Modular POP Ligands in Rhodium-Mediated Asymmetric Hydrogenation: A Comparative Catalysis Study
作者:José L. Núñez-Rico、Pablo Etayo、Héctor Fernández-Pérez、Anton Vidal-Ferran
DOI:10.1002/adsc.201200477
日期:2012.11.12
Highly efficient and enantioselectivehydrogenation reactions for α-(acylamino)acrylates, itaconic acid derivatives and analogues, α-substituted enolester derivatives, and α-arylenamides (25 substrates) catalyzed by chiral cationic rhodium complexes of a set of POP ligands have been developed. The catalytic systems derived from these POP ligands provided a straightforward access to enantiomerically
Asymmetric Hydrogenation with Highly Active IndolPhos-Rh Catalysts: Kinetics and Reaction Mechanism
作者:Jeroen Wassenaar、Mark Kuil、Martin Lutz、Anthony L. Spek、Joost N. H. Reek
DOI:10.1002/chem.200903476
日期:2010.6.11
The mechanism of the IndolPhos–Rh‐catalyzed asymmetrichydrogenation of prochiral olefins has been investigated by means of X‐ray crystal structure determination, kinetic measurements, high‐pressure NMR spectroscopy, and DFT calculations. The mechanistic study indicates that the reaction follows an unsaturate/dihydride mechanism according to Michaelis–Menten kinetics. A large value of KM (KM=5.01±0
通过X射线晶体结构测定,动力学测量,高压NMR光谱和DFT计算,研究了IndolPhos–Rh催化的前手性烯烃不对称氢化的机理。机理研究表明,根据米利斯(Michaelis-Menten)动力学,该反应遵循不饱和/二氢键机理。K M的较大值(K M = 5.01±0.16 M),表明Rh-溶剂合物是催化剂的静止状态,已通过高压NMR光谱观察到。通过实验手段无法检测到的底物-催化剂复合物的DFT计算表明,主要的底物-催化剂复合物导致了产物。这种机理与先前关于与C 1对称的异位和单齿配体的不对称氢化反应机理的研究一致。
Chiral Rhodium Complexes Derived From Electron-Rich Phosphine-Phosphites as Asymmetric Hydrogenation Catalysts
作者:Pablo Etayo、José L. Núñez-Rico、Anton Vidal-Ferran
DOI:10.1021/om200933b
日期:2011.12.26
Two new chiral cationic rhodium(I) complexes derived from electron-rich dicyclohexylphosphine-phosphite ligands were prepared from enantiopure Sharpless epoxy ethers. The best-performing catalyst system, which bears a less bulky methyl ether moiety, exhibited remarkably high enantioselectivity (up to 99% ee) and reactivity (up to >2500 TON) in asymmetric hydrogenation reactions of various functionalized
Highly Modular POP Ligands for Asymmetric Hydrogenation: Synthesis, Catalytic Activity, and Mechanism
作者:Héctor Fernández-Pérez、Steven M. A. Donald、Ian J. Munslow、Jordi Benet-Buchholz、Feliu Maseras、Anton Vidal-Ferran
DOI:10.1002/chem.200902915
日期:2010.6.11
pure POPligands (phosphine–phosphite), straightforwardly available in two synthetic steps from enantiopure Sharpless epoxy ethers is reported. Both the alkyloxy and phosphite groups can be optimized for maximum enantioselectivity and catalyticactivity. Their excellent performance in the Rh‐catalyzed asymmetrichydrogenation of a wide variety of functionalized alkenes (26 examples) and modular design
the asymmetric hydrogenation of imines and olefins. The iridium-catalyzedhydrogenation of imines provided up to 81 % ee, whereas in the rhodium-catalyzed hydrogenation of functionalized olefinsenantioselectivities of up to 99 % ee were achieved. In this particular application, the different chiral elements of the ligand structure led to synergistic effects and the enantioselectivity is dominated by
基于蒎烯衍生的手性胺的亚磷酰胺配体已通过简单的程序以良好的产率制备。合成方案的关键步骤是对环状蒎烯-吡啶衍生物进行立体选择性氢化,产生(非对映异构)仲胺,仲胺被分离并用不同的氯亚磷酸酯处理以产生设想的亚磷酰胺。配体的绝对构型是在 NMR 分析的基础上确定的,并通过典型配体的硼烷加合物的 X 射线衍射分析得到证实。新配体用于亚胺和烯烃的不对称氢化。亚胺的铱催化氢化提供高达 81% ee,而在官能化烯烃的铑催化氢化中,实现了高达 99% ee 的对映选择性。