For an improved method for O-tritylation in triethylamine in the presence of catalytic amounts of DMAP, see: Tetrahedron Lett., 95 (1979). For a one-pot procedure for the high yield, racemization-free N-tritylation of amino acids, by means of prior in situ O-silylation, see: J. Org. Chem., 47, 1324 (1982). N-Trt- derivatives of amino acids have also been converted to Leuchs' anhydrides by treatment with phosgene or triphosgene, and the products coupled with amino acid esters to give dipeptides in good yields without racemization: J. Org. Chem., 64, 2532 (1999).
