Making bonds with copper and light

Abstract

Photochem. has had a rich history within the inorg. community, and there is broad current interest in using inorg. species to mediate photoinduced reactions that are important to reaction development. Some years ago our lab discovered a family of unusually emissive copper complexes featuring a combination of amide and phosphine ligands. This discovery led us to explore their efficacy in mediating Ullmann-type cross-coupling reactions, reasoning that a copper complex might play the role of both photoreductant to generate an org. radical R.bul. and also be a key reaction partner in a subsequent bond forming step, for example via the reaction of the liberated org. radical with a resulting copper(II)-amide to form an R-N bond. As we have explored the scope of this type of reactivity we have discovered an array of conditions/cocktails that mediate efficient photoinduced, Cu-mediated couplings under mild conditions, motivating us to try to understand what Cu-mediated mechanisms may be involved in these processes. In this talk I will provide an update of some of the key mechanistic questions we have addressd in the context of these C-X couplings mediated by copper and light.