Electron-transfer-induced reductive dealkoxylation of alkyl aryl ethers. III. Reductive cleavage of methoxy-substituted <i>N</i>,<i>N</i>-dimethylanilines (<i>N</i>,<i>N</i>-dimethylanisidines)

Abstract

The reactivity of the three isomeric methoxy-substituted N,N-dimethylanilines (N,N-dimethylanisidines) and of N,N-dimethyl-2,6-dimethoxyaniline in the reduction with alkali metals in aprotic solvents was investigated. N,N-Dimethyl-p-methoxyaniline was found to be unreactive, while the other substrates underwent exclusive cleavage of carbon-oxygen bond(s), with the following order of reactivity: 2,6-dimethoxy > o-methoxy > m-methoxy > p-methoxy. Both the relative reactivity and the regioselectivity of cleavage (demethoxylation vs. demethylation) was found to parallel closely that of the corresponding di- and trimethoxysubstituted substrates. These results suggest that intermediates with different electron distribution or even different intermediates are involved in the reductive cleavage of aryl-oxygen and arylnitrogen bonds