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Verley type transition state 8 (Scheme 3). The use of acetone cyanohydrin as a cyanide source takes advantage of both the reversibility of cyanohydrin synthesis and the steric influence on the position of the equilibrium, which is generally more favorable for addition to aldehydes than to ketones.Acyl cyanides, 9 cyanoformates, 10 and cyanophosphonates 11 can also be used as cyanating agents and have the major advantage of producing O-protected cyanohydrins which do not revert to carbonyl compounds; thus, the cyanohydrin formation becomes irreversible, and even substrates for which the equilibrium between carbonyl compound and cyanohydrin is unfavorable can be prepared Michael North was born in Blackburn, England, in 1964. He obtained his B.Sc. in 1985 from the University of Durham and his D.Phil. in 1988 from the University of Oxford for work on the synthesis of nonracemic amino acids carried out in the group of Professor Sir J. E. Baldwin. After a two-year postdoctoral position in Professor G. Pattenden's research group at the University of Nottingham, he was appointed to his first academic post at the University of Wales at Bangor. In 1999 he moved to King's College London and was promoted to Professor of synthetic organic chemistry in 2001. In 2004, he moved to his current position as Professor of organic chemistry and joint director of the University Research Centre in Catalysis and Intensified Processing at the University of Newcastle upon Tyne. Professor North has published over 100 original papers and also holds five patents. His research interests are centered on the design and mechanistic study of new catalysts with applications including asymmetric carbon-carbon bond formation, carbon dioxide chemistry, and polymer chemistry. In 2001 he was awarded the Descartes Prize by the European Commission for his work on asymmetric cyanohydrin synthesis using metal(salen) complexes.

The effect of moderate temperatures (22-100 °C) and pressures (1-10 bar) on the synthesis of cyclic carbonates from epoxides and carbon dioxide catalyzed by a combination of bimetallic aluminum complexes and tetrabutylammonium bromide is investigated. The combined bimetallic complex and tetrabutylammonium bromide catalyst system is shown to be an order of magnitude more active than the use of tetrabutylammonium bromide alone at all temperatures and pressures studied. At the higher temperatures and pressures used, disubstituted epoxides become substrates for the reaction and it is shown that reactions proceed with retention of the epoxide stereochemistry. This allowed a route for the overall syn-bis-hydroxylation of alkenes to be developed without the use of hazardous metal based reagents. At higher pressures it is also possible to use compressed air as the carbon dioxide source.

The development of one-component, bimetallic μ-oxoaluminium(salen) complexes as highly active catalysts for the synthesis of cyclic carbonates from terminal epoxides is described. The resulting homogeneous catalysts are used in batch reactions at room temperature and one atmosphere pressure. The catalysts have also been immobilized onto various support materials and used in either batch reactions or gas-phase flow reactions with ethylene and propylene oxides. Catalyst lifetime, deactivation and reactivation have been studied in both batch and flow reactions, and it has been shown that of the impurities present in power station flue gas, only sulfur trioxide deactivates the catalyst and at the concentrations of sulfur trioxide present in flue gas, this deactivation would require more than one years exposure of the catalyst to flue gas.

The impact of flue gas from the combustion of natural gas or coal in a combustion test facility on the activity of catalysts for the synthesis of cyclic carbonates from epoxides and waste carbon dioxide has been investigated. In batch reactions with styrene oxide as substrate, some loss of catalyst activity was apparent and this was greater for catalyst exposed to flue gas generated from burning coal than for catalyst exposed to flue gas obtained by burning gas. In a gas-phase flow reactor with ethylene oxide as substrate, the detrimental effect of flue gas exposure on catalyst activity was much less apparent.