- Highly Active and Selective Ru-PNH Catalyst in Aerobic Oxidation of Benzyl Amines
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Set of [Ru(η6-cymene)(R)XCl] (R=L1SnCl, L1GeCl L2PPh2, X=Cl or SnCl3, L1=[2-(CH2NEt2)-4,6-(tBu)2C6H2]?, L2=2,6-iPr2-C6H3-NH?) catalysts was tested in aerobic oxidations of primary amines. The activity of studied catalysts depends on the charge of the Ru atom that has been influenced either by donating ligands R or by character of X. Typical Ru/P catalyst [Ru(η6-cymene)(L2PPh2)Cl2] (3) with least negative charge on the Ru atom has been observed as the most effective. The design of the phosphine ligand L2 containing amino-phosphine PNH moiety provided efficient anchoring of complex 3 to silica gel via hydrogen bonding of the PNH functional group to SiO2 to give heterogeneous catalyst 3-silica. This complex has been also efficiently tested in aerobic oxidation as recyclable catalyst with cumulative TON up to 6930.
- Aman, Michal,Tremmel, Jakub,Dostál, Libor,Erben, Milan,Tydlitát, Ji?í,Jansa, Josef,Jambor, Roman
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- Unsymmetrical α,ω-Difunctionalized Long-Chain Compounds via Full Molecular Incorporation of Fatty Acids
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α,ω-Difunctionalized long-chain compounds A-(CH2)n-B are valuable intermediates and monomers. Unsymmetrical compounds with two different functional groups (A ≠ B) are, however, only accessible by multistep traditional organic syntheses to date. We report on their generation in a single step by isomerizing alkoxycarbonylations of the double bond deep in the chain of oleic derivatives. The compatibility with amide, nitrile and imide functionalities in the substrate allows for the formation with high linear selectivities (ca. 90%) and conversions (70 to 96%) of unsymmetric diesters, ester-amides, ester-nitriles and ester-(N-imides) in which these functional groups are terminally attached to a ≥ 17 methylene unit chain. These products further provide access to carboxylic acid-esters, alcohol-esters and amino-esters, and polymers from these AB-monomers. Undesired transesterifications that scramble the A and B functionalities are suppressed completely (0.1%) by the utilization of a Pd(II) catalyst precursor devoid of acid additives in the presence of amine base.
- Witt, Timo,Stempfle, Florian,Roesle, Philipp,H?ussler, Manuel,Mecking, Stefan
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- Synthesis, characterization, catalytic and biological application of half-sandwich ruthenium complexes bearing hemilabile (κ2-: C, S)-thioether-functionalised NHC ligands
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A series of cationic Ru(ii)(η6-p-cymene) complexes with thioether-functionalised N-heterocyclic carbene ligands have been prepared and fully characterized. Steric and electronic influence of the R thioether substituent on the coordination of the sulfur atom was investigated. The molecular structure of three of them has been determined by means of X-ray diffractrometry and confirmed the bidentate (κ2-C,S) coordination mode of the ligand. Interestingly, only a single diastereomer, as an enantiomeric couple, was observed in the solid state for complexes 1c, 1i and 1j. DFT calculations established a low energy inversion barrier between the two diastereomers through a sulfur pyramidal inversion pathway with R donating group while a dissociative/associative mechanism is more likely with R substituents that contain electron withdrawing group, thus suggesting that the only species observed by the 1H-NMR correspond to an average resonance position of a fluxional mixtures of isomers. All these complexes were found to catalyse the oxydant-free double dehydrogenation of primary amine into nitrile. Ru complex bearing NHC-functionalised S-tBu group was further investigated in a wide range of amines and was found more selective for alkyl amine substrates than for benzylamine derivatives. Finally, preliminary results of the biological effects on various human cancer cells of four selected Ru complexes are reported.
- Achard, Thierry,Bellemin-Laponnaz, Stéphane,Chen, Weiguang,Egly, Julien,Maisse-Francois, Aline,Poblador-Bahamonde, Amalia I.
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supporting information
p. 3243 - 3252
(2020/03/19)
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- Ru@UiO-66(Ce) catalyzed acceptorless dehydrogenation of primary amines to nitriles: The roles of Lewis acid-base pairs in the reaction
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UiO-66(Ce)-encapsulated ruthenium nanoparticles (Ru@UiO-66(Ce)) was designed and used for dehydrogenation of primary amines to nitriles in water without any hydrogen acceptors and additives. Introduction of metal Ru to UiO-66(Ce) contributes to the formation of Lewis acid-base pairs on the catalyst owing to the metal-support interaction, acting as active sites for activation of amines and transfer of hydrogen. Ab initio calculation results further confirm the roles of Lewis acid-base pairs in the reaction.
