Addition of carbanions to azobenzene in liquid ammonia

✍ Scribed by Edwin N. Kaiser; Gregory J. Bartling

• Book ID: 104240021
• Publisher: Elsevier Science
• Year: 1969
• Tongue: French
• Weight: 182 KB
• Volume: 10
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)88695-0

✦ Synopsis

Azobenzene (I) has long een own to react with carbanions to afford products wherein the azobenzene is reduced to aniline and/or hydrazobenzene with concomitant oxidative dimerization of the organometallic (1). For example, such reactions have been realized in ethyl ether with various metallophenyl reagents where the metal has been lithium, sodium, beryllium, magnesium, manganese, and zinc; biphenyl was often observed as the oxidation product (1). More recently, azobenzene has been reduced to its radical anion by a wide variety of alkali enolates, alkoxides, and carbanions derived from hydrocarbons in dimethyl sulfoxide solutions (2).

In contrast, addition of organometallic reagents across the azo linkage of azobenzene to afford substituted hydrazines has but rarely been observed. such additions to I appear to have been accomplished only with the highly reactive phenylcalcium iodide and phenylpotassium (l), and with phenyllithium (3) to afford triphenylhydrazine (II).