There is a continuing need for the development of new protecting groups for amines which can be cleaved under conditions that are mild and fundamentally different from what are already available. In this paper, we report our studies in using o-hydroxy-trans-cinnamic acid as a photo-sensitive protecting group for amines. The design takes advantage of the trans-cis photo-isomerization and the ensuing facile lactonization of o-hydroxy-cis-cinnamic acid and derivatives. We have found that both the protection and deprotection can be carried out in high yields for a variety of amines with different structural features. The deprotection reaction uses low intensity UV light (365 nm), which is fundamentally different from the conditions used for the deprotection of other commonly used amino-protecting groups. Therefore, the method complements other available methods in allowing for selective manipulation of different functional groups in a complex organic molecule.
我们一直需要开发新的胺保护基团,这种保护基团可以在温和的条件下裂解,而且与现有的保护基团有本质区别。在本文中,我们报告了使用邻羟基反式
肉桂酸作为胺的光敏保护基团的研究。该设计利用了邻羟基-顺式
肉桂酸及其衍
生物的反式-顺式光异构化和随之而来的简易内酯化。我们发现,对于具有不同结构特征的各种胺,保护和脱保护反应都能以高产率进行。脱保护反应使用低强度紫外光(365 纳米),这与其他常用
氨基保护基团的脱保护条件有本质区别。因此,该方法是对其他现有方法的补充,可以对复杂有机分子中的不同官能团进行选择性操作。