The electrochemical preparation and kinetic and product studies of acylated quinol and quinol ether imines. In search of the hydrolysis products of the ultimate carcinogen of N-acetyl-2-aminofluorene
摘要:
The N-acetyl and benzoyl derivatives of 4-methoxy-4-phenyl-2,5-cyclohexadienone imine and the N-benzoyl derivative of 4-hydroxy-4-phenyl-2,5-cyclohexadienone imine (1a-c) have been prepared via anodic oxidation of the corresponding amide of 4-aminobiphenyl in either methanol or water/acetonitrile, respectively. The products and the kinetics of the acidic and basic hydrolyses of these compounds were studied and the results compared with other N-acylquinol imine derivatives, including N-acetyl-4-hydroxy-4-phenyl-2,5-cyclohexadienone imine (1d), generated by solvolytic routes. The chemistry of these compounds was dependent upon the pH and the substituents on the quinol imine derivative. The major reaction pathways were hydrolysis of the imine linkage to afford the respective dienone and phenyl migration to afford the amides of 2-hydroxy- or 2-methoxy-5-aminobiphenyl. The reactivity of the quinol imine derivatives follows the order: 4-hydroxyl more reactive than 4-methoxyl compounds and N-acetyl more reactive than N-benzoyl derivatives. The higher reactivity for the former compounds is attributed to the greater electron-donating ability of the 4-hydroxyl versus the 4-methoxyl group. The higher reactivity of the N-acetyl relative to the N-benzoyl derivatives is attributed to the ca. 30-fold increase in basicity of the N-acetyl functionality. The additive effect of the 4-hydroxyl and N-acetyl functionality on the basic quinol imine moiety makes compounds having both of the groups difficult to isolate in aqueous media. This serves as a limitation for the preparation of the quinol imine derivative of N-acetyl-2-aminofluorene via the anodic oxidation methods reported herein.
The electrochemical preparation and kinetic and product studies of acylated quinol and quinol ether imines. In search of the hydrolysis products of the ultimate carcinogen of N-acetyl-2-aminofluorene
摘要:
The N-acetyl and benzoyl derivatives of 4-methoxy-4-phenyl-2,5-cyclohexadienone imine and the N-benzoyl derivative of 4-hydroxy-4-phenyl-2,5-cyclohexadienone imine (1a-c) have been prepared via anodic oxidation of the corresponding amide of 4-aminobiphenyl in either methanol or water/acetonitrile, respectively. The products and the kinetics of the acidic and basic hydrolyses of these compounds were studied and the results compared with other N-acylquinol imine derivatives, including N-acetyl-4-hydroxy-4-phenyl-2,5-cyclohexadienone imine (1d), generated by solvolytic routes. The chemistry of these compounds was dependent upon the pH and the substituents on the quinol imine derivative. The major reaction pathways were hydrolysis of the imine linkage to afford the respective dienone and phenyl migration to afford the amides of 2-hydroxy- or 2-methoxy-5-aminobiphenyl. The reactivity of the quinol imine derivatives follows the order: 4-hydroxyl more reactive than 4-methoxyl compounds and N-acetyl more reactive than N-benzoyl derivatives. The higher reactivity for the former compounds is attributed to the greater electron-donating ability of the 4-hydroxyl versus the 4-methoxyl group. The higher reactivity of the N-acetyl relative to the N-benzoyl derivatives is attributed to the ca. 30-fold increase in basicity of the N-acetyl functionality. The additive effect of the 4-hydroxyl and N-acetyl functionality on the basic quinol imine moiety makes compounds having both of the groups difficult to isolate in aqueous media. This serves as a limitation for the preparation of the quinol imine derivative of N-acetyl-2-aminofluorene via the anodic oxidation methods reported herein.
The chemistry of pentavalent organobismuth reagents
作者:Derek H.R. Barton、Neerja Yadav-Bhatnagar、Jean-Pierre Finet、Jamal Khamsi、William B. Motherwell、Stephen P. Stanforth
DOI:10.1016/s0040-4020(01)89960-9
日期:1987.1
the substituents on the phenol on the regiochemtstry of the arylation reactions with Ph3BiCl2 and other bismuth reagents has been studied. -Phenylation occurs with phenols substituted with electron-withdrawing groups. Electron-donating substituted phenols undergo -phenylation. Oxidative dimerisation has been observed with 2,6-dialkyl phenols.
Pd(II)-Catalyzed C−H Activation/Aryl−Aryl Coupling of Phenol Esters
作者:Bin Xiao、Yao Fu、Jun Xu、Tian-Jun Gong、Jian-Jun Dai、Jun Yi、Lei Liu
DOI:10.1021/ja909818n
日期:2010.1.20
reactions have been well-known, Pd(II) insertion into C-H bonds promoted by coordination of an oxygen-only group to the palladium remains rather rare. In the present study, the first cyclopalladation complex formed from a simple phenol ester was characterized by X-ray crystallography. A promising protocol for the ortho C-H activation/aryl-aryl coupling of phenol esters that was not sensitive to moisture
尽管含氮基团导向的环钯化反应已广为人知,但通过仅含氧的基团与钯的配位促进 Pd(II) 插入 CH 键的情况仍然相当罕见。在本研究中,第一个由简单苯酚酯形成的环钯化配合物通过 X 射线晶体学表征。然后建立了对水分或空气不敏感的苯酚酯邻位 CH 活化/芳基-芳基偶联的有前途的方案。该反应的效用已被证明可用于合成有用的苯酚衍生物。
Service users' knowledges and social work theory: conflict or collaboration?
作者:P. Beresford
DOI:10.1093/bjsw/30.4.489
日期:2000.8.1
So far, service users have not been systematically involved in social work theorizing. However, disabled peoples's movements, mental health service users/survivors and other service users have developed their own knowledges based on direct experience and they have generated their own conceptual frameworks and bodies of theory. There are fundamental problems in social work seeking to interpret service user knowledges. Their developments and interpretation require the direct involvement of service users and their organization in social work theorizing. There are strong practical, philosophical and political arguments for involving the knowledges and theories of service users and their organizations in the process of social work theory-building. This paper considers an inclusive approach to social work theorizing. While highlighting the importance of service users and their organizations being effectively included in social work theorizing, it also argues the need for them to have support and opportunities to develop their own prior and separate discussions about theory, including social work theory.