Cross-Claisen Condensation of<i>N</i>-Fmoc-Amino Acids - A Short Route to Heterocyclic γ-Amino Acids
作者:Loïc Mathieu、Clément Bonnel、Nicolas Masurier、Ludovic T. Maillard、Jean Martinez、Vincent Lisowski
DOI:10.1002/ejoc.201500012
日期:2015.4
cross-Claisen condensations between N-Fmoc-amino acids and sterically hindered 1,1-dimethylallyl acetate. The optimized conditions are compatible with aliphatic, aromatic, acidic, and basic amino acids. The resulting N-Fmoc-β-keto ester intermediates were engaged in a two-step process to give ATCs in 45–90 % yields. The synthetic protocol provides a highly flexible method for the introduction of a wide variety
4-氨基(甲基)-1,3-噻唑-5-羧酸(ATC)是一类新的受限杂环γ-氨基酸,围绕噻唑环构建;这些化合物作为蛋白质二级结构的设计模拟物是有价值的,例如螺旋、β-折叠、转角和 β-发夹。我们在此报告了一种用于正交保护的 ATC 的短而通用的化学途径。合成的中心是 N-Fmoc-氨基酸和空间位阻的 1,1-二甲基烯丙基乙酸酯之间的交叉克莱森缩合。优化的条件与脂肪族、芳香族、酸性和碱性氨基酸兼容。所得的 N-Fmoc-β-酮酯中间体通过两步法得到 ATC,产率为 45-90%。