Title | Probing Delocalization Across Alkyne-Containing Linkages: Synthesis and Cyclic Voltammetry of Bridged Phenylenediamines. |
Publication Type | Journal Article |
Year of Publication | 1995 |
Authors | Zhou, Q, Swager, TM |
Journal | Journal of Organic Chemistry |
Volume | 60 |
Pagination | 7096–7100 |
ISSN | 0022-3263 |
Keywords | bridged phenylenediamine prepn cyclic voltammetry |
Abstract | This paper presents the synthesis of N,N,N',N'-tetraethyl-1,4-phenylenediamines bridged by ethynyl-phenyl-ethynyl and diethynyl linkages. These compds. are of interest to det. if the N,N,N',N'-tetraethyl-1,4-phenylenediamines exhibit delocalized mixed oxidn. states when oxidized electrochem. 1-Butoxy-2,5-bis(N,N-diethylamino)-4-ethynylbenzene was a key intermediate, and nucleophilic addn. of lithium (trimethylsilyl)acetylide to 2,5-bis(N,N-diethylamino)-1,4-benzoquinone provided an efficient synthesis of this compd. This intermediate was then assembled into the redox assemblies of interest in high yield by use of palladium-catalyzed cross-coupling and copper-catalyzed oxidative homo-coupling protocols. Cyclic voltammetry of these compds. indicate that the N,N,N',N'-tetraethyl-1,4-phenylenediamine redox units behave independently and that the only interactions are electrostatic. As a result, we conclude that the electrochem. generated radical cations and dications are highly localized. [on SciFinder(R)] |
DOI | 10.1021/jo00127a011 |