156197-79-4Relevant academic research and scientific papers
Preparation and confinement effect of a heterogeneous 9-amino-9-deoxy-epi- cinchonidine organocatalyst for asymmetric aldol addition in aqueous medium
Wang, Wei,Ma, Xuebing,Wan, Jingwei,Cao, Jun,Tang, Qian
, p. 5715 - 5726 (2012)
A series of novel porous zirconium phosphonate-supported 9-amino-9-deoxy-epi-cinchonidines of general formulae Zr(OH) 4-2x(O3PR)x·nH2O and Zr(HPO4)2-x(O3PR)x·nH 2
Organocatalytic asymmetric aldol reaction using protonated chiral 1,2-diamines
Shim, Jae Ho,Kim, Min-Joon,Lee, Ji Yeon,Kim, Kyoung Hoon,Ha, Deok-Chan
supporting information, (2020/08/14)
Organic-catalyzed stereoselective reactions have gained attention because they avoid the problems associated with metal catalysts, but existing catalysts based on proline have limitations. Therefore, (R,R)-(+)-1,2-diphenylethylenediamine (DPEN) was select
Enantiopure cis- and trans-2-(2-Aminocyclohexyl)phenols: Effective Preparation, Solid-State Characterization, and Application in Asymmetric Organocatalysis
Tezeren, Mustafa A.,Ye?il, Tolga A.,Zorlu, Yunus,Tilki, Tahir,Ertürk, Erkan
, p. 7017 - 7032 (2018/12/13)
Effective synthesis of cis- and trans-2-(2-methoxyphenyl)cyclohexylamine as well as their multigram-scale optical resolution by diastereomeric salt formation with dibenzoyl tartaric acid have been described. Assignment of absolute configurations to the enantiomers has been made by X-ray crystallography. Starting from the resolved precursor, diverse aminoalkylphenols (AAPs) having primary, secondary, and tertiary amine group as well as a quaternary ammonium phenol have been prepared as potential bifunctional organocatalysts based on the cyclohexane backbone. We furthermore report herein that AAPs carrying a primary amine and a phenolic hydroxyl group can catalyze the direct aldol reaction with high activity and setereoselectivity, and thus up to 97 % yield, 90:10 syn/anti diastereomeric ratio, and 80 % enantiomeric excess can be achieved.
Monofunctional primary amine: A new class of organocatalyst for asymmetric Aldol reaction
Vanlaldinpuia, Khiangte,Bora, Porag,Bez, Ghanashyam
, p. 301 - 312 (2017/03/23)
A new class of organocatalysts involving a primary amine as the only functional group is developed for catalytic asymmetric aldol reaction of cyclohexanone/cyclopentanone with various aryl aldehydes in the presence of benzoic acid as an additive at ?10su
Multifunctional heterocyclic scaffolds for hybrid Lewis acid/Lewis base catalysis of carbon–carbon bond formation
Wiedenhoeft, Dennis,Benoit, Adam R.,Wu, Yibiao,Porter, Jacob D.,Meyle, Elisia,Yeung, Teresa H.W.,Huff, Raechel,Lindeman, Sergey V.,Dockendorff, Chris
, p. 3905 - 3916 (2016/07/06)
Several new classes of hybrid catalysts have been synthesized by tethering heterocyclic metal (Lewis acid) chelating scaffolds to several different amines capable of facilitating enamine catalysis. Oxazole, thiazole, and imidazole-based chiral precatalyst
Enantioselective direct aldol reactions promoted by phosphine oxide aziridinyl phosphonate organocatalysts
Dogan, ?zdemir,Tan, Duygu
, p. 1348 - 1353 (2015/11/25)
A series of phosphine oxide based chiral Lewis bases were screened as organocatalysts for silicon tetrachloride mediated direct asymmetric aldol reactions between cyclohexanone and various aromatic aldehydes. One of the phosphine oxide-aziridinyl phosphon
Solvent-effects tuning the catalytic reactivity of prolinamides in asymmetric aldol reactions
Huang, Xiang-Rong,Liu, Qi,Wang, Jing,Xiao, Jun-An,Yang, Hua
, p. 1590 - 1598 (2015/01/09)
Novel prolinamides were prepared and applied as organocatalysts in the asymmetric aldol reaction. Stable imidazolidinones were formed between prolinamides and aromatic aldehydes in organic solvents. It was found that aqueous conditions can significantly suppress the formation of the unwanted imidazolidinone intermediate and improve the catalytic activity of the prolinamides. As a consequence, high chemical yields (up to 99%) and good diastereoselectivity (up to >20:1 dr) and enantioselectivity (up to 95% ee) were achieved in 2-Me-THF or brine. This strategy could serve as a general solution to enhance the performance of prolinamides as organocatalysts.
Asymmetric aldol reaction catalyzed by a chiral phosphine-silver complex
Yanagisawa, Akira,Miyake, Ryoji,Yoshida, Kazuhiro
, p. 4248 - 4253 (2014/07/21)
A catalytic asymmetric aldol reaction of alkenyl trihaloacetates or a γ,δ-unsaturated δ-lactone with aldehydes or an α-keto ester was achieved by using a 2,2′-bis(diphenylphosphino)-1,1′- binaphthyl·silver trifluoromethanesulfonate complex as the chiral p
Study of asymmetric aldol and Mannich reactions catalyzed by proline-thiourea host-guest complexes in nonpolar solvents
Demir, Ayhan Sitki,Basceken, Sinan
, p. 515 - 525 (2013/06/26)
A proline-thiourea host-guest complex has been described as a good catalyst for asymmetric reactions such as aldol and Mannich reactions. High stereoselectivities were obtained under optimal conditions. Thiourea was observed to have an important effect on the reactivity and selectivity, even in an unconventional nonpolar reaction medium and without the need to utilize low temperatures. This proline-thiourea host-guest system has the ability to participate in a hydrogen bonding network.
Study of the lanthanide-catalyzed, aqueous, asymmetric Mukaiyama aldol reaction
Mei, Yujiang,Averill, Derek J.,Allen, Matthew J.
scheme or table, p. 5624 - 5632 (2012/09/05)
The development of efficient methods for the asymmetric Mukaiyama aldol reaction in aqueous solution has received great attention. We have developed a new series of chiral lanthanide-containing complexes that produce Mukaiyama aldol products with outstanding enantioselectivities. In this paper, we describe an optimized ligand synthesis, trends in stereoselectivity that result from changing lanthanide ions, and an exploration of substrate scope that includes aromatic and aliphatic aldehydes and silyl enol ethers derived from aromatic and aliphatic ketones.
