Hydroxylamine as a Superior Organocatalyst for Morita-Baylis-Hillman Reaction

Computational investigations indicate that the use of N,N-dimethylhydroxylamine as organocatalyst enhances the rate of Morita-Baylis-Hillman reaction by lowering the activation energy of the rate-controlling aldol step. The rate enhancement is understood to originate from the a-effect of oxygen on nitrogen in hydroxylamine, which enhances the nucleophilicity of the nitrogen and results in its more effective conjugate addition to the enone to form an advanced and, thus, reactive enolate to participate in the aldol process. The activation energy of the aldol reaction is therefore reduced.