89015-27-0Relevant articles and documents
Chiral-at-Iron Catalyst: Expanding the Chemical Space for Asymmetric Earth-Abundant Metal Catalysis
Hong, Yubiao,Jarrige, Lucie,Harms, Klaus,Meggers, Eric
supporting information, p. 4569 - 4572 (2019/03/19)
A new class of chiral iron catalysts is introduced that contains exclusively achiral ligands with the overall chirality being the result of a stereogenic iron center. Specifically, iron(II) is cis-coordinated to two N-(2-pyridyl)-substituted N-heterocycli
Rhodium-Catalyzed Asymmetric Addition of Arylboronic Acids to Glyoxylates: Access to Optically Active Substituted Mandelic Acid Esters
Chen, Diao,Liu, Jian-Guo,Xu, Ming-Hua,Zhang, Xu
supporting information, p. 1693 - 1697 (2019/08/26)
A rhodium-catalyzed enantioselective addition of glyoxylates to arylboronic acids promoted by a simple chiral sulfinamide-based olefin ligand under mild reaction conditions is described. The reaction provides access to a variety of optically active substituted mandelic acid esters in good yields with up to 83percent ee. The catalytic system is also applicable to pyruvate addition. The synthetic utility of this method is highlighted by a formal synthesis of the antiplatelet drug clopidogrel.
Catalytic asymmetric Meerwein-Ponndorf-Verley reduction of glyoxylates induced by a chiral N,N′-dioxide/Y(OTf)3 complex
Wu, Wangbin,Zou, Sijia,Lin, Lili,Ji, Jie,Zhang, Yuheng,Ma, Baiwei,Liu, Xiaohua,Feng, Xiaoming
, p. 3232 - 3235 (2017/03/20)
An asymmetric Meerwein-Ponndorf-Verley (MPV) reduction of glyoxylates was for the first time accomplished via an N,N′-dioxide/Y(OTf)3 complex with aluminium alkoxide and molecular sieves (MSs) as crucial additives. A variety of optically active α-hydroxyesters were obtained with excellent results. A possible reaction mechanism was proposed based on the experiments.
Dual pathway for the asymmetric transfer hydrogenation of α-ketoimides to chiral α-hydroxy imides or chiral α-hydroxy esters
Zhao, Qiankun,Zhao, Yuxi,Liao, Hang,Cheng, Tanyu,Liu, Guohua
, p. 412 - 416 (2016/02/05)
In an enantioselective reaction, we expect to obtain two types of chiral products through a controllable strategy in asymmetric catalysis. Herein, we develop Ru-catalysed asymmetric transfer hydrogenation of α-ketoimides to realise an enantioselective construction of chiral α-hydroxy imides or chiral α-hydroxy esters. The transformation of α-ketoimides catalysed by (S,S)-[RuCl(η6-mesitylene)diamine] can afford various chiral α-hydroxy imides with high yields and enantioselectivities, whereas that catalysed by (S,S)-[RuCl(η6-hexamethylbenzene)diamine] gives the desirable chiral α-hydroxy esters through a slight adjustment of the reaction conditions. The method described here is a controllable organic transformation with sodium formate as a hydrogen source under mild reaction conditions, and the benefit of this transformation is that various chiral α-hydroxy imides or α-hydroxy esters can be obtained selectively from α-ketoimides. Selective directive: An enantioselective transformation in the Ru-catalyzed asymmetric transfer hydrogenation of α-ketoimides to chiral α-hydroxy imides or α-hydroxy esters is developed. The transformation of α-ketoimides catalyzed by (S,S)-[RuCl(η6-mesitylene)diamine] can afford various chiral α-hydroxy imides with high yields and enantioselectivities, whereas that catalyzed by (S,S)-[RuCl(η6-hexamethylbenzene)diamine] give desirable chiral α-hydroxy esters through a slight adjustment of reaction conditions.
