Tris-(benzyltriazolylmethyl)amine

tris-(benzyltriazolylmethyl)amine (TBTA) is a tertiary amine containing the 1,2,3-triazole moiety. When used as a ligand, complexed to copper(I), it allows for quantitative, regioselective Huisgen 1,3-dipolar cycloadditions between alkynes and azides, in a variety of aqueous and organic solvents.

It is believed that the ligand promotes catalysis through the stabilization of the copper(I)-oxidation state, while still allowing for the catalytic cycle of the CuAAC reaction to proceed. Tim's ligand is named after Tim Chan, who developed this molecule for use as a biological labelling tool while working as a graduate student for K. Barry Sharpless. In technical literature this catalyst is referred to as TBTA.