Potassium phosphate–ionic liquid mediated selective mono-Michael addition

A simple and efficient process for an exclusive mono-Michael addition of active methylene compounds to conjugated esters, nitriles and ketones is developed. An ionic liquid-mediated reaction is carried out at room temperature. A reaction carried out at 60 °C resulted in a double-addition product. A mechanism is proposed and supported by P31 and DOSY NMR analysis of the used ionic liquid.