Ammonia Catalysed Aldol and Mannich Reactions

21 February 2006

Ammonia has been found to be a useful reagent/catalyst for reactions of aromatic and heteroaromatic aldehydes with ketones such as acetone, though with methyl ethyl ketone product mixtures arise. Chloral also reacts in the same way.

With electron rich aromatics and indole and pyrrole carboxaldehydes further Mannich-type
reactions occur to give cyclised products (Feng L et al, Tetrahedron Lett, 2005, 46, 8685).