Chelating Picolinaldehyde Hydrazone Amides as Protecting Groups for Carboxylic Acids: Orthogonal Reactivities of Hydrazone Amides and Esters in Hydrolysis
Chelating Picolinaldehyde Hydrazone Amides as Protecting Groups for Carboxylic Acids: Orthogonal Reactivities of Hydrazone Amides and Esters in Hydrolysis
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DOI：
10.1021/acs.orglett.2c03670
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发表时间：
2022-12-13
期刊：
影响因子：
5.2
通讯作者：
Hara，Osamu
中科院分区：
文献类型：
--
作者：
Nishikawa，Yasuhiro;Mori，Daiki;Hara，Osamu
我们报道了一种作为羧酸保护基团的螯合肼。与大多数酯不同的是，2-吡啶甲醛肼在酸性或碱性条件下都是稳定的。然而，通过镍催化的水解法可以很容易地将肼基酰胺转化为相应的羧酸。通过对照实验和多肽合成，验证了酰氮酰胺与代表性保护基团的正交性，证明了螯合型保护基团是非常有用的保护基团。
We report a chelating hydrazone amide as a protecting group for carboxylic acids. Unlike most esters, 2-picolinaldehyde hydrazone amides are stable under acidic or basic hydrolytic conditions. However, hydrazone amides can be easily converted to the corresponding carboxylic acids via Ni-mediated hydrolysis. Orthogonal reactivities of the hydrazone amides and representative protecting groups were verified by control experiments and peptide synthesis, demonstrating that chelating hydrazone amides are highly useful protecting groups.