Mechanistic insights into Brønsted acid-induced nucleophilic substitution of aliphatic imidazole carbamate with halide ions

Herein we report interesting reactivity of imidazole carbamate towards nucleophilic substitution with halide ions under Brønsted acidic conditions. Depending upon reaction conditions, halide ions could readily attack the carboxyl position and trigger decarboxylative alkyl halide formation. Alternatively, halide ions were also found to competitively undergo nucleophilic acyl substitution, which ultimately results in the generation of carbonate dimerization product.