Zinc chloride homogeneous catalysis in the tritylation of hydroxyl- and amide-bearing molecules

A simple and mild tritylation method based on Tr+ transfer from trityl esters to substrates having hydroxyl- or carboxamide- groups is presented. The protocol requires only catalytic amounts of ZnCl2. The results are compared with those obtained with the procedure based on the use of equimolar mixtures of TrCl and ZnCl2 in the presence of TEA.