1387581-28-3Relevant articles and documents
Bio-inspired Water-Driven Catalytic Enantioselective Protonation
Park, Si Joon,Hwang, In-Soo,Chang, Young Jun,Song, Choong Eui
supporting information, 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.
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.
