A convenient and efficient chemical toolbox was developed for the on-resin C-terminal functionalization of various peptides. By transforming resin-bound 3,4-diaminobenzoic acid species with isoamyl nitrite, the resulting resin-bound benzotriazole entity can be efficiently displaced by nucleophiles during cleavage of the peptide–resin connection in a short reaction time. The resin cleavage step allowed for the use of various nucleophiles including water, EtOH, amines, thiol, and G5 poly(amidoamino) dendrimers with yields ranging from 66% to 82% within 5 h. This method was successfully applied to prepare the elastin sequence (VPGVG)₄ through on-resin ligation in 77% yield in one day and a head-to-tail cyclic peptide, sunflower trypsin inhibitor-1, in 42% yield.

中文翻译：

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通过苯并三唑接头对肽C末端进行便捷的树脂上修饰†

开发了一种方便有效的化学工具箱，用于各种肽的树脂C端功能化。通过用亚硝酸异戊酯转化与树脂结合的3,4-二氨基苯甲酸物种，可以在短的反应时间内裂解肽-树脂连接的过程中，亲核试剂有效地置换所得的与树脂结合的苯并三唑实体。树脂裂解步骤允许使用各种亲核试剂，包括水，EtOH，胺，硫醇和G5聚（氨基氨基）树状聚合物，在5小时内的收率范围为66％至82％。该方法已成功应用于通过树脂上的连接在一天之内以77％的产率制备弹性蛋白序列（VPGVG）₄，并以42％的产率从头到尾的环状肽向日葵胰蛋白酶抑制剂1制备弹性蛋白序列（VPGVG）₄。