Conjugate addition of potassiumtrifluoro(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 alpha-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)
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:
Topology-Based Functionalization of Robust Chiral Zr-Based Metal–Organic Frameworks for Catalytic Enantioselective Hydrogenation
作者:Hong Jiang、Wenqiang Zhang、Xing Kang、Ziping Cao、Xu Chen、Yan Liu、Yong Cui
DOI:10.1021/jacs.0c00637
日期:——
strong acidic and weak basic aqueous solutions. The two flu MOFs featuring the dihydroxyl groups of biphenol in open and large cages, after sequential post-synthetic modification with P(NMe2)3 and [Ir(COD)Cl]2, can be high efficient and recyclable heterogeneous catalysts for hydrogenation of α-dehydroaminoacidesters with up to 98% ee, whereas the three ith MOFs featuring the dihydroxyl groups in small
设计和开发具有高活性和选择性的坚固且多孔的负载型催化剂对于精细化学品和药物的生态友好合成非常重要,但非常具有挑战性。我们在此报告了具有不同拓扑结构的高度稳定的手性 Zr(IV) 基 MOF 的设计和合成,以支持 Ir 配合物并证明其依赖于网络结构的不对称催化性能。在调制合成和等网状扩展策略的指导下,五个具有flu或ith拓扑结构的手性Zr-MOFs由对映纯的1,1'-联苯酚衍生的四羧酸酯接头和Zr6、Zr9或Zr12簇构建而成。所得MOFs在沸水、强酸性和弱碱性水溶液中均表现出较高的化学稳定性。两种以双酚二羟基为特征的开放笼和大笼中的flu MOF,经过P(NMe2)3和[Ir(COD)Cl]2的连续后合成修饰,可以成为高效且可回收的α加氢多相催化剂具有高达 98% ee 的脱氢氨基酸酯,而在小笼中具有二羟基基团的第三个 MOF 不能与 P(NMe2)3 一起安装以支持 Ir 络合物。将 Ir-磷催化剂掺入
A supramolecularly tunable chiral diphosphine ligand: application to Rh and Ir-catalyzed enantioselective hydrogenation
A supramolecularly tunable chiral bisphosphine ligand bearing two pyridyl-containing crown ethers was synthesized and applied in Rh or Ir-catalyzed asymmetric hydrogenations in high yields with excellent ee values (90-99% ee).
Synthesis of novel BINOL-derived chiral bisphosphorus ligands and their application in catalytic asymmetric hydrogenation
作者:Yong-Gui Zhou、Xumu Zhang
DOI:10.1039/b201976k
日期:2002.5.9
Some novel ortho-substituted BINOL-derived bisphosphorous ligands (o-BINAPO and o-NAPHOS) were synthesis from readily available (S)-BINOL; these ligands showed excellent enantioselectivities (up to 99% ee) in Rh(I)-catalyzedasymmetrichydrogenation of functionalizedolefins.