Auxiliary accelerated reactions: Towards the use of catalytic chiral auxiliaries
摘要:
In competition experiments, the acceleration of reactivity of alkenes tethered to pyridyl groups compared with the corresponding alkenes tethered to phenyl groups in the presence of transition metals was demonstrated for two reaction types: Diels-Alder cycloaddition of enoate esters and catalytic hydrogenation of allylic and homoallylic ethers. The rate accelerations observed are of crucial importance in the development of a new concept for asymmetric catalysis: chiral auxiliaries which can function in a catalytic manner. (C) 1997 Elsevier Science Ltd.
In competition experiments, alkenes tethered to pyridyl groups were found to undergo iridium catalysed hydrogenation more quickly than alkenes tethered to phenyl groups. This is in marked contrast to the results for hydrogenation of some of the individual substrates where alkenes tethered to pyridyl groups were reduced much more slowly than their phenyl counterparts.
Synthesis and initial thermal behavior investigation of 2-alkenyl substituted pyrazine N-oxides
作者:Ke Zhai、Miao Lai、Zhiyong Wu、Mingqin Zhao、Yanqiu Jing、Pengfei Liu
DOI:10.1016/j.catcom.2018.07.017
日期:2018.11
The systematic syntheses of 2-alkenylpyrazine N-oxides through palladium-catalyzed C-2 selective CH olefination reaction was disclosed. Various acrylateesters substituted pyrazine N-oxides were obtained in up to 93% yields. Thermogravimetric analysis indicated that the fracture temperature of particular compound 3 f was about 267 °C. The pyrolysis of compound 3 f could generate several aroma compounds
Curable liquids and inkjet inks for food packaging applications
申请人:Agfa Graphics N.V.
公开号:EP2604663A1
公开(公告)日:2013-06-19
A radiation curable liquid including at least one free radical polymerizable monomer or oligomer, at least one diffusion hindered acetalysation catalyst and at least one diffusion hindered hydroxyl containing compound. The radiation curable liquid applied to a substrate prevents migration of very low viscous monomers, such as vinyl ether acrylate monomers, into the substrate.