Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... Aryl esters of Boc- and Fmoc-protected amino acids derived from electron-deficient phenols have been prepared in good yields from aryl 4-nitrobenzenesulfonates in the presence of 1-hydroxy-benzotriazole as catalyst. ... Aryl esters of protected amino acids were ...