- Lu, Guo-Ping,Li, Xinxin,Zhong, Lixiang,Li, Shuzhou,Chen, Fei
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supporting information
p. 5386 - 5393
(2019/10/11)
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- Easy Ruthenium-Catalysed Oxidation of Primary Amines to Nitriles under Oxidant-Free Conditions
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A dehydrogenation of primary amine to give the corresponding nitrile under oxidant- and base-free conditions catalysed by simple [Ru(p-cym)Cl2]2 with no extra ligand is reported. The system is highly selective for alkyl amines, whereas benzylamine derivatives gave the nitrile product together with the imine in a ratio ranging from 14:1 to 4:1 depending on the substrate. Preliminary mechanistic investigations have been performed to identify the key factors that govern the selectivity.
- Achard, Thierry,Egly, Julien,Sigrist, Michel,Maisse-Fran?ois, Aline,Bellemin-Laponnaz, Stéphane
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supporting information
p. 13271 - 13274
(2019/10/21)
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- Double Dehydrogenation of Primary Amines to Nitriles by a Ruthenium Complex Featuring Pyrazole Functionality
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A ruthenium(II) complex bearing a naphthyridine-functionalized pyrazole ligand catalyzes oxidant-free and acceptorless selective double dehydrogenation of primary amines to nitriles at moderate temperature. The role of the proton-responsive entity on the ligand scaffold is demonstrated by control experiments, including the use of a N-methylated pyrazole analogue. DFT calculations reveal intricate hydride and proton transfers to achieve the overall elimination of 2 equiv of H2.
- Dutta, Indranil,Yadav, Sudhir,Sarbajna, Abir,De, Subhabrata,H?lscher, Markus,Leitner, Walter,Bera, Jitendra K.
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supporting information
p. 8662 - 8666
(2018/07/09)
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- METHOD FOR SYNTHESIZING AN OMEGA-AMINO ACID OR ESTER FROM A MONOUNSATURATED FATTY ACID OR ESTER
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A method for synthesizing ω-amino-alkanoic acids or the esters thereof from natural unsaturated fatty acids passing through an intermediate ω-unsaturated nitrile compound. The method is simple to implement and, relative to known methods, avoids the environmental constraints and economic disadvantages resulting from the reaction by-products. The method includes synthesizing an ω-amino acid (ester) of formula R3OOC—(CH2)q—CH2NH2, in which R3 is H or an n-butyl radical and q is an integral index of between 2 and 13, from a monounsaturated fatty acid (ester) of formula (R1-CH═CH—(CH2)p-COO) xR2, in which x represents 1, 2 or 3, R1 is H or a hydrocarbon radical comprising from 4 to 11 carbon atoms and, where appropriate, a hydroxyl function, R2 is H or an alkyl radical comprising from 2 to 4 carbon atoms, and may contain one or more heteroatoms, and p is an integral index of between 2 and 11, including a reaction step of ammoniation.
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Paragraph 0089; 0090
(2014/07/08)
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- One-pot transformation of carboxylic acids into nitriles
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A variety of aromatic and aliphatic carboxylic acids were smoothly converted into the corresponding nitriles in good yields in a one-pot procedure by treatment with ethyl iodide/K2CO3/18-crown-6, followed by sodium diisobutyl-tert-butoxyaluminium hydride (SDBBA-H), and finally treatment with molecular iodine or 1,3-diiodo-5,5-dimethylhydantoin (DIH), and aqueous ammonia. This method is useful for the conversion of various aromatic and aliphatic carboxylic acids into the corresponding nitriles in a one-pot procedure. A variety of aromatic and aliphatic carboxylic acids were smoothly converted into the corresponding nitriles in good yields in a one-pot procedure by treatment with ethyl iodide/K2CO3/18-crown-6, followed by sodium diisobutyl-tert-butoxyaluminium hydride (SDBBA-H), and finally treatment with molecular iodine or 1,3-diiodo-5,5-dimethylhydantoin (DIH), and aqueous ammonia. Copyright
- Miyagi, Kotaro,Moriyama, Katsuhiko,Togo, Hideo
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p. 5886 - 5892
(2013/09/23)
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- Process for Producing Nitrile-Fatty Acid Compounds
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The invention relates to a process for synthesizing a nitrile-fatty acid (heminitrile) from unsaturated fatty acids, in the form of an acid or a simple ester or a “complex” ester of triglyceride type, which is first of all converted into an unsaturated fatty nitrile which is subjected to oxidative cleavage using H2O2 as oxidizing agent. This process can be used for preparing polyamide monomers, such as ω-amino acids or diamines or diacids equivalent to said heminitrile and for obtaining polyamides from raw materials which are of natural origin and from a renewable source.
