Esterification of Tertiary Amides: Remarkable Additive Effects of Potassium Alkoxides for Generating Hetero Manganese–Potassium Dinuclear Active Species
作者:Takahiro Hirai、Daiki Kato、Binh Khanh Mai、Shoichiro Katayama、Shoko Akiyama、Haruki Nagae、Fahmi Himo、Kazushi Mashima
DOI:10.1002/chem.202001447
日期:2020.8.21
catalyst system of mononuclear manganese precursor 3 combined with potassium alkoxide served as a superior catalyst compared with our previously reported manganese homodinuclear catalyst 2 a for esterification of not only tertiary aryl amides, but also tertiary aliphatic amides. On the basis of stoichiometric reactions of 3 and potassium alkoxide salt, kinetic studies, and density functional theory (DFT) calculations
与我们之前报道的锰同双核催化剂2a相比,单核锰前体3与醇钾组合的催化剂体系不仅可以用于酯化叔芳基酰胺,还可以用于酯化叔脂肪族酰胺。在3和钾醇盐的化学计量反应、动力学研究和密度泛函理论(DFT)计算的基础上,我们阐明了一种合理的反应机制,其中原位生成的锰-钾异双核物种协同激活酰胺的羰基部分和醇的OH部分。我们还详细揭示了之前的锰同双核体系2 a的反应机理,我们发现锰钾异双核配合物催化酰胺酯化的活化自由能(Δ G ≠)低于锰同双核体系的活化自由能(Δ G ≠ ) ,与实验结果一致。我们进一步应用我们的催化剂系统对伯胺和仲胺的乙酰基部分进行脱保护。