- Base-Free Oxidative Coupling of Amines and Aliphatic Alcohols to Imines over Au–Pd/ZrO2 Catalyst under Mild Conditions
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Abstract: The base-free synthesis of imines from amines and aliphatic alcohols over Au–Pd alloy catalysts under ambient conditions was developed. A series of Au–Pd/ZrO2 bimetallic catalysts with varying metal loadings and Au?:?Pd molar ratios were prepared and their catalytic performance was investigated. The 3.0?wt?% Au–Pd/ZrO2 alloy catalyst with Au?:?Pd molar ratio of 1?:?1 showed the best catalytic performance. Under air atmosphere, various imines were obtained from coupling of amines and aliphatic alcohols without any additives or promoters. The performance of alloy NPs was superior to that of monometallic catalysts due to the synergistic effect which was demonstrated by TEM, XPS, and UV–Vis characterization. Our work suggested this transformation differed slightly from those reactions between amine and benzyl alcohol and a possible mechanism was proposed. Moreover, the Au–Pd/ZrO2 catalyst could be easily separated and reused for at least five successive runs with high catalytic activity.
- Cui, Wenjing,Jia, Meilin,Sagala,Wang, Jiang
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p. 958 - 967
(2021/06/06)
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- Enantioselective Reductive Cyanation and Phosphonylation of Secondary Amides by Iridium and Chiral Thiourea Sequential Catalysis
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The combination of transition-metal catalysis and organocatalysis increasingly offers chemists opportunities to realize diverse unprecedented chemical transformations. By combining iridium with chiral thiourea catalysis, direct enantioselective reductive cyanation and phosphonylation of secondary amides have been accomplished for the first time for the synthesis of enantioenriched chiral α-aminonitriles and α-aminophosphonates. The protocol is highly efficient and enantioselective, providing a novel route to the synthesis of optically active α-functionalized amines from the simple, readily available feedstocks. In addition, the reactions are scalable and the thiourea catalyst can be recycled and reused.
- Chen, Dong-Huang,Sun, Wei-Ting,Zhu, Cheng-Jie,Lu, Guang-Sheng,Wu, Dong-Ping,Wang, Ai-E,Huang, Pei-Qiang
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supporting information
p. 8827 - 8831
(2021/03/16)
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- Fluorinated matrix metalloproteinases inhibitors - Phosphonate based potential probes for positron emission tomography
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Fluorine-containing inhibitors of matrix metalloproteinases (MMPs) can serve as lead structures for the development of 18F-labeled radioligands. These compounds might be useful as non-invasive imaging probes to characterize pathologies associated with increased MMP activity. Results with a series of fluorinated analogs of a known biphenyl sulfonamide inhibitor have shown that fluorine can be incorporated into two different positions of the molecular scaffold without significant loss of potency in the nanomolar range. Additionally, the potential of a hitherto unknown fluorinated tertiary sulfonamide as MMP inhibitor has been demonstrated.
- Beutel, Bernd,Daniliuc, Constantin G.,Riemann, Burkhard,Sch?fers, Michael,Haufe, Günter
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supporting information
p. 902 - 909
(2016/02/10)
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- Synthesis of imines from amines in aliphatic alcohols on Pd/ZrO2 catalyst under ambient conditions
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Synthesis of imines from amines and aliphatic alcohols (C 1-C6) in the presence of base on supported palladium nanoparticles has been achieved for the first time. The catalytic system shows high activity and selectivity in open air at room temperature.
- Cui, Wenjing,Zhaorigetu, Bao,Jia, Meilin,Ao, Wulan,Zhu, Huaiyong
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p. 2601 - 2604
(2014/01/06)
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- Ruthenium-catalyzed N-alkylation of amines with alcohols under mild conditions using the borrowing hydrogen methodology
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Using a simple amino amide ligand, ruthenium-catalyzed one-pot alkylation of primary and secondary amines with simple alcohols was carried out under a wide range of conditions. Using the alcohol as solvent, alkylation was achieved under mild conditions, even as low as room temperature. Reactions occurred with high conversion and selectivity in many cases. Reactions can also be carried out at high temperatures in organic solvent with high selectivity using stoichiometric amounts of the alcohol.
