Photo-Enabled Synthesis of Carbon–Nitrogen and Remote Carbon–Carbon Bonds

Abstract

<p>Recent advances in photo-driven reactions have dramatically expanded thescope of transformations no longer exclusively dependent on thermal energy to drive cross-coupling activity of transition metal catalysts. Of these catalysts, nickel has emerged as one of the most versatile due, in part, to its flexibility in adopting all integer oxidation states from 0 to +4, as well as its lower cost and higher abundance in comparison to precious metal catalysts. Carbon–heteroatom and carbon–carbon cross-couplings are areas of particularly resurgent expansion in photo-driven reaction development. These classes of couplings are essential in the production of innumerable compounds including fine chemicals and natural product synthesis, as well as pharmaceuticals and agrochemicals. Disclosed herein are investigations into dual photo-/nickel-catalyzed reactions for C–N and C–C cross-coupling with (hetero)aryl bromides in sulfamides and sulfamate esters, respectively. The reactivity demonstrated in the N-(hetero)arylation of sulfamides is complementary to that previously demonstrated in traditional, palladium-catalyzed processes. Moreover, the radical C(sp2)–C(sp3) cross-coupling guided by a 1,6-HAT process in sulfamate esters is the first example of this type of nickel-/photocatalyzed reaction and has been long sought after by pioneers of the field. This represents the first plank in a new platform for internally guided, nickel-catalyzed cross-coupling reactions. The development of these complementary technologies constitutes a substantive advancement in access to chemically diverse sulfamides and C–H functionalization technologies, respectively.</p>