120047-91-8Relevant articles and documents
Dinuclear manganese alkoxide complexes as catalysts for C-N bond cleavage of simple tertiary: N, N -dialkylamides to give esters
Nagae, Haruki,Hirai, Takahiro,Kato, Daiki,Soma, Shusei,Akebi, Shin-Ya,Mashima, Kazushi
, p. 2860 - 2868 (2019)
Amide bonds are stable due to the resonance between the nitrogen lone pair and the carbonyl moiety, and therefore the chemical transformation of amides, especially tertiary amides, involving C-N bond fission is considered one of the most difficult organic reactions, unavoidably requiring harsh reaction conditions and strong acids or bases. We report the catalytic C-N bond cleavage of simple tertiary N,N-dialkylamides to give corresponding esters using a catalyst system (2 mol% based on Mn atoms) of a tetranuclear manganese alkoxide, [Mn(acac)(OEt)(EtOH)]4 (1c), combined with four equivalents of 4,7-bis(dimethylamino)-1,10-phenanthroline (L1: Me2N-Phen). Regarding the reaction mechanism, we isolated a dinuclear manganese complex, [Mn(acac)(OEt)(Phen)]2 (6c), which was revealed as the catalytically active species for the esterification of tertiary amides.
Esterification of Tertiary Amides: Remarkable Additive Effects of Potassium Alkoxides for Generating Hetero Manganese–Potassium Dinuclear Active Species
Akiyama, Shoko,Himo, Fahmi,Hirai, Takahiro,Katayama, Shoichiro,Kato, Daiki,Mai, Binh Khanh,Mashima, Kazushi,Nagae, Haruki
supporting information, (2020/07/25)
A 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, we clarified a plausible reaction mechanism in which in situ generated manganese–potassium heterodinuclear species cooperatively activates the carbonyl moiety of the amide and the OH moiety of the alcohols. We also revealed details of the reaction mechanism of our previous manganese homodinuclear system 2 a, and we found that the activation free energy (ΔG≠) for the manganese–potassium heterodinuclear complex catalyzed esterification of amides is lower than that for the manganese homodinuclear system, which was consistent with the experimental results. We further applied our catalyst system to deprotect the acetyl moiety of primary and secondary amines.
Development of N-Doped Carbon-Supported Cobalt/Copper Bimetallic Nanoparticle Catalysts for Aerobic Oxidative Esterifications Based on Polymer Incarceration Methods
Yasukawa, Tomohiro,Yang, Xi,Kobayashi, Shu
supporting information, p. 5172 - 5176 (2018/09/12)
Heterogeneous nitrogen-doped carbon-incarcerated cobalt/copper bimetallic nanoparticle (NP) catalysts, prepared from nitrogen-containing polymers, were developed, and an efficient catalytic process for aerobic oxidative esterification was achieved in the presence of a low loading (1 mol %) of catalyst that could be reused and easily reactivated. This protocol enabled diverse conditions for the bimetallic NP formation step to be screened, and significant rate acceleration by inclusion of a copper dopant was discovered. The catalytic activity of the bimetallic Co/Cu catalysts is much higher than that for cobalt catalysts reported to date and is even comparable with noble-metal NP catalysts.
