Zinc-Catalyzed Esterification of <i>N</i>
-β-Hydroxyethylamides: Removal of Directing Groups under Mild Conditions
作者:Yuji Nishii、Takahiro Hirai、Sarah Fernandez、Paul Knochel、Kazushi Mashima
DOI:10.1002/ejoc.201700748
日期:2017.9.15
Amide transformations involving C-N bond cleavage are recognized as difficult reactions owing to the inert nature of amides resulting from resonance. Accordingly, a strong inductive effect and geometrical distortion reasonably decrease the resonance stabilization to attenuate the C-N linkage. Although the conversion of such activated amides has been studied intensively, reaction systems for unactivated
由于由共振引起的酰胺的惰性性质,涉及 CN 键断裂的酰胺转化被认为是困难的反应。因此,强感应效应和几何失真合理地降低了共振稳定性以衰减 CN 链接。尽管已经对此类活化酰胺的转化进行了深入研究,但未活化酰胺的反应体系尚未开发。我们在此报告了三氟甲磺酸锌 (II) [Zn(OTf)(2)] 催化剂在分子内酰基重排的帮助下实现了多种未活化的叔酰胺的酯化。该反应用于在温和的反应条件下一锅脱除各种酰胺基导向基团,以高产率得到相应的酯。