ZnO nanoparticles: An efficient catalyst for transesterification reaction of α-keto carboxylic esters
作者:Mohamed M.A. Soliman、Anirban Karmakar、Elisabete C.B.A. Alegria、Ana P.C. Ribeir、Guilherme M.D.M. Rúbio、Marta S. Saraiva、M. Fátima C. Guedes da Silva、Armando J.L. Pombeiro
DOI:10.1016/j.cattod.2019.08.053
日期:2020.5
hexagonal wurtzite phase with high purity and SEM-EDS analysis confirm the purity and a homogenous distribution of the nanostructures. The ZnO nanostructures present plate-like agglomerates, resulting in a quasi-spherical morphology. The catalytic activity of the formed ZnO nanoparticles was evaluated towards the transesterification reaction of different carboxylic esters in the presence of various alcohols
Controllable chemoselectivity in the coupling of bromoalkynes with alcohols under visible-light irradiation without additives: synthesis of propargyl alcohols and α-ketoesters
作者:Ke Ni、Ling-Guo Meng、Hongjie Ruan、Lei Wang
DOI:10.1039/c9cc04090k
日期:——
The chemoselectivity of visible-light-induced coupling reactions of bromoalkynes with alcohols can be controlled by simple changes to the reaction atmosphere.
Chiral cobalt-catalyzed enantioselective aerobic oxidation of α-hydroxy esters
作者:Santosh Kumar Alamsetti、Govindasamy Sekar
DOI:10.1039/c0cc01917h
日期:——
A chiral cobalt-catalyzed enantioselective aerobic oxidative kinetic resolution of (±)-α-hydroxy esters, using molecular oxygen as a sole oxidant, is reported and a maximum of selectivity factor (s) 31.9 was achieved with >99% enantiomeric excess for unreacted α-hydroxy esters.
Oxime derivatives and the use thereof as photoinitiators
申请人:Ciba Specialty Chemicals Holding Inc.
公开号:EP1635220A2
公开(公告)日:2006-03-15
Radically photopolymerizable compositions comprising (a) at least one ethylenically unsaturated photopolymerizable compound; (b) as photoinitiator, at least one compound of the formula I, II, III and/or IV
wherein m is 0 or 1; n is 0, 1, 2 or 3; x is 1 or 2; R1 is inter alia phenyl, naphthyl, anthracyl or phenanthryl, a heteroaryl radical, C2-C12alkenyl, C4-C8cycloalkenyl, or C6-C12bicycloalkenyl; R'1 is inter alia C2-C12alkylene, or phenylene; R2 has one of the meanings of R1 or inter alia is phenyl; y is 1 or 2; R3 if x is 1 inter alia is C1-C18alkylsulfonyl, or phenyl-C1-C3alkylsulfonyl, R3 if x is 2, is for example C2-C12alkylenedisulfonyl; R4 and R5 inter alia are hydrogen, halogen, or C1-C8alkyl; A is for example -S-, -O-, or -NR10-; R10 inter alia is hydrogen, or phenyl; and (c) at least one coinitiator; are especially suitable for the preparation of colour filter systems.
A process for preparing an a-keto acid ester (oxo acid) of the formula:
wherein R1 is a hydrogen atom, aliphatic alkyl group of 1-6 carbon atoms, phenyl group or benzyl group, and R2 is an aliphatic alkyl group of 1-6 carbon atoms, which comprises causing an a-hydroxycarboxylic acid ester of the formula:
to react with molecular oxygen in a gaseous phase in the presence of copper phosphate, possibly, mounted on a solid carrier.