Mechanism of Azo Coupling Reactions: Part XXXVI. The Relationship between the Structure and the Catalytic Activity of Anionic Phase-Transfer Catalysts in Azo Coupling Reactions
dichloromethane/water system, and the effects of the solvent polarity and structure of counter anions on the reaction rates of the azo coupling of the diazonium ion 1 with N,N-dimethylaniline (4) and 1,3,5-trimethoxybenzene (2) in organic solvents and in dichloromethane/water system, were investigated. The symmetrical structure of the tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (TFPB) anion was proved
Phase-Transfer-Catalyzed Azo Coupling Reactions in Two-Phase Systems
作者:Yoji Hashida、Kazuhiro Kubota、Shizen Sekiguchi
DOI:10.1246/bcsj.61.905
日期:1988.3
The azo coupling reaction of p-methoxybenzenediazonium tetrafluoroborate with N,N-dimethylaniline has been investigated in a water-1,2-dichloroethane system. It has been found that, among the several additives examined, the phenolate ion, generated from picric acid or 2,4-dinitro-1-naphthol, acted as an effective phase-transfer catalyst. Further, the reaction of p-diethylaminobenzenediazonium tetrafluoroborate
Mechanisms of Diazo Coupling Reactions. Part XXXI. Aminoazo formation in the diazo coupling ofN, N-dimethylaniline andm-toluidine withp-methoxybenzenediazonium tetrafluoroborate in acetonitrile
作者:John R. Penton、Heinrich Zollinger
DOI:10.1002/hlca.19810640603
日期:1981.9.23
In the title reactions it is shown that aminoazo formation does not occur by direct attack of diazonium ion at C-atom. Initial attack is at N-atom, but proton loss from the ωN-complex formed is relatively slow. Hence, at low amine concentration this rearranges intermolecularly to the aminoazo derivative. At high amine concentration a second method of aminoazo formation can take place involving attack