Titanium<i>cis</i>-1,2-Diaminocyclohexane (<i>cis</i>-DACH) Salalen Catalysts for the Asymmetric Epoxidation of Terminal Non-Conjugated Olefins with Hydrogen Peroxide
Chiral Ti salalen complexes catalyze the asymmetric epoxidation of terminal non‐conjugated olefins with hydrogen peroxide. Modular ligands based on cis‐1,2‐diamino‐cyclohexane (cis‐DACH) were developed, giving high yields and enantiomeric excesses (ee, up to 96 %) at catalyst loadings as low as 0.1–0.5 mol %, and even under solvent‐free conditions.
Titanium Salalen Catalysts Based on<i>cis</i>-1,2-Diaminocyclohexane: Enantioselective Epoxidation of Terminal Non-Conjugated Olefins with H<sub>2</sub>O<sub>2</sub>
Help for the neglected: Terminal, non‐conjugated olefins, such as 1‐octene, are difficult to epoxidize asymmetrically. Ti salalen complexes based on cis‐1,2‐diaminocyclohexane catalyze this demanding reaction giving high yields and enantioselectivities (up to 95 % ee), with H2O2 as the oxidant. The X‐ray structures of the μ‐oxo and peroxocomplexes shed light on the coordination behavior of this novel
被忽视的帮助:末端非共轭烯烃(例如1-辛烯)难以不对称环氧化。基于顺式1,2-二氨基环己烷的Ti salalen络合物以H 2 O 2为氧化剂,可催化要求苛刻的反应,从而提供高收率和对映选择性(最高95% ee)。μ-oxo和peroxo配合物的X射线结构阐明了这类新型配体的配位行为。
Bioproduction of Chiral Epoxyalkanes using Styrene Monooxygenase from<i>Rhodococcus</i>sp. ST-10 (RhSMO)
作者:Hiroshi Toda、Ryouta Imae、Nobuya Itoh
DOI:10.1002/adsc.201400383
日期:2014.11.3
AbstractWe describe the enantioselective epoxidation of straight‐chain aliphatic alkenes using a biocatalytic system containing styrene monooxygenase from Rhodococcus sp. ST‐10 and alcohol dehydrogenase from Leifsonia sp. S749. The biocatalyzed enantiomeric epoxidation of 1‐hexene to (S)‐1,2‐epoxyhexane (>44.6 mM) using 2‐propanol as the hydrogen donor was achieved under optimized conditions. The biocatalyst had broad substrate specificity for various aliphatic alkenes, including terminal, internal, unfunctionalized, and di‐ and tri‐substituted alkenes. Here, we demonstrate that this biocatalytic system is suitable for the efficient production of enantioenriched (S)‐epoxyalkanes.magnified image
Pheromones
申请人:Cross Jeremy Vincent
公开号:US20080279810A1
公开(公告)日:2008-11-13
The apple leaf midge and raspberry cane midge pheromones have been found to be acetoxyheptadecenone and acetoxyundecanone, respectively, and uses for these and related compounds are provided, including monitoring population levels of the midge and control of midge populations by disrupting mating patterns.