oxidative radical addition to several heteroaromatic systems. The process does not require high temperature and reactions are cleaner compared with the traditional peroxide initiation. In the oxidative addition to aromatic systems, the oxidation process is part of the catalytic cycle and does not require a stoichiometric oxidant such as DLP which is particularly difficult to separate from the product.