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Philip C Bulman Page

Philip C Bulman Page

University of East Anglia, UK

Title: New Systems for Organocatalytic Asymmetric Epoxidation

Biography

Phil Page graduated from the Department of Chemistry, Imperial College London in 1975, and obtained his PhD from the same institution in 1978 under the supervision of Prof S V Ley. He spent two years working with Prof L A Paquette at Ohio State University as an SERC/NATO Research Fellow before moving to the University of Liverpool as a lecturer in 1983. He moved to the chair of organic chemistry at Loughborough University in 1996, and to the chair of organic chemistry at the University of East Anglia in 2007. He has published over 200 articles, and has won a Nuffield Foundation Science Research Fellowship, the Royal Society of Chemistry Hickinbottom Fellowship, the Royal Society of Chemistry Tilden Medal, the Glaxo-Wellcome Award for Innovative Chemistry, and a Royal Society Industry Fellowship. His research interests lie principally in asymmetric synthesis/catalysis, synthetic methodology and natural product synthesis. Prof Page, a Kentish Man, is married and lives with one wife and three cats. His hobbies include chemistry, reading, hi fi and music, not necessarily all at once, and food and drink. 

Abstract

The development of methods for the introduction of asymmetry into organic molecules remains a topic of great importance. Catalytic systems are particularly desirable, and the combination of a catalytic asymmetric process with an environmentally friendly reaction system and an inexpensive oxidant offers an especially attractive goal. Non-racemic chiral epoxides are important intermediates for enantioselective carbon-carbon bond formation. We are developing organocatalytic systems in which asymmetric oxidants are formed by reaction of iminium salts with simple oxidants under mild conditions. We currently formulate the reactive intermediates as oxaziridinium ions, from which the iminium salt mediators are regenerated following oxygen transfer to alkene substrates. We can accomplish epoxidation of simple alkenes with up to ca 99% ee. Catalyst loading may be as low as 0.1 mol%. The epoxidation reactions may be carried out under aqueous or non-aqueous conditions. The iminium salt mediators can be easily prepared without chromatography in many cases, and the procedures used are simple to carry out, and require no preparation of unstable reagents. The lecture will discuss recent developments including new generations of catalyst, the first examples of kinetic resolution, the use of non-aqueous as well as the usual aqueous conditions, and alternative oxidants in place of Oxone, including hydrogen peroxide, bleach, and even electrochemical conditions by oxidant generation at boron-doped diamond electrodes.