Synthesis and Electronic Properties of Sterically Demanding N-Arylphenothiazines and Unexpected Buchwald-Hartwig Aminations

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• 作者：Adam W. Franz ; Frank Rominger ; Thomas J. J. M&uuml ; ller
• 刊名：Journal of Organic Chemistry
• 出版年：2008
• 出版时间：March 7, 2008
• 年：2008
• 卷：73
• 期：5
• 页码：1795 - 1802
• 全文大小：269K
• 年卷期：v.73,no.5(March 7, 2008)
• ISSN：1520-6904

文摘

WFIGR ID=jo702389vn00001>Phenothiazine is coupled under Buchwald-Hartwig conditions with bromo anthracenes and perylene assubstrates to give phenothiazine-anthracene and phenothiazine-perylene dyads and triads. Investigationof the electronic properties of these sterically demanding N-aryl phenothiazines by absorption and emissionspectroscopy, cyclic voltammetry, and DFT calculations revealed that the individual chromophores aredecoupled in the electronic ground state but show unique electronic communication in the excited state.For the anthracenyl-bridged diphenothiazine an intense electronic coupling of the phenothiazinyl units isdetected upon oxidation. Besides, attempts to synthesize phenothiazine compounds with even moresterically demanding aryl substituents in the 10-position under N-arylation conditions gave rise to theformation of quite unexpected products of arylation and/or oxidative coupling. The folding angle of thephenothiazine in a consanguineous series correlates well with the first oxidation potential.