A new chiral catalyst for olefin metathesis is prepared from commercially available materials and is equally or more effective and selective than the previous systems. The new user-friendly catalyst can be prepared in situ (see scheme, Ar=aryl, Tf=trifluoromethanesulfonyl), isolation not needed, outside of a glove box, and delivers reactivity and enantioselectivity levels formerly available only through
Mechanistically Inspired Catalysts for Enantioselective Desymmetrizations by Olefin Metathesis
作者:Pierre-André Fournier、Jolaine Savoie、Brice Stenne、Marion Bédard、Alain Grandbois、Shawn K. Collins
DOI:10.1002/chem.200800642
日期:2008.9.26
In asymmetric olefin metathesis reactions, the addition of halideadditives is often required to augment enantioselectivities, despite the fact that the additives result in catalysts with diminished reactivities. The preparation of new chiral Ru-based catalysts was accomplished by exploiting previously reported mechanistic studies. The catalysts possess a high level of reactivity and successfully induce
Chiral Mo−Binol Complexes: Activity, Synthesis, and Structure. Efficient Enantioselective Six-Membered Ring Synthesis through Catalytic Metathesis
作者:S. Sherry Zhu、Dustin R. Cefalo、Daniel S. La、Jennifer Y. Jamieson、William M. Davis、Amir H. Hoveyda、Richard R. Schrock
DOI:10.1021/ja991432g
日期:1999.9.1
to obtain optically pure products in high yield from catalytic reactions without the use of solvent (cf. eq 1). The structural attributes of these complexes are detailed on the basis of the data available from an X-ray structure and variable-temperature 1H NMR studies. The results of this investigation indicate the following: (i) The anti-Mo·THF complex exists as a mixture of diastereomers, whereas the
公开了一类带有官能化手性二元醇配体的新型手性钼基配合物2a和2b。Mo 配合物 2a 促进了各种二烯和三烯的不对称闭环复分解 (ARCM),以有效地提供高光学纯度的六元碳环和杂环。基于二元醇的手性 Mo 催化剂补充了先前报道的基于联苯的配合物,它们在通过 ARCM 对映选择性合成五元环中特别有效。描述了关于催化动力学分辨率和不对称去对称化的研究。在不使用溶剂的情况下,可以从催化反应中以高产率获得光学纯的产物(参见方程式 1)。这些配合物的结构属性根据 X 射线结构和可变温度 1H NMR 研究中的可用数据进行了详细说明。这项研究的结果表明:(i) 抗 Mo·THF 复合物以非对映异构体的混合物形式存在,而顺式异构体......
Dolman, Sarah J.; Hultzsch, Kai C.; Pezet, Frederic, Journal of the American Chemical Society, 2004, vol. 126, # 35, p. 10944 - 10953
作者:Dolman, Sarah J.、Hultzsch, Kai C.、Pezet, Frederic、Teng, Xin、Hoveyda, Amir H.、Schrock, Richard R.