The Synthesis of Chiral α-Aryl α-Hydroxy Carboxylic Acids via RuPHOX-Ru Catalyzed Asymmetric Hydrogenation
A ruthenocenyl phosphino-oxazoline-ruthenium complex (RuPHOX?Ru) catalyzed asymmetric hydrogenation of α-aryl keto acids has been successfully developed, affording the corresponding chiral α-aryl α-hydroxy carboxylic acids in high yields and with up to 97% ee. The reaction could be performed on a gram scale with a relatively low catalyst loading (up to 5000 S/C) and the resulting products can be transformed to several chiral building blocks, biologically active compounds and chiral drugs. (Figure presented.).
Guo, Huan,Li, Jing,Liu, Delong,Zhang, Wanbin
p. 3665 - 3673
(2017/09/11)
Convenient divergent strategy for the synthesis of TunePhos-type chiral diphosphine ligands and their applications in highly enantioselective Ru-catalyzed hydrogenations
(Chemical Equation Presented) A convenient, divergent strategy for the synthesis of a series of modular and fine-tunable C3-TunePhos-type chiral diphosphine ligands and their applications in highly efficient Rucatalyzed asymmetric hydrogenations were explored. Up to 97 and 99% ee values were achieved for the enantioselective synthesis of β-methyl chiral amines and α-hydroxy acid derivatives, respectively.
Sun, Xianfeng,Zhou, Le,Li, Wei,Zhang, Xumu
p. 1143 - 1146
(2008/09/18)
Catalytic asymmetric reaction with water: Enantioselective synthesis of α-hydroxyesters by a copper-carbenoid O-H insertion reaction
(Chemical Equation Presented) Taking on water: A novel catalytic asymmetric metal-carbenoid insertion reaction with water has been developed with copper complexes of chiral spiro bisoxazoline ligands as catalysts. This reaction provides an efficient and practical procedure for preparing chiral α-hydroxyesters and acids starting from readily available materials in high yields and enantioselectivities. BArF- = [B{3,5-(CF3)2C6H3)} 4]-.
Zhu, Shou-Fei,Chen, Chao,Cai, Yan,Zhou, Qi-Lin
p. 932 - 934
(2008/09/20)
Highly enantioselective hydrogenation of α-keto esters catalyzed by Ru-tunephos complexes
Various enantiomerically pure α-hydroxy esters were synthesized by asymmetric hydrogenation of α-keto esters catalyzed by Ru-C n-Tunephos complex. Up to 97.1% ee has been achieved for both α-aryl and α-alkyl substituted α-keto esters. Georg Thieme Verlag Stuttgart.
Wang, Chun-Jiang,Sun, Xianfeng,Zhang, Xumu
p. 1169 - 1172
(2007/10/03)
Resolution of Mandelic Acids by Lipase-catalysed Transesterifications in Organic Media: Inversion of Enantioselectivity mediated by the Acyl Donor
The lipase-catalysed highly enantioselective deacylation and acylation of mandelic acid derivatives and the inversion of enantioselectivity mediated by the acyl donor are described.
Enantioselectivity of carbonic anhydrase catalyzed hydrolysis of mandelic methyl esters
We report the first enantioselective hydrolysis of esters catalyzed by caebonic anhydrase.We found that mandelic methyl esters are good substrates for carbonic anhydrase.The R enantiomers are better substrates and enantiomeric excess values are moderate (40-51percent).
Chenevert, Robert,Letourneau, Martin
p. 314 - 316
(2007/10/02)
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