Enantioselective Synthesis of α-Hydroxy and α-Amino Phosphonates via Catalytic Asymmetric Hydrogenation
摘要:
[GRAPHICS]Cationic rhodium catalysts of the C-2 symmetric DuPHOS (1) and BPE (2) ligands have demonstrated the ability to asymmetrically hydrogenate a novel series of enol phosphonates (3) in good to excellent enantiomeric excess under mild conditions. Initial studies toward the catalytic asymmetric hydrogenation of enamido phosphonates (6 and 7) using the DuPHOS-Rh+ catalysts are also reported.
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。
Asymmetric hydrogenation of α- or β-acyloxy α,β-unsaturated phosphonates catalyzed by a Rh(i) complex of monodentate phosphoramidite
The Rh(I) complex of a monodentate phosphoramidite bearing a primary amine moiety (DpenPhos) has been disclosed to be highly efficient for the asymmetric hydrogenation of a variety of α- or β-acyloxyα,β-unsaturatedphosphonates, providing the corresponding biologically important chiral α- or β-hydroxy phosphonic acid derivatives with excellent enantioselectivities (90–>99% ee).
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