60676-51-9Relevant academic research and scientific papers
Asymmetric hydroformylation of N-acyl 1-aminoacrylic acid derivatives by rhodium/chiral diphosphine catalysts
Gladiali,Pinna
, p. 623 - 632 (1991)
The asymmetric hydroformylation of N-acylaminoacrylic acid esters 1 is efficiently catalysed by HRh(CO)(PPh3)3 in the presence of DIOP and related diphosphines as chiral ligands. The reaction is completely regioselective and affords
Concise synthesis and applications of enantiopure spirobiphenoxasilin-diol and its related chiral ligands
Liu, Tao,Wang, Biqin,Wang, Peng,Wu, Yichen,Xu, Wen-Qiang,Yang, Lei
supporting information, p. 13365 - 13368 (2021/12/17)
The development of chiral architectures for chiral ligand and catalyst discovery is essential for asymmetric catalysis. 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. This finding further highlights that the Si-centered spirocyclic scaffolds are of great value in asymmetric catalysis. This journal is
Topology-Based Functionalization of Robust Chiral Zr-Based Metal-Organic Frameworks for Catalytic Enantioselective Hydrogenation
Jiang, Hong,Zhang, Wenqiang,Kang, Xing,Cao, Ziping,Chen, Xu,Liu, Yan,Cui, Yong
, p. 9642 - 9652 (2020/07/02)
The design and development of robust and porous supported catalysts with high activity and selectivity is extremely significant but very challenging for eco-friendly synthesis of fine chemicals and pharmaceuticals. We report here the design and synthesis of highly stable chiral Zr(IV)-based MOFs with different topologies to support Ir complexes and demonstrate their network structures-dependent asymmetric catalytic performance. Guided by the modulated synthesis and isoreticular expansion strategy, five chiral Zr-MOFs with a flu or ith topology are constructed from enantiopure 1,1′-biphenol-derived tetracarboxylate linkers and Zr6, Zr9, or Zr12 clusters. The obtained MOFs all show high chemical stability in boiling water, strongly acidic, and weakly basic aqueous solutions. The two flu MOFs featuring the dihydroxyl groups of biphenol in open and large cages, after sequential postsynthetic modification with P(NMe2)3 and [Ir(COD)Cl]2, can be highly efficient and recyclable heterogeneous catalysts for hydrogenation of α-dehydroamino acid esters with up to 98% ee, whereas the three ith MOFs featuring the dihydroxyl groups in small cages cannot be installed with P(NMe2)3 to support the Ir complex. Incorporation of Ir-phosphorus catalysts into Zr-MOFs leads to great enhancement of their chemical stability, durability, and even stereoselectivity. This work therefore not only advances Zr-MOFs as stable supports for labile metal catalysts for heterogeneous asymmetric catalysis but also provides a new insight into how highly active chiral centers can result due to the framework topology.
Silver-Promoted Direct Phosphorylation of Bulky C(sp2)-H Bond to Build Fully Substituted β-Phosphonodehydroamino Acids
Cao, Hao-Qiang,Liu, Hao-Nan,Liu, Zhe-Yuan,Qiao, Baokun,Zhang, Fa-Guang,Ma, Jun-An
, p. 6414 - 6419 (2020/09/02)
A general and practical cross-dehydrogenative coupling protocol between readily available trisubstituted α,β-dehydro α-amino carboxylic esters and H-phosphites is described. This C(sp2)-H phosphorylation reaction proceeds with absolute Z-selectivity promoted by silver salt in a radical relay manner. The bulky tetrasubstituted β-phosphonodehydroamino acids were obtained in grams and added new modules to the toolkit for peptide modifications.
Nickel-Catalyzed Asymmetric Hydrogenation of 2-Amidoacrylates
Chen, Jianzhong,Gridnev, Ilya D.,Hu, Yawen,Li, Bowen,Zhang, Wanbin,Zhang, Zhenfeng
supporting information, p. 5371 - 5375 (2020/02/15)
Earth-abundant nickel, coordinated with a suitable chiral bisphosphine ligand, was found to be an efficient catalyst for the asymmetric hydrogenation of 2-amidoacrylates, affording the chiral α-amino acid esters in quantitative yields and excellent enantioselectivity (up to 96 % ee). The active catalyst component was studied by NMR and HRMS, which helped us to realize high catalytic efficiency on a gram scale with a low catalyst loading (S/C=2000). The hydrogenated products could be simply converted into chiral α-amino acids, β-amino alcohols, and their bioactive derivatives. Furthermore, the catalytic mechanism was investigated using deuterium-labeling experiments and computational calculations.
Ni(ii)-Catalyzed vinylic C-H functionalization of 2-acetamido-3-arylacrylates to access isotetronic acids
Das, Eshani,Mal, Dipakranjan,Roy, Avijit,Roy, Biswajit
supporting information, p. 3697 - 3706 (2020/06/03)
A ligand-free Ni(ii)-catalyzed cascade annulation reaction for the synthesis of 4-aryl-substituted isotetronic acids from 2-acetamido-3-arylacrylatesviavinylic 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, low cost of catalysts and reagents, and readily available starting materials. Using this method, various aryl-substituted isotetronic acids have been synthesized which are biologically relevant. The annulation of 2-acetamido-3-arylacrylates has also been assessed with 1,2-dichloroethane, which resulted in the rearranged annulated products of 5-methyl substituted isotetronic acids.
Novel biferrocene-based phosphoramidite ligands: The combination of a rather unexplored chiral backbone and a privileged ligand scaffold
Kimpe,Janssens,Bert,Wackens,Goeman,Van der Eycken
supporting information, (2019/10/16)
A small library of novel chiral monodentate phosphoramidite ligands, characterized by a dihydroazepine-biferrocene backbone was prepared. In order to obtain this biferrocene substructure, a mild and efficient homocoupling was developed. This allowed to synthesize the dihydroazepine ligand precursor and the phosphoramidite ligands with good overall yields and high enantiomeric excess. These ligands were successfully tested in a rhodium(I)-catalyzed hydrogenation of activated olefins.
Hypervalent iodane mediated reactions of: N -acetyl enamines for the synthesis of oxazoles and imidazoles
Xu, Kang,Yang, Ruiqi,Yang, Shuang,Jiang, Cheng,Ding, Zhenhua
supporting information, p. 8977 - 8981 (2019/10/28)
A hypervalent iodane reagent used for the intramolecular 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 structure of N-acetyl enamines.
An Atropos Chiral Biphenyl Bisphosphine Ligand Bearing Only 2,2′-Substituents and Its Application in Rh-Catalyzed Asymmetric Hydrogenation
Jia, Jia,Ling, Zheng,Zhang, Zhenfeng,Tamura, Ken,Gridnev, Ilya D.,Imamoto, Tsuneo,Zhang, Wanbin
supporting information, p. 738 - 743 (2017/12/26)
An atropos chiral biphenyl bisphosphine ligand bearing only 2,2′-substituents was rationally designed and easily synthesized utilizing a bulky chiral t-butylmethylphosphino block. Computational results showed a large difference in the free energies betwee
Temperature-controlled bidirectional enantioselectivity in a dynamic catalyst for asymmetric hydrogenation
Storch, Golo,Trapp, Oliver
supporting information, p. 3580 - 3586 (2015/03/18)
Asymmetric catalysis using enantiomerically pure catalysts is one of the most widely used methods for the preparation of enantiomerically pure compounds. The separate synthesis of both enantiomerically pure compounds requires tedious and time-consuming pr
