Kinetic Resolution in Asymmetric Epoxidation using Iminium Salt Catalysis (original) (raw)

Iminium Salt-Catalysed Asymmetric Epoxidation using Hydrogen Peroxide as Stoichiometric Oxidant

Advanced Synthesis & Catalysis, 2008

Iminium salt organocatalysts can provide high selectivity and high efficiency in catalytic asymmetric epoxidation. They are normally used in conjunction with Oxone as the stoichiometric oxidant. Oxone, however, has limited stability and is insoluble in most organic solvents; we report here for the first time the development of a reaction system driven by hydrogen peroxide as the stoichiometric oxidant, involving an unusual double catalytic cycle.

Asymmetric Epoxidation Using Iminium Salt Organocatalysts Featuring Dynamically Controlled Atropoisomerism

The Journal of …, 2012

ntroduction of a pseudoaxial substituent at a stereogenic center adjacent to the nitrogen atom in binaphthyl- and biphenyl-derived azepinium salt organocatalysts affords improved enantioselectivities and yields in the epoxidation of unfunctionalized alkenes. In the biphenylderived catalysts, the atropoisomerism at the biphenyl axis is controlled by the interaction of this substituent with the chiral substituent at nitrogen.

ChemInform Abstract: Recent Aspects of Enantioselective Epoxidation Reactions

ChemInform, 2010

The latest accepted mechanisms of KatsulSharpless epoxldation, proposed by Sharpless and Corey independently, have been described. The recent developments of chiral porphyrin and salen-based metal complexes and their uses as catalysts for asymmetric epoxidat~on of unfunctionalized olefins (non-directed epoxidation) have been briefly reviewed.