Title: Cationic Arylation. V. Reaction of Substituted Benzenes with<i>p</i>-Nitrophenyl Cation
Abstract:The cationic arylation of substituted benzenes was investigated with p-nitrophenyl cation generated from p-nitrobenzenediazonium tetrafluoroborate in acetonitrile and from p-nitrophenylazo p′-tolyl su...The cationic arylation of substituted benzenes was investigated with p-nitrophenyl cation generated from p-nitrobenzenediazonium tetrafluoroborate in acetonitrile and from p-nitrophenylazo p′-tolyl sulfone in the presence of trifluoroacetic acid. The isomer distribution of substituted nitrobiphenyls produced and the partial rate factors indicated electrophilic character of the p-nitrophenyl cation. Selectivity of p-nitrophenyl cation is low compared with those of nitronium or sulfonyl cation, and similar to that of phenyl cation. These facts suggest that the p-nitrophenyl cation functions as a cation diradical with concerted uncoupling of a pair of π-electrons, one of which falls into the vacant sp2 σ-orbital.Read More