- Simplified preparation of a graphene-co-shelled Ni/NiO@C nano-catalyst and its application in theN-dimethylation synthesis of amines under mild conditions
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The development of Earth-abundant, reusable and non-toxic heterogeneous catalysts to be applied in the pharmaceutical industry for bio-active relevant compound synthesis remains an important goal of general chemical research.N-methylated compounds, as one of the most essential bioactive compounds, have been widely used in the fine and bulk chemical industries for the production of high-value chemicals. Herein, an environmentally friendly and simplified method for the preparation of graphene encapsulated Ni/NiO nanoalloy catalysts (Ni/NiO@C) was developed for the first time, for the highly selective synthesis ofN-methylated compounds using various functional amines and aldehydes under easy to handle, and industrially applicable conditions. A large number of primary and secondary amines (more than 70 examples) could be converted to the correspondingN,N-dimethylamines with the participation of different functional aldehydes, with an average yield of over 95%. A gram-scale synthesis also demonstrated a similar yield when compared with the benchmark test. In addition, it was further proved that the catalyst could easily be recycled because of its intrinsic magnetism and reused up to 10 times without losing its activity and selectivity. Also, for the first time, the tandem synthesis ofN,N-dimethylamine products in a one-pot process, using only a single earth-abundant metal catalyst, whose activity and selectivity were more than 99% and 94%, respectively, for all tested substrates, was developed. Overall, the advantages of this newly developed method include operational simplicity, high stability, easy recyclability, cost-effectiveness of the catalyst, and good functional group compatibility for the synthesis ofN-methylation products as well as the industrially applicable tandem synthesis process.
- Liu, Jianguo,Ma, Longlong,Song, Yanpei,Zhang, Mingyue,Zhuang, Xiuzheng
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supporting information
p. 4604 - 4617
(2021/06/30)
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- Cp*Ir complex bearing a flexible bridging and functional 2,2′-methylenebibenzimidazole ligand as an auto-tandem catalyst for the synthesis of N-methyl tertiary amines from imines via transfer hydrogenation/N-methylation with methanol
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A Cp*Ir complex bearing a flexible bridging and functional 2,2′-methylenebibenzimidazole ligand was designed, synthesized, and found to be a general and efficient auto-tandem catalyst for the synthesis of N-methyl tertiary amines from imines via transfer hydrogenation/N-methylation with methanol as both hydrogen source and methylating reagent. In the presence of [Cp*Ir(2,2′-CH2BiBzImH2)Cl][Cl], a range of desirable products were obtained in high yields with nearly complete selectivities. The reaction is highly attractive due to the highly atom economy, and minimal consumption of chemicals and energy. Notably, this research exhibits new potential of metal–ligand bifunctional catalysts for the activation of methanol as C1 source for organic synthesis.
- Ai, Yao,Chen, Xiaozhong,Li, Feng,Liu, Peng,Yang, Chenchen,Yang, Jiazhi
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p. 325 - 334
(2021/10/07)
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- Multimodal Anion Exchange Matrices
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The invention discloses a separation matrix which comprises a plurality of separation ligands, defined by the formula R1-L1-N(R3)-L2-R, immobilized on a support, wherein R1 is a five- or six-membered, substituted or non-substituted ring structure or a hydroxyethyl or hydroxypropyl group; L1 is either a methylene group or a covalent bond; R2 is a five- or six-membered, substituted or non-substituted ring structure; L2 is either a methylene group or a covalent bond; R3 is a methyl group; and wherein if R1 is a hydroxyethyl group and L1 is a covalent bond, R2 is a substituted aromatic ring structure or a substituted or non-substituted aliphatic ring structure.
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Paragraph 0081; 0083; 0087
(2015/11/23)
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- Formation of benzylamines from triazene compounds via a 1,2-proton shift
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A new approach to benzylamines using triazene compounds has been developed that is facilitated by the lithiation of aryltriazenes followed by treatment with an electrophile. The regioselectivity of the reaction can be controlled by means of the substituents in the aryl group. The reaction contains the following steps: intramolecular carbon-carbon bond formation involving lithiation of an alkyl group on a 3-nitrogen atom; a 1,2-proton shift; and the subsequent release of nitrogen gas. Through the use of a deuterated triazene, we were able to determine that the reaction proceeds through a 1,2-proton shift.
- Nishiwaki, Keiji,Ogawa, Takashi,Shigeta, Kazumi,Takahashi, Koichi,Matsuo, Keizo
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p. 7034 - 7042
(2007/10/03)
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- Efficient synthesis of tertiary amines from secondary amines
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Reliable N-alkylations of secondary amines have been developed. By using DIAD and TPP (or PS-TPP) a variety of secondary amines can be converted to the corresponding tertiary amines in good to excellent yields with diverse alkylhalides; no formation of quaternary amine salts are observed. These protocols are amenable to combinatorial chemistry libraries, and are also useful for the syntheses of secondary amines by an acid lysis of the cleavable tertiary amino resins.
- Kurosu, Michio,Dey, Sevendu Sekhar,Crick, Dean C.
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p. 4871 - 4875
(2007/10/03)
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- α-lithiation of 1-Aryl-3,3-dialkyltriazenes and intramolecular conversion to benzylamine and tetrahydrobenzotriazine derivatives
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An alternative route to benzylamine derivatives is provided by the lithiation of aryltriazenes followed by treatment with an electrophile [Eq. (1)]. The regioselectivity of the reaction can be controlled by means of the substituents X. When the 2- and 6-p
- Nishiwaki, Keiji,Ogawa, Takashi,Matsuo, Keizo
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p. 484 - 486
(2007/10/03)
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- Catalytic amination of aldehydes to amides
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Aldehydes react in a disproportionation reaction in the presence of rhodium catalysts to yield amines and amides. By adding N-methylmorpholine N-oxide as an oxidant in the presence of catalytic amounts of rhodium, the oxidative amination of aldehydes proceeds selectively to give the corresponding amide. Both aliphatic and aromatic aldehydes react with secondary amines to yield carboxylic acid amides in good to excellent yields.
