- Manganese-Catalyzed Aminomethylation of Aromatic Compounds with Methanol as a Sustainable C1 Building Block
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This study represents the first example of a manganese-catalyzed environmentally benign, practical three-component aminomethylation of activated aromatic compounds including naphtols, phenols, pyridines, indoles, carbazoles, and thiophenes in combination with amines and MeOH as a C1 source. These reactions proceed with high atom efficiency via a sequence of dehydrogenation and condensation steps which give rise to selective C-C and C-N bond formations, thereby releasing hydrogen and water. A well-defined hydride Mn(I) PNP pincer complex, recently developed in our laboratory, catalyzes this process in a very efficient way, and a total of 28 different aminomethylated products were synthesized and isolated yields of up to 91%. In a preliminary study, a related Fe(II) PNP pincer complex was shown to catalyze the methylation of 2-naphtol rather than its aminomethylation displaying again the divergent behavior of isoelectronic Mn(I) and Fe(II) PNP pincer systems.
- Mastalir, Matthias,Pittenauer, Ernst,Allmaier, Günter,Kirchner, Karl
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supporting information
p. 8812 - 8815
(2017/07/12)
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- Ruthenium-Catalyzed Aminomethylation and Methylation of Phenol Derivatives Utilizing Methanol as the C1 Source
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A reaction involving ortho-aminomethylation of phenol was developed via ruthenium-catalyzed dehydrogenation of methanol, an environmentally benign C1 building block, without the use of reactive reagents. The reaction was successfully applied to a range of substrates. When naphthol was employed instead of phenol, only methylation was observed. On the basis of various mechanistic studies, we propose that formamide barely participates in the reaction, which mainly occurs through an iminium cation intermediate. The difference in the reactivities of phenol and naphthol is attributable to stronger basicity of naphtholate as a conjugate base owing to its lower aromaticity. Plausible reaction pathways were proposed for both reactions. (Figure presented.).
- Kim, Seoksun,Hong, Soon Hyeok
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p. 798 - 810
(2017/03/11)
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- Proton-electron transfer pathways in the reactions of peroxyl and dpph ? radicals with hydrogen-bonded phenols
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The kinetics of the reaction of peroxyl and dpph? radicals with phenols H-bonded to N-bases have been studied for the first time. Electron-transfer processes are observed in MeCN but only with the dpph radical.
- Amorati, Riccardo,Menichetti, Stefano,Viglianisi, Caterina,Foti, Mario C.
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supporting information
p. 11904 - 11906
(2013/01/16)
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- Regioselective mannich reaction of phenols under high pressure using dichloromethane as C1 unit
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Regioselectivity in Mannich reaction of 4-, 3-, and 2-substituted phenols with typical heterocyclic amines are investigated under reaction conditions developed by us. Phenol and 4-alkyl, and 4-chlorophenols in the title reaction predominantly gave the corresponding 2-(aminomethyl)phenols, while 4-methoxyphenol afforded, in addition to the mono(aminomethyl)phenols, a considerable amount of the bis adducts. Peculiarly enough, 3-methylphenol with amines afforded 3-methyl-4-(aminomethyl)phenols whereas 2-methylphenol produced 2-methyl-6-(aminomethyl)phenols.
- Matsumoto, Kiyoshi,Joho, Kouta,Mimori, Seisuke,Iida, Hirokazu,Hamana, Hiroshi,Kakehi, Akikazu
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scheme or table
p. 1061 - 1067
(2009/06/28)
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