35190-17-1Relevant academic research and scientific papers
Isostructurality of quinoxaline crystal phases: The interplay of weak hydrogen bonds and halogen bonding
Bowen, Richard D.,Fenwick, Nathan W.,Saidykhan, Amie,Seaton, Colin C.,Telford, Richard
, p. 7108 - 7117 (2021/10/26)
Tailoring the physical properties of molecular crystals though the construction of solid solutions requires the existence of isostructural crystals. Simple substitutions of a given molecular framework can give a range of different crystal structures. A se
Preparation and Application of Silica Films Supported Imidazolium-Based Ionic Liquid as Efficient and Recyclable Catalysts for Benzoin Condensations
Qian, Cunwei,Yao, Changsheng,Yang, Liujun,Yang, Bo,Liu, Shuchun,Liu, Zongtang
, p. 1389 - 1396 (2019/11/21)
Abstract: Two silica films -immobilized imidazolium-based ionic liquids (TMICl @silica films) were prepared, characterized and utilized as efficient catalysts for the benzoin reaction. Combined characterization results from FT-IR, elemental analysis, N2 adsorption–desorption isotherms and SEM, suggested that the imidazolium-based ionic liquids were successfully immobilized on the silica films. Moreover, the catalytic performance tests demonstrated that silica films immobilized imidazolium-based ionic liquids (ILs) exhibited excellent activity for the benzoin reactions of aromatic aldehydes. The influence of catalyst concentration, temperature and reaction duration on the catalytic activity were investigated by employing 0.7TMICl @silica film(catalyst C) as the catalyst. The results also showed that the benzoin condensations of aromatic aldehydes could give desired products with satisfactory yields under the optimized conditions. Additionally, the catalyst can be effortlessly separated by filtration and reused more than five times without significant loss of activity. Graphic Abstract: [Figure not available: see fulltext.]
The Direct Conversion of α-Hydroxyketones to Alkynes
Ghiringhelli, Francesca,Nattmann, Lukas,Bognar, Sabine,Van Gemmeren, Manuel
, p. 983 - 993 (2019/01/24)
Alkynes are highly important functional groups in organic chemistry, both as part of target structures and as versatile synthetic intermediates. In this study, a protocol for the direct conversion of α-hydroxyketones to alkynes is reported. In combination with the variety of synthetic methods that generate the required starting materials by forming the central C-C bond, it enables a highly versatile fragment coupling approach toward alkynes. A broad scope for this novel transformation is shown alongside mechanistic insights. Furthermore, the utility of our protocol is demonstrated through its application in concert with varied α-hydroxyketone syntheses, giving access to a broad spectrum of alkynes.
NaBrO3/bmim[HSO4]: a versatile system for the selective oxidation of 1,2-diols, α-hydroxyketones, and alcohols
Khurana, Jitender M.,Lumb, Anshika,Chaudhary, Ankita
, p. 381 - 386 (2017/02/10)
Abstract: Sodium bromate with bmim[HSO4] has been found to be an excellent oxidizing agent in aqueous medium. NaBrO3:bmim[HSO4] oxidized 1,2-diols, α-hydroxyketones, and alcohols to the corresponding carbonyl compounds in excellent yields. This method offers advantages such as low cost reagents, aqueous reaction conditions, moderate temperatures and short reaction times and hence environmentally benign reaction. Moreover, the ionic liquid bmim[HSO4] could be recycled for at least three times without loss of significant activity. Graphical abstract: [Figure not available: see fulltext.]
Palladium-Catalyzed Chemo- and Enantioselective C?O Bond Cleavage of α-Acyloxy Ketones by Hydrogenolysis
Chen, Jianzhong,Zhang, Zhenfeng,Liu, Delong,Zhang, Wanbin
supporting information, p. 8444 - 8447 (2016/07/19)
A chemoselective C?O bond cleavage of the ester alkyl side-chain of α-acyloxy ketones was realized for the first time by a highly efficient palladium-catalyzed hydrogenolysis (S/C=6000, the highest catalytic efficiency by far). Furthermore, a kinetic resolution of α-acyloxy ketones was first developed by enantioselective hydrogenolysis with good yields and up to 99 % ee.
A new protocol for one-pot synthesis of tetrasubstituted pyrroles using tungstate sulfuric acid as a reusable solid catalyst
Farahi, Mahnaz,Davoodi, Mahdiyeh,Tahmasebi, Mina
, p. 1582 - 1584 (2018/03/22)
A variety of tetrasubstituted pyrroles were synthesized in good yields in a one-pot, three-component reaction of α-hydroxyketones, malononitrile, and ammonium acetate using tungstate sulfuric acid (TSA) under solvent-free conditions.
Highly enantioselective hydrogenation of o-alkoxy tetrasubstituted enamides catalyzed by a Rh/(R, S)-josiphos catalyst
Meng, Jingjing,Gao, Min,Lv, Hui,Zhang, Xumu
supporting information, p. 1842 - 1845 (2015/04/27)
Rh/(R,S)-JosiPhos complex-catalyzed asymmetric hydrogenation of o-alkoxy tetrasubstituted enamides has been achieved, and it furnished a set of β-amino alcohol analogues in high yields and excellent enantiomeric excesses (>99% conversion, up to 99% ee).This method provides valuable chiral building blocks in chiral pharmaceuticals and useful motifs for catalysts.
Chemoselective and repetitive intermolecular cross-acyloin condensation reactions between a variety of aromatic and aliphatic aldehydes using a robust N-heterocyclic carbene catalyst
Jin, Ming Yu,Kim, Sun Min,Mao, Hui,Ryu, Do Hyun,Song, Choong Eui,Yang, Jung Woon
supporting information, p. 1547 - 1550 (2014/03/21)
We found that chemoselectivity of the crossed acyloin product is controlled by the adjustment of the aromatic aldehyde/aliphatic aldehyde ratio. Moreover, we observed the persistent catalytic activity of the homogeneous NHC catalyst in a solution due to N
NHC-initiated cascade, metal-free synthesis of quinoxaline derivatives under solvent-free conditions
Gao, Lijiu,Liu, Rui,Yu, Chenxia,Yao, Changsheng,Li, Tuanjie,Xiao, Zhaoxin
, p. 2131 - 2138 (2014/05/06)
2,3-Diaryl quinoxaline derivatives have been efficiently synthesized by cascade, metal-free, and solvent-free reaction of aryl aldehydes with aryl 1,2-diamines initiated by N-heterocyclic carbene. Compared with reported methods, this procedure has the advantages of easy work-up, reduced energy consumption, and elimination of solvent waste, hazards, and toxicity. A group of potentially bioactive compounds has been prepared for biomedical screening.
The catalytic versatility of low toxicity dialkyltriazolium salts: In situ modification facilitates diametrically opposed catalysis modes in one pot
Myles, Lauren,Gathergood, Nicholas,Connon, Stephen J.
supporting information, p. 5316 - 5318 (2013/06/27)
The ability of triazolium salts to serve as a precatalyst for both an acid and a powerful base/nucleophile (controlled by additives) has been exploited in a process characterised by a unique in situ catalyst modification strategy. The Royal Society of Chemistry 2013.
