Synthesis of Sterically Hindered α-Hydroxycarbonyls through Radical–Radical Coupling
Kenji Ota, Kazunori Nagao, Hirohisa Ohmiya
Abstract
We describe a synthetic approach to sterically hindered α-hydroxy carbonyl compounds through radical-radical coupling. An organic photoredox catalysis reaction converts an aliphatic carboxylic acid and α-ketocarbonyl to a transient alkyl radical and a persistent ketyl radical, respectively, which couple selectively based on the persistent radical effect. This protocol allows the use of primary, secondary, and tertiary aliphatic carboxylic acids to introduce various alkyl substituents onto ketone moieties of α-ketocarbonyls under mild reaction conditions.
Topics & Concepts
ChemistryKetylSteric effectsAlkylKetoneRadical cyclizationRadicalPhotochemistryCatalysisRadical disproportionationCoupling reactionPrimary (astronomy)Carboxylic acidPhotoredox catalysisOrganic chemistryPhotocatalysisDisproportionationAstronomyPhysicsRadical Photochemical ReactionsCatalytic C–H Functionalization MethodsSulfur-Based Synthesis Techniques