DBCO-C6-Acid, also known as ADIBO or DIBAC is a non-activated building block routinely used for synthesis of complex molecules to be used in Cu-free ligation applications. Primary or secondary amines can be efficiently functionalized with DBCO moiety in the presence of activators (e.g. EDC, or HATU) through a stable amide bond.
The extended 6-carbon long spacer arm improves solubility of this reagent in commonly used organic solvents such as dichloromethane, chloroform, THF, and ethyl acetate. In addition, extended spacer arm significantly improves coupling efficiency and stability of conjugates.