Synthesis of Constrained Head-to-Tail Cyclic Tetrapeptides by an Imine-Induced Ring-Closing/Contraction Strategy
作者:Clarence T. T. Wong、Hiu Yung Lam、Tao Song、Guanhua Chen、Xuechen Li
DOI:10.1002/anie.201304773
日期:2013.9.23
Making heads or tails of it: A strategy involving a head‐to‐tail imine‐captured ring closure followed by ring contraction was used to synthesize otherwise difficult cyclic tetrapeptides. Compared with the direct lactamization process, the estimated activation energies for the cyclic imine formation and the ring contraction were lowered by 7.3 and 7.6 kcal mol−1, respectively, which enables cyclization
制作正面或反面:采用由头至尾亚胺捕获的环闭合然后环收缩的策略来合成原本困难的环状四肽。与直接内酰胺化过程相比,估计的用于环状亚胺形成和环收缩的活化能分别降低了7.3和7.6 kcal mol -1,从而实现了环化作用。