- Transition metal-free methylation of amines with formaldehyde as the reductant and methyl source
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A simple transition metal-free procedure using formaldehyde for the N,N-dimethylation and N-methylation of primary and secondary anilines is reported. The reaction showed limitations on sterically hindered and electron-withdrawing anilines, but is successful on amines with electron-donating substituents. Formaldehyde acts as both the reducing agent and the carbon source in the reaction.
- Man, Nikki Y.T.,Li, Wanfang,Stewart, Scott G.,Wu, Xiao-Feng
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p. 345 - 347
(2015/11/25)
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- A novel squaraine dye with squaramide as a scaffold and the colorimetric detection of amine
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A novel unsymmetrical squaramide-linked squaraine dye (SQ) has been synthesized through squaramide 3 and semisquaraine 6. The molecular structure of SQ has been characterized by 1H NMR, IR and MS. Due to the influence of the hydrogen bond and the solvent effect, SQ exhibits unique spectral properties compared with typical squaraine dyes. For its excellent ability of binding primary amine, SQ is a promising receptor of recognizing primary amine.
- Sun, Chuan Guo,Lin, Qian,Fu, Nan Yan
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scheme or table
p. 217 - 220
(2012/06/29)
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- Ruthenium-catalyzed oxidative cyanation of tertiary amines with molecular oxygen or hydrogen peroxide and sodium cyanide: Sp3 C-H bond activation and carbon-carbon bond formation
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Ruthenium-catalyzed oxidative cyanation of tertiary amines with molecular oxygen in the presence of sodium cyanide and acetic acid gives the corresponding α-aminonitriles, which are highly useful intermediates for organic synthesis. The reaction is the first demonstration of direct sp3 C-H bond activation α to nitrogen followed by carbon-carbon bond formation under aerobic oxidation conditions. The catalytic oxidation seems to proceed by (i) α-C-H activation of tertiary amines by the ruthenium catalyst to give an iminium ion/ruthenium hydride intermediate, (ii) reaction with molecular oxygen to give an iminium ion/ruthenium hydroperoxide, (iii) reaction with HCN to give the α-aminonitrile product, H2O2, and Ru species, (iv) generation of oxoruthenium species from the reaction of Ru species with H2O2, and (v) reaction of oxoruthenium species with tertiary amines to give α-aminonitriles. On the basis of the last two pathways, a new type of ruthenium-catalyzed oxidative cyanation of tertiary amines with H2O2 to give α-aminonitriles was established. The α-aminonitriles thus obtained can be readily converted to α-amino acids, diamines, and various nitrogen-containing heterocyclic compounds.
- Murahashi, Shun-Ichi,Nakae, Takahiro,Terai, Hiroyuki,Komiya, Naruyoshi
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supporting information; experimental part
p. 11005 - 11012
(2009/02/05)
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- Aerobic Ruthenium-Catalyzed Oxidative Cyanation of Tertiary Amines with Sodium Cyanide
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RuCl3-catalyzed oxidative cyanation of tertiary amines with sodium cyanide under molecular oxygen (1 atm) at 60 °C gives the corresponding α-aminonitriles, which are versatile synthetic intermediates of various compounds such as amino acids and
- Murahashi, Shun-Ichi,Komiya, Naruyoshi,Terai, Hiroyuki,Nakae, Takahiro
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p. 15312 - 15313
(2007/10/03)
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- Conformation-Dependent Intramolecular Electron Transfer in N-(Aminoalkyl)-9-phenanthrenecarboxamides
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The molecular structure and photophysical behavior of several secondary and tertiary N-(aminoalkyl)phenanthrenecarboxamides have been investigated.Secondary (aminoalkyl)amides exist predominantly in the Z conformation, whereas tertiary amides exist as mixtures of Z and E conformers and semirigid piperazines as mixtures of chair conformers.Rate constants for endergonic intramolecular electron transfer are found to be highly dependent upon molecular structure.The aromatic and amide groups of the tertiary amides are essentially orthogonal, and thus, an E aminoalkyl group can adopt low-energy conformations in which there is spatial overlap between the aromatic and amine groups, whereas such overlap is not possible for either a Z aminoalkyl group or the piperazines.The observation of more rapid intramolecular electron transfer quenching of the phenanthrene singlet by an appended trialkylamine in the E vs Z conformation is attributed to this difference in overlap.An increase in the phenanthrene-amide dihedral angle is also found to result in a decrease in the rate constant for intramolecular electron transfer quenching by a Z aminoalkyl group.In the case of appended tertiary anilines, efficient electron transfer quenching occurs for both Z and E conformers.The Z conformers form fluorescent exciplexes, providing a new example of exciplex-type emission in the absence of direct ?-? overlap.Exciplexes formed by the E conformers are nonfluorescent and apparently undergo rapid intersystem crossing.The strong exciplex emission observed at low temperatures both in solution and in frozen glasses is attributed to ground state dimers or aggregates.
