ELECTRON WITHDRAWING GROUP-CONTAINING METAL COMPOUNDAn electron-withdrawing group-containing metal compound (I) represented by 'the general formula [9]:[9] [(R[err][err]X[err] ) k[err]M[err]O]mT[err]R[err][err]wherein M[err] represents a zinc atom; X[err] represents an atom of ...
Indoles having substituents at both the 2- and 3-positions may yield products derived from the initial formation of 2,3,3-trisubstituted 3H-indoles, but when the system is substituted at the 1-, 2- or 3-position by electron-withdrawing groups, thereby rendering the five-membered ring less ...
This confirms the experimental observation that negative charges are mainly localized on the coordinated phenyl ring, while the uncoordinated phenyl ring acts only as an electron withdrawing group. Impor- tantly, the putative complex 5-Y2 À , in which each yttrium ion is coordinated to a ...
indicate, however, that there is no straightforward relationship between the electron-donating or electron-withdrawing nature of the α-substituent and scissioning efficiency.101A brief compilation of some representative examples of these substituted acrylate polymers and copolymers is shown inTable 1. ...
Table 1 Effects of reaction conditions on the yield and the conversion rate 溶剂 转化率/ % 产率/ % 乙腈98 24 丙酮99 17 氯仿50 1 二氯甲烷 99 2 正己烷 87 1 首先我们以对溴苯甲酸甲酯和苯的光化反应为 模板反应,通过对反应的溶剂和反应时间的摸索来确 定最优的反应条件(表1). 当我们使用对溴苯...
Full size table Reaction scope With optimal reaction conditions at hand, we then examined the scope of this radical coupling reaction with aryl allenyl ethers 1 bearing different substituents (Fig. 2a). Both electron-donating and electron-withdrawing groups can be introduced to the benzene ring of...
This confirms the experimental observation that negative charges are mainly localized on the coordinated phenyl ring, while the uncoordinated phenyl ring acts only as an electron withdrawing group. Impor- tantly, the putative complex 5-Y2 À , in which each yttrium ion is coordinated to a ...
A monomer containing an electron-withdrawing group and an electron-donative group which can be easily controlled in the upper limit of the amount of a sulfonic acid, which impairs the mechanical prope
P-phenylenediamines having a quaternary ammonium group and substituted with an electron withdrawing group, derivatives thereof, compositions containing same, and their use as developers for dyeing keratinous fibers, are disclosed. Application Number: 07/798452 Publication...
The piperazine radical cation is not formed in the fragmentation of protonated N-(4-methylbenzyl)piperazine (Compound 3) and N-benzylpiperazine (Compound 4), whereas this radical cation can be distinctly observed when a strong electron-withdrawing group, such as NO2 and CF3, connects to the ...