Baylis–Hillman reaction

The Baylis -Hillman reaction, and Morita -Baylis -Hillman reaction is a reaction in the field of organic chemistry and was named after their discoverers, Anthony B. Baylis and Melville ED Hillman. It is used in the synthesis of α - Hydroxyvinylcarbonylen. For this purpose, a vinyl ketone or ester, an aldehyde or ketone, and a base is required. As the base, classic triethylene diamine (DABCO ) is used, more recently, DBU and DMAP.

Mechanism

The following illustration shows a plausible reaction course:

In the first step, the base attacks ( in this case, DABCO, with abbreviated B ) the nucleophilic vinyl ketone 1, so that the resonance-stabilized enolate 2 forms. This now takes the aldehyde / ketone to form the alkoxide 3 to nucleophilic. Under the proton transfer, the removal of the base and the product 4 are formed. The reaction proceeds very slowly, but can be accelerated by ultrasound.

The reaction also proceeds with imines or imine derivatives instead of aldehydes / ketones.