320778-96-9Relevant academic research and scientific papers
Bio-inspired Water-Driven Catalytic Enantioselective Protonation
Park, Si Joon,Hwang, In-Soo,Chang, Young Jun,Song, Choong Eui
, p. 2552 - 2557 (2021/02/01)
Catalytic enantioselective protonation of a prochiral carbanion in water is a common transformation in biological systems, but has been beyond the capability of synthetic chemists since unusually rapid movement of a proton in water leads to uncontrolled racemic protonation. Herein we show a crucial role of water, which enables a highly enantioselective glyoxalase I-mimic catalytic isomerization of hemithioacetals which proceeds via enantioselective protonation of an ene-diol intermediate. The use of on-water condition turns on this otherwise extremely unreactive catalytic reaction as a result of the strengthened hydrogen bonds of water molecules near the hydrophobic reaction mixture. Furthermore, under on-water conditions, especially under biphasic microfluidic on-water conditions, access of bulk water into the enantio-determining transition state is efficiently blocked, consequently enabling the enantioselective introduction of a highly ungovernable proton to a transient enediol intermediate, which mimics the action of enzymes.
Frustrated Lewis acid/Br?nsted base catalysts for direct enantioselective α-amination of carbonyl compounds
Shang, Ming,Wang, Xiaoxu,Koo, Seung Moh,Youn, Jennifer,Chan, Jessica Z.,Yao, Wenzhi,Hastings, Brian T.,Wasa, Masayuki
supporting information, p. 95 - 98 (2017/05/16)
A method for enantioselective direct α-amination reaction catalyzed by a sterically "frustrated" Lewis acid/Br?nsted base complex is disclosed. Cooperative functioning of the Lewis acid and Br?nsted base components gives rise to in situ enolate generation from monocarbonyl compounds. Subsequent reaction with hydrogen-bond activated dialkyl azodicarboxylates delivers α-aminocarbonyl compounds in high enantiomeric purity.
Photoactivity hexahydroquinolinone and preparation method thereof
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Paragraph 0042; 0074, (2017/07/21)
The invention discloses photoactivity hexahydroquinolinone and a preparation method thereof. The photoactivity hexahydroquinolinone is a diastereoisomer consisting of a compound shown as a formula I and a compound shown as a formula II, wherein a diastere
Enantioselectivity switch controlled by N,N′-di- or N,N,N′,N′-tetra-substituted chiral thiophosphorodiamide ligands, structural relatives of thioureas, in catalytic additions of diethylzinc to aldehydes
Yue, Huifeng,Huang, Huayin,Bian, Guangling,Zong, Hua,Li, Fangling,Song, Ling
, p. 170 - 180 (2014/02/14)
We have developed a series of new chiral thiophosphorodiamide ligands derived from (1R,2R)-(+)-1,2-diphenylethylenediamine, which are the structural relatives of thioureas. An investigation into their catalytic properties in asymmetric additions of diethylzinc to aldehydes has shown that N,N,N′,N′-tetra-substituted chiral thiophosphorodiamides can give (R)-secondary alcohols with up to 98% yield and 98% ee, while N,N′-di-substituted chiral thiophosphorodiamides give (S)-secondary alcohols with up to 99% yield and 97% ee values. The enantioselectivity switch is highly efficient with a broad substrate scope. We have also proposed hypothetical reaction pathways, which result in an enantioselectivity switch.
QSAR analysis of the catalytic asymmetric ethylation of ketone using physical steric parameters of chiral ligand substituents
Huang, Huayin,Zong, Hua,Shen, Bin,Yue, Huifeng,Bian, Guangling,Song, Ling
, p. 1289 - 1297 (2014/02/14)
We have demonstrated that a validated QSAR (quantitative structure-activity relationship) model can be constructed between sterimol steric parameters of the N-substituents of chiral 1,2-amino-phosphoramide ligands and the enantiomeric ratios of alcohol products produced in the asymmetric additions of diethylzinc to acetophenone, which is powerful for predicting the steric effects of ligand substituents on enantioselectivities and instructive for ligand optimization.
The first catalytic, enantioselective aza-Henry reaction of an unactivated cyclic imine
Amarasinghe, Nilupa R.,Todd, Matthew H.,Turner, Peter
supporting information, p. 2954 - 2958,5 (2020/10/15)
The aza-Henry reaction is an efficient route to important chiral, vicinal diamines. Reports of the asymmetric version typically use electron-deficient acyclic imines. We report the first example of a catalytic, asymmetric aza-Henry reaction on an unfunctionalized cyclic imine that gives access to enantiopure diamine derivatives under experimentally straightforward conditions. The stereocentre is established through the initial nitromethane addition to the imine. The scalemic intermediate may be trapped through acylation, then crystallized. Copyright
Chiral primary amine catalyzed asymmetric epoxidation of α-substituted acroleins
Li, Jiuyuan,Fu, Niankai,Zhang, Long,Zhou, Pengxin,Luo, Sanzhong,Cheng, Jin-Pei
experimental part, p. 6840 - 6849 (2011/03/19)
1,1-Disubstituted terminal alkenes remain challenging substrates in asymmetric epoxidation reactions. In this study, chiral primary amines are shown to catalyze the asymmetric epoxidation of α-substituted acroleins, a versatile type of 1,1-disubstituted t
A simple primary-tertiary diamine-Bronsted acid catalyst for asymmetric direct aldol reactions of linear aliphatic ketones
Luo, Sanzhong,Xu, Hui,Li, Jiuyuan,Zhang, Long,Cheng, Jin-Pei
, p. 3074 - 3075 (2007/10/03)
Compared with the well-explored enamine catalysis with secondary amines, the development of efficient enamine-based primary amine catalysts has remained as an elusive goal until recently. We present herein that a simple chiral primary-tertiary diamine 1d
An efficient method for the preparation of N,N-disubstituted 1,2-diamines
Mitchell,Finney
, p. 8431 - 8434 (2007/10/03)
C2-Symmetric 1,2-diamines are useful precursors to numerous reagents used in asymmetric synthesis and catalysis. We report here an efficient protocol for converting the two most commonly used trans-1,2-diamines to N,N-disubstituted derivatives, a transformation that simplifies the preparation of non-C2-symmetric diamines. Central to the method is the high-yielding conversion of the diamines to the corresponding monoacetylated derivatives via imidazoline intermediates. (C) 2000 Published by Elsevier Science Ltd.
