Isomerization of allylic alcohols in water catalyzed by transition metal complexes

Isomerisation of allylic alcohols in water mediated catalytically by water soluble metal complexes is an elegant synthetic procedure for obtaining carbonyl compounds in a completely atom-economical ecobenign process with several useful applications in natural-product synthesis and in bulk chemical processes. This review is targeted to provide a general view of the goals obtained in isomerisation catalysis in water. Complexes that catalyze the isomerization of allylic alcohols in water, together with ligands and reaction conditions are compared with respect to yield, turnovers, rate and selectivity. A general overview of the mechanisms proposed for the isomerisation of allylic alcohols is also presented. Crystal structures and selected bond lengths are presented for the most representative catalytically active metal complexes.