Spin trapping by tetraphenylcyclopentadienone and 2,3-diarylindenones. New long-lived radicals and their relevance to benzyne promotion from benzenediazonium acetate

Abstract

Benzenediazonium acetate, formed from N-nitrosoacetanilide in situ, in benzene in the presence of tetraphenylcyclopentadienone or 2,3-diarylindenones give e.s.r. signals corresponding to new long-lived radicals (2) and (3) formed by trapping of phenyl radicals by the dienones, thus providing evidence relating to the mechanism of benzyne promotion in these reactions.