Different α-alkoxy and α,β-di-alkoxy substituted aldehydes have been submitted to the catalytic action of the oxynitrilases from almond (PaHNL) or from Hevea brasiliensis (HbHNL), in order to explore the possibility of using these enzymes for the preparation of complex cyanohydrins. The selectivity of both enzymes towards these compounds was found to be largely dependent on the substitutents, being
A Mechanistically Guided Design Leads to the Synthesis of an Efficient and Practical New Reagent for the Highly Enantioselective, Catalytic Dihydroxylation of Olefins
作者:Jinkun Huang、E. J. Corey
DOI:10.1021/ol035192s
日期:2003.9.1
[structure: see text] The catalytic asymmetric dihydroxylation of olefins has been accomplished with high enantioselectivities using a proline-based catalyst. The pre-transition-state assembly for styrene is shown.
Enantioselective vicinal hydroxylation of terminal and E-1,2-disubstituted olefins by a chiral complex of osmium tetroxide. An effective controller system and a rational mechanistic model
作者:E. J. Corey、Paul DaSilva Jardine、Scott Virgil、Po Wai Yuen、Richard D. Connell
DOI:10.1021/ja00208a025
日期:1989.12
The suprafacial hydroxylation of olefins by osmium tetraoxide, though a much used synthetic method, would become even more important if three conditions could be met: (1) modification to achieve high and predictable enantioselectivity and acyclic diastereoselectivity, (2) clarification of reaction mechanism, and (3) facilitated recovery and recycling of osmium. This paper reports progress on all three
Enantioselective sensing of insect pheromones in water
作者:Briana L. Hickey、Junyi Chen、Yunfan Zou、Adam D. Gill、Wenwan Zhong、Jocelyn G. Millar、Richard J. Hooley
DOI:10.1039/d1cc05540b
日期:——
cavitands and cationic dyes has been shown to optically sense insectpheromones at micromolar concentration in water. Machine learning approaches were used to optimize the most effective array components, which allows differentiation between small structural differences in targets, including between different diastereomers, even though the pheromones have no innate chromophore. When combined with chiral additives
Syntheses of isotopically labelled L-α-amino acids with an asymmetric centre at C-3
作者:John R. Harding、Rachael A. Hughes、Nicholas M. Kelly、Andrew Sutherland、Christine L. Wilis
DOI:10.1039/b005172l
日期:——
Approaches are described to the synthesis of a series of isotopicallylabelled L-α-amino acids each with an asymmetric centre at C-3, including isoleucine, allo-isoleucine, threonine and allo-threonine. The methods may be simply adapted for the selective incorporation of an isotopiclabel at each site of L-valine including the selective labelling of either diastereotopic methyl group with carbon-13