Heinrich Emil Albert Knoevenagel ( 18 June 1865 - 11 August 1921) was the German chemist who established the "Knoevenagel condensation reaction". The Knoevenagel condensation reaction of benzaldehydes with nitroalkanes is a classic general method for the preparation of nitroalkenes, which are very valuable synthetic intermediates.
In the Knoevenagel condensation reaction an aldehyde or a ketone reacts with the enolate anion formed from a molecule which has an acidic hydrogen atom which is alpha to two activating groups (either a carbonyl or cyano group); the elimination of a water molecule occurs readily leading to an alpha, beta unsaturated compound .
