An imidazolium-modified chiral rhodium/diamine-functionalized periodic mesoporous organosilica for asymmetric transfer hydrogenation of α-haloketones and benzils in aqueous medium
作者:Feng Zhou、Xiaoying Hu、Ming Gao、Tanyu Cheng、Guohua Liu
DOI:10.1039/c6gc01589a
日期:——
Use of a hydrophobic, imidazolium-functionalized periodicmesoporousorganosilica for immobilizations of chiral organometalliccomplexes as a heterogeneouscatalyst is a highly desirable as this catalyst can promote greatly an aqueous...
Truly Catalytic and Enantioselective Pinacol Coupling of Aryl Aldehydes Mediated by Chiral Ti(III) Complexes<sup>†</sup>
作者:A. Chatterjee、T. H. Bennur、N. N. Joshi
DOI:10.1021/jo0342875
日期:2003.7.1
A variety of chiral Ti(IV) complexes were reduced in situ with zinc in acetonitrile. The resulting chiral Ti(III) complexes were found to catalyze the pinacol coupling reaction stereoselectively. The best results were obtained from the Ti-SALEN complex, which was found to be an efficient catalyst at 10 mol % concentration. Various aromatic aldehydes were coupled to obtain chiral hydrobenzoin derivatives
Hydrogen Bonding-Assisted Enhancement of the Reaction Rate and Selectivity in the Kinetic Resolution of <i>d,l</i>
-1,2-Diols with Chiral Nucleophilic Catalysts
作者:Kazuki Fujii、Koichi Mitsudo、Hiroki Mandai、Seiji Suga
DOI:10.1002/adsc.201700057
日期:2017.8.17
An extremely efficient acylative kineticresolution of d,l‐1,2‐diols in the presence of only 0.5 mol% of binaphthyl‐based chiral N,N‐4‐dimethylaminopyridine was developed (selectivityfactor of up to 180). Several key experiments revealed that hydrogen bonding between the tert‐alcohol unit(s) of the catalyst and the 1,2‐diol unit of the substrate is critical for accelerating the rate of monoacylation
Biocatalyzed asymmetric reduction of benzils to either benzoins or hydrobenzoins: pH dependent switch
作者:Mohan Pal、Gautam Srivastava、Amar Nath Sharma、Suneet Kaur、Ravinder S. Jolly
DOI:10.1039/c5cy00158g
日期:——
synthesis. Biocatalytic reduction of benzils is a straightforward approach to prepare these molecules. However, known methods are not selective and lead to formation of a mixture of benzoin and hydrobenzoin, requiring expensive separation procedures. Here, we describe an enzyme system Talaromyces flavus, which exhibited excellent pH dependent selectivity for the conversion of benzil to either benzoin or
APPARATUS AND METHOD FOR CARRYING OUT MULTIPLE REACTIONS
申请人:Bowden Ned
公开号:US20090299102A1
公开(公告)日:2009-12-03
The invention provides methods and an apparatus useful for site-isolating reagents or catalysts during chemical reactions. The methods and apparatus are useful for carrying out cascade or domino reactions.