Minisci

Minisci reactions have also been applied to these compounds. formation by exposure to w-CPBA and O-methylation with Meerwein s reagent converted 54 into 55. Nucleophilic attack of the hydroxymethyl radical, generated with ammonium sulfate, provides an alternate route to 2-hydroxymethyl pyridines 56. 

More recently Minisci et al. (1986) compared the rate constants for phenylation of 4-cyanopyridine in the 2- and 3-positions by benzenediazonium ions, catalyzed by Cu+ and by Fe2+, with the rates of the same phenylations using benzoyl peroxide under similar conditions. The rate constants found for the phenylation steps were, within experimental error, the same. 

A completely different method of synthesis of azo compounds from diazonium salts involving radical intermediates was found by Citterio et al. (1980, 1982 c), Cit-terio and Minisci (1982), and Fontana et al. (1988). It is a new general synthesis of arylazoalkanes based on the addition of an alkyl radical to an arenediazonium ion followed by reduction of the intermediate azo radical cation adduct by a metal salt (Scheme 12-80). The preferred source for the alkyl radical R in this reaction is an alkyl iodide, which gives rise to alkyl radicals cleanly in the presence of an arenediazonium salt and a Ti3+ or Fe2+ salt as in Scheme 12-81. The overall stoichiometric equation is therefore as given in Scheme 12-82. The yields vary between 36% and 79% (with respect to alkyl iodide). 

The reaction has been extended to the formation of primary aromatic amines, but the scope is narrow Citterio, A. Gentile, A. Minisci, F. Navarrini, V. Serravalle, M. Ventura, S. J. Org. Chem., 1984, 49, 4479. 

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