- Enyong, Arrey B.,Moasser, Bahram
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p. 7553 - 7563
(2014/09/17)
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- Spirocyclic dihydropyridines by electrophile-induced dearomatizing cyclization of N-alkenyl pyridinecarboxamides
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On treatment with acylating or sulfonylating agents, N-alkenyl pyridine carboxamides (N-pyridinecarbonyl enamines) undergo a dearomatizing cyclization initiated by pyridine acylation and followed by intramolecular trapping of the resulting pyridinium cation. The products are spirocyclic dihydropyridines which may be further elaborated to spirocyclic heterocycles with drug-like features.
- Senczyszyn, Jemma,Brice, Heloise,Clayden, Jonathan
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supporting information
p. 1922 - 1925
(2013/06/04)
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- α,β-Unsaturated imines via Ru-catalyzed coupling of allylic alcohols and amines
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A convenient synthesis of α,β-unsaturated imines requiring only an allylic alcohol, an amine and a Ru catalyst has been developed. The use of large excesses of oxidant and the purification of sensitive intermediates can be avoided.
- Rigoli, Jared W.,Moyer, Sara A.,Pearce, Simon D.,Schomaker, Jennifer M.
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supporting information; experimental part
p. 1746 - 1749
(2012/04/23)
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- Synthesis and pharmacological properties of 5-alkyl substituted nicotine analogs
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This paper describes a concise and practical route to enantiomerically enriched 5-alkyl substituted nicotine analogs. The Vilsmeier reaction was used to construct the nicotinaldehydes ring followed by the introduction of the chiral homoallylic alcohol by organic boron reagent and the cyclization of the pyrrolidine ring through the reduction of a chiral azide. 17 analogs have been synthesized and their corresponding biological activities were tested, in which compounds 10d and 10g exhibit excellent IC50 values against RD and SY-SY5Y. Copyright
- Wang, Jing,Li, Xi,Yuan, Qianjia,Ren, Jiangmeng,Huang, Jin,Zeng, Bubing
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p. 2813 - 2818
(2013/08/23)
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- Method of synthesis of phosphinic acids based on hypophosphites: VIII.1 synthesis of α-aminoalkylphenethylphosphinic acids
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Development of methodology of double Arbuzov rearrangement based on hypophosphites allows a one-pot formation of two unsymmetrical phosphorus-carbon bonds by the Michael-Pudovik type reaction of stepwise addition of the intermediately forming silyl esters of trivalent phosphorus to different unsaturated compounds. A procedure was developed of the synthesis of α-aminoalkylphenethylphosphinic acids. Bis-(trimethylsilyl) phenethylphosphonite formed as a result of the addition of bis(trimethylsilyl) hypophosphite to styrene in situ was added without isolation from the reaction mixture to Schiff bases obtained preliminary from benzylamine or diphenylmethylamine and various aldehydes. The subsequent removal of N-protecting groups by hydrogenation or acidic hydrolysis gave a number of new α-aminoalkylphenethylphosphinic acids.
- Dmitriev,Ragulin
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experimental part
p. 1786 - 1791
(2012/01/12)
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- A highly diastereoselective synthesis of α-hydroxy-β-amino acid derivatives via a Lewis acid catalyzed three-component condensation reaction
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A very efficient three-component synthesis of a series of syn α-hydroxy-β-amino esters, obtained in high diastereoselection and yield, was realized starting from an aldehyde, benzylamine, and the ketene silyl acetals derived from Ley's lactones. The synthetic protocol was optimized and the above compounds were obtained without the isolation of intermediates. The origin of the observed diastereoselection was investigated through a computational model of the key reaction step.
- Gassa, Federico,Contini, Alessandro,Fontana, Gabriele,Pellegrino, Sara,Gelmi, Maria Luisa
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experimental part
p. 7099 - 7106
(2010/12/24)
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- A regiospecific approach to N-alkylpyrazoles and the derived N-oxides using 5-endo-dig cyclisations of alkynyl nitrosamines
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5-endo-dig Cyclisations of N-nitroso derivatives of homopropargylic amines, catalysed by silver nitrate on silica gel proceed smoothly at ambient temperature in chlorinated solvents to give essentially quantitative yields of the corresponding pyrazole-N-oxides, deoxygenation of which gives excellent yields of the related N-alkylpyrazoles in a regiospecific manner. Georg Thieme Verlag Stuttgart.
