对映选择合成
烯烃
立体中心
复分解
催化作用
组合化学
化学
盐变质反应
有机化学
聚合
聚合物
作者
Steven J. Malcolmson,Simon J. Meek,Elizabeth S. Sattely,Richard R. Schrock,Amir H. Hoveyda
出处
期刊:Nature
[Springer Nature]
日期:2008-11-16
卷期号:456 (7224): 933-937
被引量:267
摘要
Discovery of efficient catalysts is one of the most compelling objectives of modern chemistry. Chiral catalysts are in particularly high demand, as they facilitate synthesis of enantiomerically enriched small molecules that are critical to developments in medicine, biology and materials science. Especially noteworthy are catalysts that promote-with otherwise inaccessible efficiency and selectivity levels-reactions demonstrated to be of great utility in chemical synthesis. Here we report a class of chiral catalysts that initiate alkene metathesis with very high efficiency and enantioselectivity. Such attributes arise from structural fluxionality of the chiral catalysts and the central role that enhanced electronic factors have in the catalytic cycle. The new catalysts have a stereogenic metal centre and carry only monodentate ligands; the molybdenum-based complexes are prepared stereoselectively by a ligand exchange process involving an enantiomerically pure aryloxide, a class of ligands scarcely used in enantioselective catalysis. We demonstrate the application of the new catalysts in an enantioselective synthesis of the Aspidosperma alkaloid, quebrachamine, through an alkene metathesis reaction that cannot be promoted by any of the previously reported chiral catalysts.
科研通智能强力驱动
Strongly Powered by AbleSci AI