Esterification of Tertiary Amides: Remarkable Additive Effects of Potassium Alkoxides for Generating Hetero Manganese–Potassium Dinuclear Active Species
catalyst system of mononuclear manganese precursor 3 combined with potassiumalkoxide 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 potassiumalkoxide 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。
Ru-catalyzed 1,4-addition of arylboronic acids to acrylic acid derivatives in the presence of phenols
[Ru(p-cymene)Cl2]2-catalyzed 1,4-addition reactions between arylboronic acids and butyl acrylate and acrylamide in the presence of phenols were investigated, good to excellent yields were obtained. The addition of phenols remarkably promoted the protonolysis and inhibited the β-H elimination of the 1,4-addition intermediates, and also efficiently suppressed the protonolysis of arylboronic acids.
Air-tolerant, ligand-free nickel-catalyzed, manganese-assisted reductive Heck reaction of alkyl/aryl halides with electron-deficient olefins
作者:Minling Xü、Lijia Qian、Gang Zou
DOI:10.1016/j.mcat.2023.113291
日期:2023.8
An air-tolerant reductiveHeckreaction of alkyl/arylhalides with α, β-unsaturated esters, nitriles and amides catalyzed by simple nickel bromide has been developed by using manganese as reductant in refluxing acetonitrile. Water plays a double-face role in the catalytic process, hydrolysis of the enolate and/or C-tautomer intermediates to afford the conjugate adducts while suppressing the catalysis
Nickel(I) complexes were generated in situ from Ni (PPh3)2Cl2 using activated iron and the complexes combined with N,N′-bis(4-fluorobenzylidene) ethane-1,2-diamine (BFBED) were then used as a catalyst for the 1,4-addition reaction of arylboronic acids to α,β-unsaturated substrates. The reaction proceeded to completion and did not require the addition of a base but the addition of potassium iodide is