of enantioenriched (hetero)aromatic secondary allylic alcohols has been synthesized through deracemization of the corresponding racemic mixtures combining a non-selective chemoenzymatic oxidation (laccase from Trametes versicolor and oxy-radical TEMPO) and a stereoselective biocatalyzed reduction (lyophilized cells of E. coli overexpressing an alcoholdehydrogenase, ADH). Both steps were performed in
Palladium Catalysed Coupling Reactions using Guanidinium Phosphine Complexes on Glass Beads
作者:Mathew P. Leese、Jonathan M. J. Williams
DOI:10.1055/s-1999-2907
日期:——
Supported palladium catalysts generated from guanidinium phosphine 1 and palladium acetate have been shown to exhibit high activity and low leaching of catalyst. The nature of the catalyst allows facile separation and recycling.
An efficient Ir(III) dihydride complex catalyzed 1,3-rearrangement of allylicalcohols was realized, affording the corresponding less easily accessible allylicalcohols regio- and stereoselectively in high yields from readily available starting materials. The reaction pathway involves a π-allyl-Ir(V) intermediate and the dihydride in Ir(III) dihydride complex acts as the hydrogen switch to modulate