- 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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- Reaction on a solid surface - A simple, economical, and efficient Mannich reaction of azacrown ethers over graphite
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Graphite brings about a rapid Mannich reaction with a range of activated and unactivated phenolic compounds such as p-cresol and p-nitrophenol. The reactions are carried out with azacrown ether and paraformaldehyde in solvent-free conditions at 100 °C for 20-30 min. The graphite powder can be reused up to three times after simple washing with acetone.
- Sharghi, Hashem,Khalifeh, Reza
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p. 426 - 434
(2008/09/20)
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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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- Retro-Mannich reactions of 3-alkyl-3,4-dihydro-2H-1,3-benz[e]oxazines and the synthesis of axially chiral resorcinarenes
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Intermediates involved in the conversion of 3-alkyl-3,4-dihydro-2H-1,3-benz[e]oxazines into 2-N,N-dialkylaminomethylphenol derivatives, using morpholine and other high boiling secondary amines, have been identified and characterised. Additional experiments have established the involvement of o-quinone methide intermediates in the retro-Mannich reactions. Axially chiral resorcinarenes have been prepared by utilising the exchange reactions.
- Page, Philip C. Bulman,Heaney, Harry,McGrath, Matthew J.,Sampler, Edward P.,Wilkins, Robert F.
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p. 2965 - 2970
(2007/10/03)
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- 2-(2-Amino-2-methylpropyl)phenols by C-C-Linkage of 2-Hydroxybenzyl Alcohols with 2-Nitropropane Anions
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The 2-hydroxybenzyl alcohols 1, 6, 8a, and 8e can be converted into the 2-(2-methyl-2-nitropropyl)-phenols 2, 7, and 9 by a SRN1-reaction with the sodium salt of 2-nitropropane.Catalytic hydrogenation yields the amines 3 and 10.The consequent reactions - leading to the quaternary salts 13 and 14 and as to the addition-compounds 15 and 16 - are negatively influenced by the strong steric shielding of the amino groups.
- Diery, Helmut,Renger, Bernd
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p. 1239 - 1251
(2007/10/02)
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