Di-tert-butyl dicarbonate (Boc-anhydride, Boc2O)

Abstract

a) Boc-anhydride reacts smoothly with amino compounds in organic solvents or aqueous organic solvent mixtures, to obtain pure N-Boc-derivatives in high yields. b) Knolker et al. have disclosed a convenient route for the conversion of hindered alkyl and aryl amines into their corresponding isocyanates using Boc-anhydride in the presence of catalytic nucleophilic nitrogen base, especially DMAP. The strategy offers a safe alternative to hazardous phosgene conditions, which is the most widely utilized method for the synthesis of isocyanates. c) It is also used as a reagent for macrolactonisation of ω-hydroxy acids. The method involves activation of the carboxylic acid by Boc-anhydride, converting it into its mixed anhydride and intramolecular nucleophilic attack of hydroxy group on the activated carbon of the carboxy group forming the lactone. d) Recently our group has shown that dipeptides can be obtained under mild conditions using Boc2O as a peptide coupling reagent. The method also eliminates some commonly encountered problems during peptide coupling, such as, separation of product from reagent derived coproduct, racemisation, poor recovery of products, high cost and stability of the reagent etc.