10512-92-2Relevant academic research and scientific papers
Highly enantioselective hydrogenation of enamides and itaconic acid in water in the presence of water-soluble rhodium(I) catalyst and sodium dodecyl sulfate
Yonehara, Koji,Ohe, Kouichi,Uemura, Sakae
, p. 9381 - 9385 (1999)
The water-soluble cationic Rh complexes, such as [Rh(α-D- glucopyranosyl-(1,1)-2,3-di-O-(diphenylphosphino)-α-D- glucopyranoside)(cod)]BF4 (1) and [Rh(β-D-glucopyranosyl-(1,1)-2,3-di-O- (diphenylphosphino)-β-D-glucopyranoside)(cod)]BF4 (2) bearing free hydroxy groups, are effective catalysts in the asymmetric hydrogenation of various enamides and itaconic acid (up to 99.9% ee) in water in the presence of sodium dodecyl sulfate (SDS) (7.5 x 10-3 to 1.0 x 10-1 M). The hydrogenation of methyl (Z)-α-acetamidocinnamate in water using the corresponding Rh complexes of triflate (6) and D-camphor-10-sulfonate (7), prepared separately, results in a formation of the product of the same enantioselectivity (48% ee), but the use of SDS can reduce the amount of the catalyst and improve the enantioselectivity to 81% ee. These results show that the counteranions do not directly influence the enantioselectivity. Although the effect of SDS on the enhancement of enantioselectivity remains speculative, the formation of micelle seems to play an important role in improving the enantioselectivity.
Asymmetric hydrogenation of methyl α-benzamido cinnamate in ionic liquid solvent
Boyle, Katherine L.,Lipsky, Emily Beth,Kalberg, Christopher S.
, p. 1311 - 1313 (2006)
The room temperature ionic liquid EMIMOTf was employed as the sole reaction solvent for the asymmetric hydrogenation of methyl α-benzamido cinnamate. Under conditions of 60 psi hydrogen and 50°C for 24 h, near quantitative conversions were observed using
Unusual amino acids V. Asymmetric hydrogenation of (Z)-N-acylaminocinnamic acid derivatives bearing different protective groups.
Kreuzfeld,Dobler,Krause,Facklam
, p. 2047 - 2051 (1993)
The rhodium-catalyzed asymmetric hydrogenation of acylaminocinnamic acid esters, bearing different protective groups, has been investigated in the presence of PROPRAPHOS, BPPM, DIOP, and Ph-β-GLUP as chiral ligands. The influence of the protective group o
Synthesis of a rigid and optically active poly(BINAP) and its application in asymmetric catalysis
Yu, Hong-Bin,Hu, Qiao-Sheng,Pu, Lin
, p. 1681 - 1685 (2000)
The first rigid and sterically regular chiral poly[2,2'- bis(diphenylphosphino)-1,1'-binaphthyl][poly(BINAP)] is synthesized. The application of this polymer ligand in asymmetric hydrogenations is examined. High enantioselectivity for the asymmetric hydro
Novel Water-Soluble Bisphosphinite Chiral Ligands Derived from α,α- And β,β-Trehalose. Application to Asymmetric Hydrogenation of Dehydroamino Acids and Their Esters in Water or an Aqueous/ Organic Biphasic Medium
Yonehara, Koji,Hashizume, Tomohiro,Mori, Kenji,Ohe, Kouichi,Uemura, Sakae
, p. 5593 - 5598 (1999)
Novel 2,3:4,6-di-O-isopropylidene-α-D-glucopyranosyl-(1,1)-4,6-O-isopropylidene- 2,3-di-O-diphenylphosphino-α-D-glucopyranoside (2), 2,3:4,6-di-O-cyclohexylidene-α-D-glucopyranosyl-(1,1)-4,6-O- cyclohexylidene-2,3-di-O-diphenylphosphino-α-D-glucopyranoside (4), and 2,3:4,6-di-O-cyclohexylidene-β-D-glucopyranosyl-(1,1)-4,6-O- cyclohexylidene-2,3-di-O-diphenylphosphino-β-D-glucopyranoside (11) were prepared from the corresponding α,α- or β,β-trehalose. The ligands were transformed into cationic Rh complexes, such as [Rh(α-D-glucopyranosyl-(1,1)-2,3-di-O-diphenylphosphino-α-D- glucopyranoside)(cod)]BF4 (3) and [Rh(β-D-glucopyranosyl-(1,1)-2,3-di-O-diphenylphosphino-β-D- glucopyranoside)(cod)]BF4 (12) bearing free hydroxy groups. These complexes were soluble in water and were efficient catalysts for the asymmetric hydrogenation of dehydroamino acids and their esters in water or an aqueous/organic biphasic medium with high enantioselectivity (up to 99.9% ee). Aqueous biphasic systems offer an easy separation of the aqueous catalyst phase from the product phase and allow recycling of the catalyst phase without the loss of enantioselectivity.
Chiral diphosphites derived from (1R,2R)-trans-1,2-cyclohexanediol: A new class of ligands for asymmetric hydrogenations
Pang, Zeng-Bo,Li, Hai-Feng,Tian, Mi,Wang, Lai-Lai
, p. 1389 - 1393 (2015)
A series of novel chiral diphosphite ligands was easily prepared in a few steps from commercial (1R,2R)-trans-1,2-cyclohexanediol as the chiral source, and successfully employed in the Rh-catalyzed asymmetric hydrogenation of α,β-unsaturated carboxylic ac
Iron-catalyzed oxidative amidation of acylhydrazines with amines
Wang, Yi-Jie,Zhang, Guo-Yu,Shoberu, Adedamola,Zou, Jian-Ping
, (2021/08/18)
A new approach for amide bond formation via a mild and efficient Iron-catalyzed cross-coupling reaction of acylhydrazines and amines using TBHP as oxidant is described. This protocol is compatible with a wide range of amines and acylhydrazines. In addition, the synthetic application of the reaction is presented.
Fast Amide Couplings in Water: Extraction, Column Chromatography, and Crystallization Not Required
Sharma, Sudripet,Buchbinder, Nicklas W.,Braje, Wilfried M.,Handa, Sachin
supporting information, p. 5737 - 5740 (2020/07/14)
In the micelle of PS-750-M, the presence of 3° amides from the surfactant proline linker mimics dimethylformamide, dimethylacetamide, and N-methyl-2-pyrrolidone. The resultant micellar properties enable extremely fast amide couplings mediated by 1-ethyl-3
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.
Dynamic Kinetic Resolution of Azlactones by a Chiral N, N-Dimethyl-4-aminopyridine Derivative Containing a 1,1′-Binaphthyl Unit: Importance of Amide Groups
Mandai, Hiroki,Hongo, Kohei,Fujiwara, Takuma,Fujii, Kazuki,Mitsudo, Koichi,Suga, Seiji
supporting information, p. 4811 - 4814 (2018/08/24)
A dynamic kinetic resolution (DKR) of azlactones in the presence of benzoic acid and a binaphthyl-based N,N-4-dimethylaminopyridine (DMAP) derivative 1i having two amide groups at the 3,3′-positions of a binaphthyl unit is developed. The reaction proceeded smoothly with a wide range of azlactones to provide α-amino acid derivatives with good to high enantiomeric ratios (er's). A multigram-scale reaction (2.5 g) for the DKR of azlactone 2d was also demonstrated, and the resulting product was converted to unnatural α-amino acid 6d′.
