197087-56-2Relevant academic research and scientific papers
Diaza-Crown Ether-Bridged Chiral Diphosphoramidite Ligands: Synthesis and Applications in Asymmetric Catalysis
Luo, Yier,Ouyang, Guanghui,Tang, Yuping,He, Yan-Mei,Fan, Qing-Hua
, p. 8176 - 8184 (2020/07/15)
A small library of diaza-crown ether-bridged chiral diphosphoramidite ligands was prepared. In the rhodium-catalyzed asymmetric hydrogenation and hydroformylation reactions, these ligands exhibited distinct properties in catalytic activity and/or enantioselectivity. Hydrogenated products with opposite absolute configurations could be obtained in high yields with excellent ee values by utilizing (S,S)-L1 and (S,S)-L3, respectively. Meanwhile, the addition of alkali metal cations caused variations in catalytic outcomes, showing the supramolecular tunability of these Rh/diphosphoramidite catalytic systems.
Chiral Rh phosphine-phosphite catalysts immobilized on ionic resins for the enantioselective hydrogenation of olefins in water
Kleman,Barbaro,Pizzano
supporting information, p. 3826 - 3836 (2015/07/15)
The asymmetric hydrogenation of prochiral enamides with Rh complexes bearing chiral phosphine-phosphite ligands (P-OP) supported on sulphonated polystyrene resins has been studied. The complexes have been supported by simple treatment of preformed [Rh(dio
Enantioselective hydrogenation of α-dehydroamino acid esters catalyzed by rhodium complexes with chiral bisaminophosphine ligands
Sun, Xianfeng,Li, Wei,Zhou, Le,Zhang, Xumu
supporting information; experimental part, p. 1150 - 1154 (2010/06/20)
A highly efficient strategy for the synthesis of a series of chiral bisaminophosphine ligands was well established with several remarkable features. The synthetic utility of these ligands was explored for rhodium-catalyzed asymmetric hydrogenations of α-d
Design and synthesis of a novel three-hindered quadrant bisphosphine ligand and its application in asymmetric hydrogenation
Huang, Kexuan,Zhang, Xiaowei,Emge, Thomas J.,Hou, Guohua,Cao, Bonan,Zhang, Xumu
supporting information; experimental part, p. 8555 - 8557 (2011/01/03)
A novel three hindered quadrant bisphosphine ligand has been synthesized. The ligand shows excellent enantioselectivities and reactivities for rhodium-catalyzed hydrogenations of various functionalized olefins.
Supramolecular chiral dendritic monophosphites assembled by hydrogen bonding and their use in the Rh-catalyzed asymmetric hydrogenation
Li, Yong,He, Yan-Mei,Li, Zhi-Wei,Zhang, Feng,Fan, Qing-Hua
experimental part, p. 1890 - 1895 (2009/06/28)
A new type of supramolecular chiral dendritic monophosphite ligands has been prepared via a hydrogen-bonding assembly. The Rh complexes of these supramolecular ligands have been successfully applied in the asymmetric hydrogenation of enamides and dehydroa
Synthesis of atropisomeric 5,5′-linked biphenyl bisaminophosphine ligands and their applications in asymmetric catalysis
Zhang, Yong Jian,Wei, Hao,Zhang, Wanbin
experimental part, p. 1281 - 1286 (2009/04/18)
Atropisomeric 5,5′-linked biphenyl bisaminophosphine ligands 2 has been synthesized. The axial chirality of this type of ligands can be retained by macro-ring strain produced from 5,5′-linkage of biphenyl even without 6,6′-substituents on biphenyls. The Rh complex of bisaminophosphine 2a as a catalyst is effectively working in the asymmetric hydrogenation of methyl (Z)-2-acetamido-3-arylacrylates, however, for hydrogenation of arylenamide, the low enantioselectivity was observed. When the ligands applied to Pd-catalyzed allylic alkylation, it is found that ligand 2b having a longer backbone linkage is a better ligand for enantioselection in the reaction.
Access to enantioenriched α-amino esters via rhodium-catalyzed 1,4-addition/enantioselective protonation
Navarre, Laure,Martinez, Remi,Genet, Jean-Pierre,Darses, Sylvain
, p. 6159 - 6169 (2008/12/20)
Conjugate addition of potassium trifluoro(organo)borates 2 to dehydroalanine derivatives 1, mediated by a chiral rhodium catalyst and in situ enantioselective protonation, afforded straightforward access to a variety of protected α-amino esters 3 with high yields and enantiomeric excesses up to 95%. Among the tested chiral ligands and proton sources, Binap, in combination with guaiacol (2-methoxyphenol), an inexpensive and nontoxic phenol, afforded the highest asymmetric inductions. Organostannanes have also shown to participate in this reaction. By a fine-tuning of the ester moiety, and using Difluorophos as chiral ligand, increased levels of enantioselectivity, generally close to 95%, were achieved. Deuterium labeling experiments revealed, and DFT calculation supported, an unusual mechanism involving a hydride transfer from the amido substituent to the α carbon explaining the high levels of enantioselectivity attained in controlling this α chiral center.
Supramolecular chiral phosphorous ligands based on a [2]pseudorotaxane complex for asymmetric hydrogenation
Li, Yong,Feng, Yu,He, Yan-Mei,Chen, Fei,Pan, Jie,Fan, Qing-Hua
, p. 2878 - 2881 (2008/09/21)
A new type of supramolecular chiral phosphorus-based ligands was prepared from easily available monodentate ligands through complexation between dibenzylammonium salt and dibenzo[24]crown-8 macrocycle. Rhodium complexes with these supramolecular ligands w
Novel atropisomeric aminophosphine ligands with a bridge across the 5,5′-position of biphenyl for Rh(I)-catalyzed asymmetric hydrogenation
Wei, Hao,Zhang, Yong Jian,Dai, Yijun,Zhang, Jiaming,Zhang, Wanbin
, p. 4106 - 4109 (2008/09/21)
A new type of atropisomeric bisaminophosphine ligands 2 with a bridge across the 5,5′-position of biphenyl has been developed. The axial chirality of this type of ligands can be retained by macro-ring strain produced from 5,5′-linkage of biphenyl even wit
Synthesis of a novel spiro bisphosphinite ligand and its application in Rh-catalyzed asymmetric hydrogenation
Guo, Zhenqiu,Guan, Xiaoyu,Chen, Zhiyong
, p. 468 - 473 (2007/10/03)
A novel, chiral bisphosphinite ligand (R)-SpiroBIP has been synthesized. The rhodium complex of the ligand was found to be highly enantioselective in the asymmetric hydrogenation of α-dehydroamino acid derivatives.
