Halogenated aryldiazonium salts

Halogenated Cinnamic Acids and Esters Thereof, Processes for the Preparation Thereof and Halogenated Aryldiazonium Salts M. Beller etal, US Patent 5,516,932 (May 14, 1996)... 

There are reasons to explain the catalytic activity of copper(ll) in terms of cation-radical mechanism. This mechanism is confirmed by the unusual direction of Meerwein reaction in some cases, for example, when the replacement of halogen by an aryl radical occurs in the reaction of halo-styrenes with aryldiazonium salts (Obushak et al. 1991). A cation-radical in the system [olefin-Cu(II)] has been detected by UV spectroscopy (Obushak et al. 1991). In the cases of cis isomers of benzylidenacetone (Allard and Levisalles 1972) and maleic esters (Isaev et al. 1972), the unreacted... 

In the reactions between the halogenated dialkyl (2-oxoethyl)phosphonates (216 X = halogen) and aryldiazonium salts in aqueous sodium acetate, loss of the CHO group occurs when X = Cl... 

The only diazocyclopentadiene hitherto reported whose reactions resemble those of an aryldiazonium salt is the tetracyano-derivative, whose diazo-grovp can be replaced by hydrogen, halogens, cyano, etc. under the appropriate conditions [41,117]. 

Benzotropolones take part in electrophilic substitution reactions, for example halogenation [293,328,331] and coupling with aryldiazonium salts [332]. They may undergo rearrangement to benzenoid compounds in some instances, for example treatment of 3,4-benzotropolone with excess bromine gives 2,3-dibromonaphtho-quinone and with excess concentrated nitric acid leads to 2,4-di-nitro-l-naphthol [333]. Like other tropolones, 3,4-benzotropolone is photochemically converted into a bicycloheptadienone [334]... 

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