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Paragraph 0175-0180
(2014/02/15)
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- Facile transformation of esters to nitriles
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Various esters were efficiently converted into the corresponding nitriles in good yields by the treatment with sodium diisobutyl-tert-butoxyaluminium hydride (SDBBA-H), followed by treatment with molecular iodine in aq ammonia. The present one-pot method is very efficient and practical for the conversion of various aromatic and aliphatic esters into the corresponding nitriles.
- Suzuki, Yusuke,Moriyama, Katsuhiko,Togo, Hideo
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experimental part
p. 7956 - 7962
(2011/11/07)
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- METHOD FOR THE SYNTHESIS OF AN OMEGA-AMINO ACID OR ESTER STARTING FROM A MONOUNSATURATED FATTY ACID OR ESTER
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The invention relates to a method for the synthesis of ω-amino alkanoic acids or esters thereof starting from unsaturated natural fatty acids passing through an ω-unsaturated nitrile intermediate compound.
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Page/Page column 8
(2011/10/04)
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- Direct transformation of N,N-disubstituted amides and isopropyl esters to nitriles
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Various N,N-dimethyl amides, N-methoxy-N-methyl amides, and isopropyl esters were smoothly transformed into the corresponding nitriles in good to moderate yields by the treatment with diisobutylaluminium hydride, followed by treatment with molecular iodine in aq ammonia. The present reactions are novel one-pot and practical methods for the transformation of N,N-disubstituted amides and isopropyl esters into nitriles, through the formation of hemiaminal O-AlBu2 and hemiacetal O-AlBu2, respectively.
- Suzuki, Yusuke,Yoshino, Takumi,Moriyama, Katsuhiko,Togo, Hideo
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experimental part
p. 3809 - 3814
(2011/06/25)
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- Method for Synthesizing an Omega-Amino Acid or Ester from a Monounsaturated Fatty Acid or Ester
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The invention relates to a method for synthesizing ω-aminoalkanoic acids or esters thereof from unsaturated natural fatty acids, passing through a monounsaturated dinitrile intermediate compound. The method of the invention is simple to carry out and, compared to other known methods, avoids the environmental constraints and economic disadvantages due to reaction by-products.
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Page/Page column 7
(2011/12/14)
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- Direct, facile synthesis of acyl azides and nitriles from carboxylic acids using bis(2-methoxyethyl)aminosulfur trifluoride
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A mild, efficient, and practical method for the one-step synthesis of acyl azides from carboxylic acids using bis(2-methoxyethyl)aminosulfur trifluoride is described. The reaction was easily extended to the synthesis of the corresponding nitriles by the inclusion of phosphorous reagents. The method can be applied to the synthesis of optically active nitriles in high yields, and is compatible with fluorous phosphines.
- Kangani, Cyrous O.,Day, Billy W.,Kelley, David E.
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p. 5933 - 5937
(2008/02/10)
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- The invention of radical reactions. Part XXIII new reactions: Nitrile and thiocyanate transfer to carbon radicals from sulfonyl cyanides and sulfonyl isothiocyanates
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Reaction of p-toluenesulphonyl cyanide or methanesulfonyl cyanide with carbon radicals, generated from the corresponding O-acyl-N-hydroxy-2-thiopyridone derivatives by visible light photolysis gives nitriles in good yield. The homolysis products of these sulfonyl nitriles can also be trapped by electron rich olefins. We have also found that carbon radicals react easily with mesyl or tosyl isothiocyanate producing thiocyanates.
- Barton,Jaszberenyi,Theodorakis
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p. 2613 - 2626
(2007/10/02)
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- Radical nitrile transfer with methanesulfonyl cyanide or P-toluenesulfonyl cyanide to carbon radicals generated from the acyl derivatives of N-hydroxy-2-thiopyridone
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Reaction of methanesulfonyl cyanide or p-toluenesulfonyl cyanide with carbon radicals generated from the acyl derivatives of N-hydroxy-2-thiopyridone gives the corresponding nitriles in high yield. A mechanistic scheme is suggested.
- Barton,Jaszberenyi,Theodorakis
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p. 3321 - 3324
(2007/10/02)
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