- Lewis, Frederick D.,Burch, Erick L.
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p. 4055 - 4063
(2007/10/03)
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- The Use of 2-Oxazolidinones as Latent Aziridine Equivalents. 2. Aminoethylation of Aromatic Amines, Phenols, and Thiophenols
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The utility of 2-oxazolidinones 1 as latent, carboxylated aziridine functionalities was examined.Reaction of 2-oxazolidinone (1a), 3-methyl2-oxazolidinone (1b), 3-(phenylmethyl)-2-oxazolidinone (1c), 3-phenyl-2-oxazolidinone (1d) 4,4-dimethyl-2-oxazolidinone (1e), and 5-ethyl-2-oxazolidinone (1f) with aromatic amine salts, phenol, or thiophenols at elevated temperatures (> 130 deg C) afforded aminoethylated adducts.The aminoethylation occurred with concomitant loss of carbon dioxide to furnish variously substituted N-aryl-1,2-ethanediamines 4, 1-(2-phenoxyethyl)-2-imidazolidinone (8), or 2-(arylthio)ethanamines 9 on reactions of 1 with aromatic amine salts, phenol, and thiophenols, respectively.Imidazolidinone 8 is believed to be a secondary reaction product resulting from the condensation of the initially formed 2-phenoxyethanamine with starting oxazolidinone 1a.The aminoethylation reaction did not proceed with aliphatic amine hydrochlorides or alkyl mercaptans.Preliminary mechanistic pathways for these ring openings were also investigated employing a specific, C-5 deuterium-labeled oxazolidinone 1b-d2.Ring-opening experiments of 1b-d2 with N-methylaniline hydrochloride suggest reaction can occur through either a dioxazolinium 5 and/or 5 intermediate.In contrast, reaction of 1b-d2 with thiophenol suggests ring-opening to proceed only via the dioxazolinium pathway.
- Poindexter, Graham S.,Owens, Donald A.,Dolan, Peter L.,Woo, Edmund
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p. 6257 - 6265
(2007/10/02)
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- Mechanistic Studies on Dopamine β-Monooxygenase Catalysis: N-Dealkylation and Mechanism-Based Inhibition by Benzylic-Nitrogen-Containing Compounds. Evidence for a Single-Electron-Transfer Mechanism
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Dopamine β-monooxygenase (DBM) readily catalyzes oxidative N-dealkylation of N-phenylethylenediamine (PEDA) and N-methyl-N-phenylethylenediamine (N-MePEDA) with the reaction characteriscics expected for a monooxygenase-catalyzed process.The products of this reaction have been quantitatively identified as aniline (or N-methylaniline for N-MePEDA) and 2-aminoacetaldehyde, the latter compound being successfully trapped by using NaBH4 reduction followed by N-succinimidyl p-nitriphenylacetate (SNPA) derivatization, and identified by HPLC and mass spectroscopy.In contrast, either analogues of PEDA, i.e. phenyl 2-aminoethyl ether (PAEE) and its p-hydroxy derivative (p-OHPAEE), as well as 2-phenoxycycloprpylamine are not substrates but are competitive inhibitors.Furthermore, 2-methyl-2-anilino-1-aminoethane (β-MePEDA) did not exhibit measurable substrate activity with DBM, in contrast to the excellent substrate activity of the sulfur analogue of β-MePEDA, 2-methyl-2-(phenylthio)-1-aminoethane (β-MePAES).DBM is inactivated during the N-dealkylation reaction in a time- and concentration-dependent manner, a phenomenon that has not, to our knowledge, been observed for any other oxygenase-catalyzed N-dealkylation reaction.Both PEDA and N-MePEDA, as well as β-MePEDA, inactivate DBM under turnover conditions.The inactivation exhibited pseudo-first-order saturable kinetics and expected protection by the DBM substrate, tyramine.No reappearance of enzyme activity was observed after extensive dialysis.Radioactive labeling experiments with ring-tritiated PEDA showed incorporation of nondialyzable radioactivity into DBM in the expected amount, consistent with covalent attachment of a reactive species derivd from PEDA to the DBM active site during enzyme inactivation.Although aniline, N-ethylaniline, N-(2-fluoroethyl)aniline, m- and p-anisidine, p-toluidine, and 5-hydroxyindole were found not to exhibit detectable DBM substrate activity, all of these inactivated the enzyme under turnover conditions.The isotope effect on partition ratio measured for dideuteriated PEDA was found to be a reflection of an isotope effect on Vmax and not on kinact.Our results provide a strong support for the conclusion that the initial nitrogen cation radical species is responsible for enzyme inactivation.Results with ring-deuteriated and ring-tritiated PEDA revealed that the amount of radioactivity incorporated into covalently inactivated DBM by ring-tritiated PEDA is in agreement with that expected for covalent attachment of the para carbon to the protein.An 18O labeling study was carried out to test for oxygen rebound into the aminoacetaldehyde product, and results demonstrated that the aldehyde oxygen of enzymatically produced 2-aminoacetaldehyde exchanges very rapidly with solvent water, in agreement with literature reports.On the basis ...
