30836-32-9Relevant academic research and scientific papers
An Atropos Biphenyl Bisphosphine Ligand with 2,2′-tert-Butylmethylphosphino Groups for the Rhodium-Catalyzed Asymmetric Hydrogenation of Enol Esters
Jia, Jia,Fan, Dongyang,Zhang, Jian,Zhang, Zhenfeng,Zhang, Wanbin
, p. 3793 - 3800 (2018/09/20)
This is an update of our previous work concerning the development of Atropos biphenyl bisphosphine ligands. An unexpected Atropos structural property was confirmed by single crystal X-ray diffraction and this result is consistent with the computational calculations described in our previous work. This P-stereogenic bisphosphine ligand possessing a biphenyl backbone and 2,2′-tert-butylmethylphosphino groups has been applied to the Rh-catalyzed asymmetric hydrogenation of enol esters, which has not been widely studied and can be used for the synthesis of several important bioactive compounds. Although there is room for further improvement in enantioselectivity, the results reported herein provide a further understanding of such types of ligands. (Figure presented.).
The assignment of the configuration for α-hydroxy acid esters using a CEC strategy
Peng, Ruixue,Lin, Lili,Zhang, Yuheng,Wu, Wangbin,Lu, Yan,Liu, Xiaohua,Feng, Xiaoming
, p. 5258 - 5262 (2016/07/06)
A simple and efficient 1H NMR method for determining the absolute configuration of chiral α-hydroxy acid esters using a competing enantioselective conversion (CEC) strategy was developed. The α-hydroxy acid esters were acylated in the presence
Kinetic resolution of mandelate esters via stereoselective acylation catalyzed by lipase PS-30
Chen, Peiran,Yang, Wenhong
supporting information, p. 2290 - 2294 (2014/04/17)
By using lipase PS-30 as catalyst, the kinetic resolution of a series of racemic mandelate esters has been achieved via stereoselective acylation. The value of kinetic enantiomeric ratio (E) reached up to 197.5. Substituent effect is briefly discussed.
Hydrogen bonding makes a difference in the rhodium-catalyzed enantioselective hydrogenation using monodentate phosphoramidites
Liu, Yan,Sandoval, Christian A.,Yamaguchi, Yoshiki,Zhang, Xue,Wang, Zheng,Kato, Koichi,Ding, Kuiling
, p. 14212 - 14213 (2008/02/09)
A new generation of monodentate phosphoramidite ligands bearing a primary amine moiety was found to display comparable or better efficiency than bisphosphines in the Rh-catalyzed asymmetric hydrogenation of challenging substrates, such as (Z)-methyl α-ace
Kinetic resolution of α-acetoxy N-acyl oxazolidinethiones by a chiral O-nucleophilic acyl transfer catalyst
Nolle, Gregory T.,Sammakia, Tarek,Steel, Peter J.
, p. 13502 - 13503 (2007/10/03)
The kinetic resolution of α-acetoxy N-acyl oxazolidinethiones using the chiral, nonracemic O-nucleophilic acyl transfer catalyst 8 is described. The reaction proceeds on a variety of substrates in excellent yields, with s-factors ranging from 17 to 31. Copyright
A Practical Method for Optical Resolution of Racemic Alcohols or Esters via Lipase-Catalyzed Transformation and Sulfation
Yamano, Toru,Kikumoto, Fumio,Yamamoto, Shozo,Miwa, Katsuhiko,Kawada, Mitsuru,Ito, Tatsuya,Ikemoto, Tomomi,Tomimatsu, Kiminori,Mizuno, Yukio
, p. 448 - 449 (2007/10/03)
Optically active esters were conveniently obtained from the corrasponding racemic alcohols or esters by lipase-catalyzed transformation, followed by sulfation. Sulfation by sulfurtrioxide pyridine complex enabled facile isolation of optically active esters by extraction instead of laborious column chromatography. The method would be especially adventageous on a large scale.
ISOLATION OF β-PHENYLLACTIC ACID RELATED COMPOUNDS FROM PSEUDOMONAS SYRINGAE
Evidente, Antonio,Iacobellis, Nicola S.,Scopa, Antonio,Surico, Giuseppe
, p. 1491 - 1497 (2007/10/02)
Three metabolites, weakly phytotoxic on apple and bean leaves, have been isolated from Pseudomonas syringae pv papulans culture filtrates and their structures established by spectroscopic analysis.The trivial names of papuline, o-hydroxynitropapuline and papulinone were assigned to the three active substances.Papuline was the methylester of β-phenyllactic acid, and o-hydroxynitropapuline was its meta-hydroxy-para-nitro disubstituted derivative.Papulinone, a new β-lactone structurally related to β-phenyllactic acid, was identified as 4-(1-hydroxy-2-phenylethyl)-4-carbomethoxyoxyetan-2-one.
Substitution of 2-(Sulfonyloxy)carboxylates with Oxygene and Sulfur Nucleophiles without Racemization
Burkard, Ulrike,Effenberger, Franz
, p. 1594 - 1612 (2016/06/15)
The ethyl 2-(sulfonyloxy)propionates (S)-1a-c react with phenolates formed from 2 and with carboxylates 8 to give the respective 2-(aryloxy)- (R)-3 and 2-(acyloxy)propionates (R)-9 with inversion of configuration.Due to the high leaving tendency of the triflate group, (S)-1a generally give higher yields of substitution products under milder conditions than the corresponding mesylate (S)-1b and tosylate (S)-1c.In the case of the reaction of malic and succinic acid derivatives only the triflate (S)-10a is converted to the acyloxy compounds (R)-12 with carboxylates 8 atlow temperature (-45 deg C); with the mesylates 10b and the bromide 10d only elimination is observed.Mercaptides and thiophenolates formed from 17 react with (S)-1a-c analogously.With potassium thiocyanate 1a,b react almost exclusively to give the thiocyanate 19; only traces of the corresponding isothiocyanate 20 are obtained.
