Photoredox-Catalysed Desulfinylative Cross-Couplings to Access Benzylic Alcohol and Amine Derivatives

Benzylic alcohols and amines (and their derivatives) are rife in bioactive molecules. They are especially prevalent in agrochemicals where they form key structural components of many herbicides, fungicides and insecticides. Typical routes to access these functionalities involve C-O or C-N bond formation via substitution reactions with benzylic precursors. These benzylic precursors, however, are generally formed through a two-step acylation/reduction sequence from aryl halides, resulting overall in a multistep process that is unsuitable for library synthesis. The aim of this project is to develop a novel C(sp2)-C(sp3) cross-coupling of aryl halides with alpha-oxy or alpha-amino carbon-centred nucleophiles. This is intended to be achieved via a metallaphotoredox-mediated oxidative desulfinylation of alpha-oxy or alpha-amino sulfinates, which could be generated in situ from aldehydes/ketones (to access benzylic alcohols) or imines (to access benzylic amines). The simple in situ generation of these sulfinate intermediates from a variety of aldehydes, ketones or imines will provide a significant advantage over related cross-couplings due to the ease of synthesis and greater structural diversity of the coupling partners, leading to a broader substrate scope.