Carbamate formation
Abstract
Carbamates are functional groups containing both an ester-like and an amide-like bond linked through a single carbonyl. They are among the most important protecting groups for amines in synthesis, extensively used in solid phase peptide synthesis.
Keywords
Amine, Chloroformate, Carbamate
Category
Amine
Mechanism
Mechanistically, the amine acts as a nucleophile and attacks the electrophilic carbonyl carbon of the chloroformate, yielding a tetrahedral intermediate in which the nitrogen bears a positive charge. Then, the intermediate collapses with expulsion of a chloride ion and deprotonation of the nitrogen by the base (typically, triethylamine or diisopropylethylamine), directly yielding the carbamate. The HCl generated is neutralized by the base.
