| Citation | John M Brown is a physical organic chemist whose interests are directed towards the understanding of processes relevant to organic chemical synthesis. Although his first major achievement was the solution of the transient cis-divinylcyclopropane central to the question of the Cope rearrangement, his major efforts have been on homogenous asymmetric catalysis. His study of the rhodium catalysed hydrogenation of enamides, by NMR and isotopic methods, contributed greatly to our current understanding of the subtle mechanism of this process. Extension to the iridium system led to a a new method for the resolution of biphosphines and insights were gained both into hydroformylation and cross-coupling reactions. His discovery of asymmetric hydrogenation of allylic alcohols has opened up a powerful technique for synthetic chemists, ranging from direct preparation of optically active materials to kinetic resolutions. His methods are now widely used. |