- Wimalasena, Kandatege,May, Sheldon W.
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p. 4036 - 4046
(2007/10/02)
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- N-(amino)alkyl)-1-pyrrolidine, 1-piperidine and 1-homopiperidinecarboxamides (and thiocarboxamides) with sulfur linked substitution in the 2, 3 or 4-positions
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Novel pyrrolidine, piperidine and homopiperidinecarboxamide and thiocarboxamide compounds having the formula: STR1 wherein X is --S--, --S(O)-- or --S(O)2 --; A is a loweralkalene chain and A1 and A2 are alkalene chains when p and d are one; R, R1 and R2 are hydrogen, loweralkyl, phenyl cycloalkyl or phenylalkyl and R1 and R2 may form a heterocyclic residue with the adjacent nitrogen atom; Q is a selected aromatic radical, and the pharmaceutically acceptable acid addition salts useful as cardiac antiarrhythmia agents are disclosed. Novel chemical intermediates, unsubstituted on pyrrolidine, piperidine and homopiperidine nitrogen but with --(A2)p --X--(A2)d --Q side chain are also disclosed.
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- N-[(amino)alkyl]-1-pyrrolidine, 1-piperidine and 1-homopiperidinecarboxamides (and thiocarboxamides) with sulfur linked substitution in the 2, 3 or 4-position
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Novel pyrrolidine, piperidine and homopiperidinecarboxamide and thiocarboxamide compounds having the formula: STR1 wherein X is --S--, --S(O)-- or --S(O)2 --; A is a loweralkalene chain and A1 and A2 are alkalene chains when p and d are one; R, R1 and R2 are hydrogen, loweralkyl, phenyl cycloalkyl or phenylalkyl and R1 and R2 may form a heterocyclic residue with the adjacent nitrogen atom; Q is a selected aromatic radical, and the pharmaceutically acceptable acid addition salts useful as cardiac antiarrhythmia agents are disclosed. Novel chemical intermediates, unsubstituted on pyrrolidine, piperidine and homopiperidine nitrogen but with --(A2)p --X--(A2)d --Q side chain are also disclosed.
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- Pyrazine derivatives
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Pyrazine derivatives by the formula STR1 are disclosed. In the above formula, R1 and R2, which may be the same or different, each represents a hydrogen atom, a halogen atom, a hydroxy group, a lower alkoxy group, a phenyl lower alkoxy group, a phenoxy group, a mercapto group, a lower alkylthio group, a phenyl lower alkylthio group, a phenylthio group, an amino group, a substituted amino group, a lower alkyl group, a carbamoyl group or a sulfamoyl group; R3 represents a lower alkoxy group; R4, R5, and R6, which may be the same or different, each represents a hydrogen atom, a lower alkyl group, a cycloalkyl group, a phenyl lower alkyl group, or a phenyl group; and A represents a lower alkylene group; said R4 and A, said R5 and A, said R4 and R5, or said R5 and R6 may form a 5-membered or 6-membered nitrogen-containing heterocyclic ring which may further contain a hetero-atom together with nitrogen atom, and the pharmacologically acceptable non-toxic salts thereof. The compounds of this invention have a strong and selective antiematic activity and an effect of stimulating the gastric motility.
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