Evaluation of Electrophilic Activities of Substituted Nitroarenes in the VNS Reaction with Secondary and Tertiary Carbanions

Relative electrophilic activities of substituted nitroarenes in the vicarious nucleophilic substitution (VNS) reaction with carbanion of chloromethyl p-chlorophenyl and bromo - methyl phenyl sulfones, 1 and 2, were determined via competitive experiments. The results are in good agreement with relative activities determined earlier in the competitive experiments with carbanion of chloromethyl phenyl sulfone 3 confirming reliability of these data. On the other hand, analogous competitive experiments with tertiary carbanions of chloroform and 1-chloroethyl phenyl sulfone gave results much affected by steric effects thus the VNS reaction with these carbanions can not be used for evaluation of electrophilic activities of nitroarenes.