Enamines reactions with diazonium salts

Reactions of enamines with diazonium salts have also been reported. Treatment of benzenediazonium chloride with l,3,3-trimethyl-2-methyleneindoline gave an azo compound,283 whereas with aliphatic enamines the final products were hydrazines of a-ketoaldehydes 284 or a-diketones (Scheme 10). 

Some of the examples where a diazo or a diazonium compound reacts with activated double bonds, specifically with enamines and with 1,2-dimethoxy-ethene have been mentioned in sections 2.1.2 and 2.1.4, respectively (12, 29). A similar reaction is the azo coupling of arenediazonium salts with tropolones (34) The diazonio group reacts at the C-5 atom, so the reaction is used as a diagnostic tool for the presence of substituents at C-5, as well as for the synthesis of 5-amino tropolones by reduction of the azo compound. 

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