NNdiisopropylethylamine

NN-Diisopropylethylamine, often abbreviated as DIPEA or Hünig's base, is a colorless liquid with a characteristic amine odor. It is a sterically hindered, non-nucleophilic base commonly used in organic synthesis. Its chemical formula is C8H19N. The presence of two isopropyl groups attached to the nitrogen atom prevents it from acting as a nucleophile, meaning it is unlikely to participate in reactions by attacking electrophilic centers. This property makes it particularly useful in reactions where a strong base is required, but nucleophilic attack by the base itself would lead to unwanted side products.

DIPEA is frequently employed in peptide synthesis to deprotonate amino acids or to neutralize acids generated during coupling reactions. It is also used in alkylation reactions, protection group chemistry, and in various coupling reactions such as the Mitsunobu reaction. Its relatively high boiling point (approximately 127 °C) makes it easy to remove from reaction mixtures by distillation. DIPEA is soluble in most common organic solvents, including diethyl ether, tetrahydrofuran, and dichloromethane. While it is a strong base, it is generally considered less reactive than some other common organic bases like triethylamine, offering a useful balance of reactivity and selectivity. It is important to handle DIPEA with appropriate safety precautions, as it is an irritant and should be used in a well-ventilated area.