Peptide coupling reagents

is an organic compound with the chemical formula (C6H11N)2C. It is a waxy white solid with a sweet odor. Its primary use is to couple amino acids during artificial peptide synthesis. The low melting point of this material allows it to be melted for easy handling. It is highly soluble in dichloromethane, tetrahydrofuran, acetonitrile and dimethylformamide, but insoluble in water.

Hydroxybenzotriazole (abbreviated HOBt) is an organic compound with the formula . It is a derivative of benzotriazole. It is a white crystalline powder, which as a commercial product contains some water (~11.7% wt as the HOBt monohydrate crystal). Anhydrous HOBt is explosive. It is mainly used to suppress the racemization and to improve the efficiency of peptide synthesis.

planned process in synthetic organic chemistry

1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC, EDAC or EDCI) is a water-soluble carbodiimide usually handled as the hydrochloride, which is a white solid.

reagent commonly used in the synthesis of peptides

PyBOP (benzotriazol-1-yloxytripyrrolidinophosphonium hexafluorophosphate) is a reagent used to prepare amides from carboxylic acids and amines in the context of peptide synthesis. It can be prepared from 1-hydroxybenzotriazole and a chlorophosphonium reagent under basic conditions. It is a substitute for the BOP reagent that avoids the formation of the carcinogenic waste product HMPA. Thermal hazard analysis by differential scanning calorimetry (DSC) shows PyBOP is potentially explosive.

1-Hydroxy-7-azabenzotriazole (HOAt) is a triazole used as a peptide coupling reagent. It suppresses racemization that can otherwise occur during the reaction.

'''N,'-Diisopropylcarbodiimide is a carbodiimide used in peptide synthesis. As a liquid, it is easier to handle than the commonly used N,''-dicyclohexylcarbodiimide, a waxy solid. In addition, N,''-diisopropylurea, its byproduct in many chemical reactions, is soluble in most organic solvents, a property that facilitates work-up.

'''1,1'-Thiocarbonyldiimidazole (TCDI''') is a thiourea containing two imidazole rings. It is the sulfur analog of the peptide coupling reagent carbonyldiimidazole (CDI).

HATU (Hexafluorophosphate Azabenzotriazole Tetramethyl Uronium) is a reagent used in peptide coupling chemistry to generate an active ester from a carboxylic acid. HATU is used along with Hünig's base (N,N-diisopropylethylamine), or triethylamine to form amide bonds. Typically dimethylformamide is used as solvent, although other polar aprotic solvents can also be used.

HBTU (hexafluorophosphate benzotriazole tetramethyl uronium) is a coupling reagent used in solid phase peptide synthesis. It was introduced in 1978 and shows resistance against racemization. It is used because of its mild activating properties.