Acceleration of Cu(I)-mediated Huisgen 1,3-dipolar cycloaddition by histidine derivatives

Acceleration of Cu(I)-mediated Huisgen 1,3-dipolar cycloaddition (Sharpless 'click reaction') by non-basic histidine derivatives was found. An efficient 'self-activating' click reaction between the azide- and acetylene-containing peptides on the solid-phase has also been achieved by introducing the Nim-benzylhistidine residue on the reacting peptides.