Isothiourea‐Catalysed Acylative Kinetic Resolution of Aryl–Alkenyl (sp² vs. sp²) Substituted Secondary Alcohols

Abstract

The non-enzymatic acylative kinetic resolution of challenging aryl-alkenyl (sp² vs. sp² ) substituted secondary alcohols is described, with effective enantiodiscrimination achieved using the isothiourea organocatalyst HyperBTM (1 mol %) and isobutyric anhydride. The kinetic resolution of a wide range of aryl-alkenyl substituted alcohols has been evaluated, with either electron-rich or naphthyl aryl substituents in combination with an unsubstituted vinyl substituent providing the highest selectivity (S=2-1980). The use of this protocol for the gram-scale (2.5 g) kinetic resolution of a model aryl-vinyl (sp² vs. sp² ) substituted secondary alcohol is demonstrated, giving access to >1 g of each of the product enantiomers both in 99:1 e.r.