N,N-Diisopropylethylamine may be used in the synthesis of mannosylated ovalbumin peptides. Proton scavenger used in peptide coupling, enolboration, Pd(0)-catalyzed alkoxycarbonylation of allyl phosphates and acetates, and as a catalyst in vinyl sulfone synthesis.
It is commonly used as the hindered base in amide coupling reactions between a carboxylic acid (typically activated, for example, as an acid chloride, as illustrated below) and a nucleophilic amine. As DIPEA is hindered and poorly nucleophilic, it does not compete with the nucleophilic amine in the coupling reaction.
DIPEA is a good base used for deprotonation of carboxylic acid in peptides/amino acids to give you the intermediate carboxylate. It is added based on molar ratio.
Diisopropylamine is purified by heating to reflux over sodium hydroxide (NaOH) for 3–12 hr, followed by simple distillation from NaOH. 4. Butyllithium in hexanes (2.5 M) is purchased from Aldrich Chemical Company, Inc., and titrated using diphenylacetic acid.
