Rhodium Chemzymes: Michaelis−Menten Kinetics in Dirhodium(II) Carboxylate-Catalyzed Carbenoid Reactions
作者:Michael C. Pirrung、Hao Liu、Andrew T. Morehead
DOI:10.1021/ja011599l
日期:2002.2.1
bind both to the free catalyst and to the catalyst-substrate complex. Substrate inhibition can also be exhibited by diazocompounds bearing these groupings in addition to the diazogroup. The analysis of inhibition shows that the active catalyst uses only one of its two coordination sites at a time for catalysis. Some ketones exhibit the interesting property that they selectively bind to the catalyst-substrate
羧酸铑介导的重氮酮反应,包括环丙烷化、CH 插入和芳香 CC 双键加成/电环开环遵循饱和 (Michaelis-Menten) 动力学。铑的轴向配体,包括芳烃和路易斯碱,如腈、醚和酮,通过混合动力学抑制机制抑制这些反应,这意味着它们可以与游离催化剂和催化剂-底物复合物结合。除了重氮基团之外,带有这些基团的重氮化合物也可以表现出底物抑制作用。抑制分析表明,活性催化剂一次仅使用其两个配位点之一进行催化。一些酮表现出有趣的特性,即它们选择性地与催化剂-底物复合物结合。无论连接单元或反应烯烃的环境如何,来自具有相似重氮酮的不同类型反应的动力学常数的相似性表明,速率决定步骤是生成铑卡宾。一种用于不对称合成的非常有用的羧酸铑催化剂,Rh(2)(DOSP)(4),显示出比非手性催化剂稍慢的动力学参数,这意味着该催化剂的对映选择性是基于减缓其中一个对映体面的反应。反应物,而不是任何类型的配体加速催化。一系列从
Efficient synthesis of bicyclo[5.3.0]decatrienones and of 2-tetralones via rhodium(<scp>II</scp>) acetate-catalysed cyclisation of α-diazoketones derived from 3-arylpropionic acids
作者:M. Anthony McKervey、Sarbajna M. Tuladhar、M. Fiona Twohig
DOI:10.1039/c39840000129
日期:——
Rhodium (II) acetate-catalysed cyclisation of α-diazoketones derivedfrom 3-arylpropionic acid produces bicyclo[5.3.0]decatrienones or 2-tetralones depending on the substitution pattern of the aryl ring: the former products are transformed into the latter by catalytic amount of trifluoroacetic acid.
The intramolecular Buchner reaction of aryl diazoketones. Substituent effects and scope in synthesis
作者:Michael Kennedy、M. Anthony McKervey、Anita R. Maguire、Sarbajna M. Tuladhar、M. Fiona Twohig
DOI:10.1039/p19900001047
日期:——
cyclisation occurring in all cases. When the precursor contains a meta-methoxy substituent, 2-tetralones are obtained directly. The efficient conversion of 3-phenylpropionic acid into trans-1-methylbicyclo[5.3.0]decan-2-one is also described, partial asymmetric synthesis having been realised through the use of rhodium (S)-mandelate as the cyclisation catalyst. Cyclisations of diazoketonesderived from