First asymmetric cascade reaction catalysed by chiral primary aminoalcohols

Abstract

Readily available chiral primary 1,2-aminoalcohols and diamines have been explored as organocatalysts for a domino Michael–aldol reaction. Their application in this organocascade process afforded cyclohexanone A with high levels of reactivity (up to 91% yield) and stereoselectivity (>97 : 3 d.r., up to 93% ee). Depending on the acid cocatalyst different chiral species (cyclic secondary aminesvs. acyclic primary amines) might catalyse the process. In order to shed light on the catalytic activation, several experiments were carried out and a detailed possible reaction mechanism is proposed. Theoretical studies support the stereochemical outcome of the process.