10282-36-7Relevant academic research and scientific papers
Cobalt-Catalyzed Regioselective para-Amination of Azobenzenes via Nucleophilic Aromatic Substitution of Hydrogen
Tao, Yigao,Hu, Rong,Xie, Zeyu,Lin, Ping,Su, Weiping
supporting information, p. 4724 - 4731 (2022/04/07)
The metal-catalyzed nucleophilic aromatic substitution of hydrogen (SNArH) via coordination of the substituent on the aromatic ring to the metal catalyst, in terms of reactivity, substrate type, and reaction selectivity, complements the transition metal-catalyzed C-H functionalization that proceeds via C-H metalation but remains an elusive target. Described herein is the development of an unprecedented cobalt-catalyzed para-selective amination of azobenzenes, which is essentially a metal-promoted SNArH process as revealed by Hammett analysis, thus illustrating the concept that coordination of the substituent on the arene ring to the metal catalyst may result in electrophilic activation of the arene ring toward SNArH. This cobalt-catalyzed protocol allows the use of a variety of both aliphatic amines and anilines as aminating reagents, tolerates electronically diverse substituents of azobenzene, and furnishes the corresponding products in good yields with a regiospecific selectivity for para-amination.
THE EFFECTS OF CYCLIC TERMINAL GROUPS IN 4-AMINOAZOBENZENE AND RELATED AZO DYES. PART 3. ELECTRONIC ABSORPTION SPECTRA OF SOME MONOAZO DYES DERIVED FROM N-PHENYLMORPHOLINE, N-(PHENYL)THIOMORPHOLINE, N-(PHENYL)THIOMORPHOLINE 1,2-DIOXIDE, AND N-ACETYL-N'-PHENYLPIPERAZINE
Hallas, Geoffrey,Marsden, Richard,Hepworth, John D.,Mason, Donald
, p. 123 - 126 (2007/10/02)
Monoazo dyes containing a terminal morpholino group absorp hypsochromically in comparison with their piperidino counterparts as a result of electron withdrawal by the oxygen atom.Similar shifts are observed with related dyes possessing other γ-heteroatoms in the donor group.In acid solution, protonation takes place at the β-azo nitrogen atom (azonium tautomer) and at the terminal nitrogen atom (ammonium tautomer) to an extent which depends on the inductive effect of the γ-substituent.