- Hayes, Simon J.,Knight, David W.,O'Halloran, Mark,Pickering, Stuart R.
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experimental part
p. 2188 - 2190
(2009/04/07)
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- Facile and selective synthesis of chloronicotinaldehydes by the Vilsmeier reaction
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Eleven enamides were prepared by adopting different procedures. The various enamides prepared were subjected to Vilsmeier reaction using (i) POCl3/DMF; (ii) diphosgene/DMF; (iii) triphosgene/DMF leading to the formation of various multisubstituted chloronicotinaldehydes. Studies carried out indicate that Vilsmeier reagent concentration and the replacement of POCl3 by diphosgene or triphosgene, provides excellent selectivity and higher yields. Under modified reaction conditions one can get only chloronicotinaldehydes and not the chloropyridines as products. The various advantages in using diphosgene and triphosgene are illustrated. The mechanism of formation of chloronicotinaldehyde was discussed.
- Gangadasu,Narender,Bharath Kumar,Ravinder,Ananda Rao,Ramesh,China Raju,Jayathirtha Rao
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p. 8398 - 8403
(2007/10/03)
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- Single step synthesis of 2,3-dialkyl-6-nitro-quinazolin-4(3H)-imines and 3,5-dialkyl-9-nitro-imidazo[1,2-c]quinazolin-2(3H)-ones
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A single step synthesis of 2,3-dialkyl-6-nitro-quinazolin-4(3H)-imines and 3,5-dialkyl-9-nitro-imidazo-[1,2-c]-quinazolin-2(3H)-ones from simple carbonyl compounds, primary amines or amino acid methyl esters and 2-azido-5-nitro- benzonitrile was developed. Key intermediates were N,N′-disubstituted amidines obtained by rearrangement of 4,5-dihydrotriazoles; the new heterocyclic rings were formed by spontaneous intramolecular reaction of the amino and cyano groups which are present in the intermediates.
- Erba, Emanuela,Pocar, Donato,Trimarco, Pasqualina
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p. 5778 - 5781
(2007/10/03)
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- Base induced carbon-nitrogen (C=N) double bond migration in Schiff bases
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Various Schiff bases have been prepared to study base induced carbon-nitrogen double bond migrations. Schiff bases derived from aliphatic aldehydes display highest selectivity. Hydrolysis of the resulting rearranged Schiff base provides an entry to make amines from aldehydes. The reaction has possible practical application.
- Gangadasu,Narender,China Raju,Jayathirtha Rao
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p. 2598 - 2600
(2007/10/03)
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- SYNTHESIS AND CHARACTERIZATION OF PYRROLINONECARBOXYLATES FORMED BY REACTION OF VICINAL TRICARBONYL DERIVATIVES WITH ALDEHYDE SCHIFF BASES
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A series of vicinal tricarbonyl derivatives undergo reaction with aldehyde Schiff bases forming pyrrolinone derivatives by benzilic acid-related rearrangements.The structures were established by X-ray analyses and, independently by the SESAMI NMR-based computer program.
- Wasserman, Harry H.,Ennis, David S.,Vu, Chi B.,Schulte, Gayle,Munk, Morton E.,et al.
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p. 975 - 995
(2007/10/02)
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- Lithium aluminum amides: New reagents for the synthesis of imines
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Aldehydes (4 eqiv.) react under mild conditions with LiAL(NHR1)4 (1 eqiv.) to give the corresponding imines in 90% yield and no polymerization was observed upon reaction of aliphatic aldehyde 3.
- Solladie-Cavallo,Bencheqroun,Bonne
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p. 1683 - 1687
(2007/10/02)
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- THE CHEMISTRY OF VICINAL TRICARBONYLS. FORMATION OF CARBAZOLE DERIVATIVES
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The indole tricarbonyl derivative 1 reacts wuth Schiff bases 2a-c to form substituted carbazoles 3a-c.
- Wasserman, Harry H.,Duzer, John H. van,Yu, Chi B.
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p. 1609 - 1612
(2007/10/02)
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