Modular Monodentate Phosphoramidite Ligands for Rhodium-Catalyzed Enantioselective Hydrogenation
作者:Yan Liu、Kuiling Ding
DOI:10.1021/ja052749l
日期:2005.8.1
A new class of monodentate phosphoramidite ligands (DpenPhos) has been developed on the basis of the modular concept for Rh(I)-catalyzed asymmetric hydrogenations of a variety of olefin derivatives, affording the corresponding optically active compounds in excellent yields and enantioselectivities. The ligands have the advantages of facile preparation, tunable structure, and broad scope of substrates
Concise synthesis and applications of enantiopure spirobiphenoxasilin-diol and its related chiral ligands
作者:Lei Yang、Wen-Qiang Xu、Tao Liu、Yichen Wu、Biqin Wang、Peng Wang
DOI:10.1039/d1cc05576c
日期:——
for asymmetriccatalysis. Herein, we report the concise synthesis of a Si-centered spirocyclic skeleton, spirobiphenoxasilin-diol (SPOSiOL), and its derived chiral ligands. Using the chemical resolution method, the optical SPOSiOL could be obtained in high yield on a gram scale. Preliminary studies indicated that this ligand scaffold has great potential in transition metal-catalyzed asymmetric reactions
手性配体和催化剂发现的手性结构的开发对于不对称催化至关重要。在此,我们报告了以 Si 为中心的螺环骨架、SPirobiphenoxasilin-diol (SPOSiOL) 及其衍生手性配体的简明合成。使用化学拆分方法,可以在克级以高产率获得光学 SPOSiOL。初步研究表明,该配体支架在过渡金属催化的不对称反应中具有巨大潜力。这一发现进一步强调了以 Si 为中心的螺环支架在不对称催化中具有重要价值。
Practical by Ligand Design: A New Class of Monodentate Phosphoramidite Ligands for Rhodium-Catalyzed Enantioselective Hydrogenations
作者:Baoguo Zhao、Zheng Wang、Kuiling Ding
DOI:10.1002/adsc.200606013
日期:2006.6
new class of low-cost and easy-to-prepare monodentate phosphoramidite ligands (CydamPhos) has been developed from readily accessible and cheap trans-1,2-diaminocyclohexane as starting material through a three-step transformation. This type of ligands exhibited excellent enantioseletivities and high activities in rhodium(I)-catalyzed asymmetric hydrogenations of dehydro-α-amino acid methyl esters 9 (ee:
Ni(<scp>ii</scp>)-Catalyzed vinylic C–H functionalization of 2-acetamido-3-arylacrylates to access isotetronic acids
作者:Biswajit Roy、Eshani Das、Avijit Roy、Dipakranjan Mal
DOI:10.1039/d0ob00557f
日期:——
reaction for the synthesis of 4-aryl-substituted isotetronic acids from 2-acetamido-3-arylacrylates via vinylic C-H functionalization is reported. The reaction proceeds through heteroatom guided electrophilic insertion of nickel to the vinylic double bond followed by annulation with dibromomethane. This unconventional route features cascade steps, sole product formation, multiple functional group tolerance
cyclization of N-acetyl enamines and intermolecular cyclocondensation of enamines and nitriles was investigated. The reaction was performed under mild conditions and gave oxazoles and imidazoles, respectively, in moderate to excellent yields. This transformation exhibits good reactivity, selectivity and functional group tolerance. The selectivity of the intra- or intermolecular reaction is dependent on the