- Tillack, Annegret,Rudloff, Ivo,Beller, Matthias
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p. 523 - 528
(2007/10/03)
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- A general synthesis of amines and hydrazines by oxidation of amidocuprates and zinc-amidocuprates
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A wide range of amines and hydrazines were synthesized according to an electrophilic amination protocol by oxidative decomposition of readily generated lithium- and zinc-amidocyanocuprates. Optimization of the yields was achieved by the appropriate combination of the organometallic cluster and the nature of the oxidizing agent.
- Cane,Brancaleoni,Dembech,Ricci,Seconi
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p. 545 - 548
(2007/10/03)
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- Oxidative intramolecular coupling of amidocuprates as a novel route to amines and hydrazines
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Amidocuprates, derived from organocopper reagents and lithium amides upon exposure to oxygen at low temperature, provide new amine derivatives in satisfactory yields. Details of this flexible and simple methodology are given. The reaction mechanism is analyzed in terms of an oxidative intramolecular coupling of aminyl radicals with the ligands on Cu in the intermediate amidocuprate. This reaction is a mild and efficient method for N-alkylation, -vinylation, and -arylation by which a number of amines, not easily accessible by normal routes, can be synthesized. Once applied to lithium hydrazides, it also provides a new and straightforward entry to N-substituted hydrazines.
- Alberti, Angelo,Cane, Francesco,Dembech, Pasquale,Lazzari, Dario,Ricci, Alfredo,Seconi, Giancarlo
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p. 1677 - 1681
(2007/10/03)
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- Composition for treating depression with (N-heteroaryl)alkylamines
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The invention concerns compounds having formula: STR1 or a salt thereof, wherein E represents hydrogen, lower alkyl or a group Ar 1 --A 1 --; Ar and Ar 1 are the same or different aryl groups (including heteroaryl) which are optionally substituted, eg by one or more substituents commonly used in pharmaceutical chemistry; A and A 1 are the same or different alkylene groups having one or two carbon atoms linking Ar or Ar 1 to N and optionally substituted by lower alkyl and/or optionally substituted aryl, B is an alkylene group of 3 or 4 carbon atoms, which may be substituted by lower alkyl; D 1 represents halogen, CH 3, CR 1 R 2 NH 2, SO 3 H or SO 2 NR 6 R 7 where R 1 and R 2 are independently hydrogen or lower alkyl and R 6 and R 7 are each hydrogen, lower alkyl or aralkyl of 7 to 12 carbon atoms or R 6 and R 7 together with the nitrogen atom to which they are attached represent a 5 or 6 membered ring, which compounds are useful, for treating depression or cerebral insufficiency or dementias in animals.
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- Composition for treating depression with aralkyl amines
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The invention concerns compounds having formula: STR1 or a salt thereof, wherein E represents hydrogen, lower alkyl or a group Ar1 --A1 ; Ar and Ar1 are the same or different aryl groups (including heteroaryl) which are op
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- CATALYTIC ALKYL GROUP EXCHANGE REACTION OF PRIMARY AND SECONDARY AMINES.
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It has been shown that primary and secondary amines undergo alkyl group exchange reactions upon treatment with palladium catalyst as depicted in an operationally simple and efficient reaction which provides a convenient method for synthesis of unsymmetrical amines. The application of the reaction for the preparation of various substituted amines and heterocyclic compounds such as hexahydropyrimidine tetrahydropyrimidine, imidazolidine, and imidazoles is described. The preparation of polyamines such as H//2N(CH//2)//mNH(CH//2)//nNH//2 (10) and H//2N(CH//2)//lNH(CH//2)//mNH(CH//2)//nNH//2 (l-n, equals 2,3; 11) is readily performed by the appadium-catalyzed reactions of azetidine (6) and aziridine (7) via azetine (9) and azirine intermediates. The mechanism the palladium-catalyzed reaction has been extensively studied on the carbonylation, racemization, and deuteurium-exchange reaction of (S)-( minus )- alpha -phenylethylamine (17).
- Murahashi,Yoshimura,Tsumiyama,Kojima
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p. 5002 - 5011
(2007/10/02)
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- Spectroscopic and chemical reactivity manifestations of strong hydrogen bonding: HCNH proton-proton coupling and alkylation reactions of amines
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Two useful but quite different manifestations of strong hydrogen bonding in systems containing NH groups are reported and discussed.The pKa limit for observation of proton-proton HNCH spin-spin coupling in N-methylanilines is shown to be related to the strength of added H-bond electron donors so that PH3PO, Ph3AsO, and F- in particular are useful reagents for resolving this type of coupling.The mechanism of hydrogen exchange between anilines and water and the role of the added electron donors are discussed.Strong H-bonding between anilines or benzylamines and F- causes pronounced changes in the chemical reactivity of the amine.Results of experiments on the alkylation of these amines using potassium and tetra-n-butylammonium fluorides demonstrate the synthetic utility of this effect.
- Clark, James H.,Pile, James D.,Miller, Jack M.,Paone, Sergio,Tan, Shwe Y.
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p. 1815 - 1820
(2007/10/02)
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