Chiral N,N′-dioxide-FeCl3 complex-catalyzed asymmetric intramolecular Cannizzaro reaction
Wu, Wangbin,Liu, Xiaohua,Zhang, Yuheng,Ji, Jie,Huang, Tianyu,Lin, Lili,Feng, Xiaoming
supporting information, p. 11646 - 11649 (2015/07/15)
An environmentally benign catalyst, the N,N′-dioxide-FeCl3 complex, has been developed for the asymmetric intramolecular Cannizzaro reaction. Aryl and alkyl glyoxal monohydrates were applied to obtain α-hydroxy acid esters with excellent results. Deuterium-label and control experiments shed light on the reaction mechanism.
Enantio- and chemoselective Br?nsted-acid/Mg(nBu) 2 catalysed reduction of α-keto esters with catecholborane
Enders, Dieter,St?ckel, Bianca A.,Rembiak, Andreas
supporting information, p. 4489 - 4491 (2014/04/17)
The first enantio- and chemoselective Br?nsted-acid catalysed reduction of α-keto esters with catecholborane has been developed. The α-hydroxy esters were obtained under mild reaction conditions in virtually quantitative yields and excellent enantioselectivities. With slight modifications both enantiomers can be obtained without any loss of selectivity. This journal is the Partner Organisations 2014.
A highly efficient and enantioselective intramolecular cannizzaro reaction under TOX/Cu(II) catalysis
Wang, Pan,Tao, Wen-Jie,Sun, Xiu-Li,Liao, Saihu,Tang, Yong
, p. 16849 - 16852 (2013/12/04)
An asymmetric intramolecular Cannizzaro reaction of aryl and alkyl glyoxals with alcohols has been realized with an unprecedented high level of enantioselectivity, on the basis of a newly developed congested TOX ligand and a gradual liberation protocol of active glyoxals from glyoxal monohydrates. Preliminary results suggested a mechanism of enantioselective addition of alcohols to glyoxals contributing most to the stereoselectivity, other than by the dynamic kinetic resolution of hemiacetal intermediates.
A homochiral porous metal-organic framework for enantioselective adsorption of mandelates and photocyclizaton of tropolone ethers
Peng, Yongwu,Gong, Tengfei,Cui, Yong
supporting information, p. 8253 - 8255 (2013/09/12)
A chiral porous metal-organic framework of an axially C2- symmetric 1,1′-biphenol ligand is constructed and can be used as a solid-state host to enanioselectively adsorb mandelates with up to 93.1% ee and to entrap achiral tropolone ethers and
Asymmetric aerobic oxidation of α-hydroxy acid derivatives catalyzed by reusable, polystyrene-supported chiral N-salicylidene oxidovanadium tert-leucinates
Salunke, Santosh B.,Babu, N.Seshu,Chen, Chien-Tien
, p. 1234 - 1240 (2011/06/26)
The direct immobilization of two different C-5-propargyl ether-modified, chiral N-salicylidene vanadyl(V) tert-leucinates onto 4-azidomethyl-substituted polystyrene by click chemistry was examined. Among the eight different solvents investigated, the resulting polystyrene-supported catalysts promote the asymmetric, aerobic oxidation of α-hydroxy (thio)esters and amides with enantioselectivities of up to 99% ee (selectivity factor up to 41) in chloroform. These polystyrene-supported catalysts can be readily recovered by filtration and reused for at least four consecutive runs without discernible loss of reactivity and enantioselectivity.
Chiral cobalt-catalyzed enantioselective aerobic oxidation of α-hydroxy esters
Alamsetti, Santosh Kumar,Sekar, Govindasamy
supporting information; experimental part, p. 7235 - 7237 (2010/12/24)
A chiral cobalt-catalyzed enantioselective aerobic oxidative kinetic resolution of (±)-α-hydroxy esters, using molecular oxygen as a sole oxidant, is reported and a maximum of selectivity factor (s) 31.9 was achieved with >99% enantiomeric excess for unreacted α-hydroxy esters.
