- A mineralogically-inspired silver-bismuth hybrid material: An efficient heterogeneous catalyst for the direct synthesis of nitriles from terminal alkynes
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The synthesis and characterization of a silver-containing hybrid material is reported as a novel heterogeneous noble metal catalyst. In order to eliminate the need for traditional immobilization techniques, and to create a solid material with structurally-bound silver catalytic centers, the layered structure of a naturally occurring mineral served as the basis of the initial catalyst design. The novel material was prepared by means of the urea-mediated homogeneous precipitation of the corresponding metal nitrates, and was fully characterized by means of diverse instrumental techniques (X-ray diffractometry, Raman, IR, UV-Vis, EPR, X-ray photoelectron spectroscopies, thermal methods as well as atomic force, scanning and transmission electron microscopies). The as-prepared material exhibited outstanding activity in silver-catalyzed CC bond activation to yield organic nitriles directly from terminal alkynes with less environmental concerns as compared to the classical synthesis methods. The effects of the reaction time, the temperature, as well as the role of various solvents, nitrogen sources and additives were carefully scrutinized in order to achieve high-yielding and selective nitrile formation. The heterogeneous nature of the reaction was verified and the solid catalyst was recycled and reused numerous times without loss of its activity or degradation of its structure, thereby offering a sustainable synthetic methodology.
- ?tv?s, Sándor B.,Mészáros, Rebeka,Varga, Gábor,Kocsis, Marianna,Kónya, Zoltán,Kukovecz, ákos,Pusztai, Péter,Sipos, Pál,Pálinkó, István,Fül?p, Ferenc
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p. 1007 - 1019
(2018/03/13)
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- Direct synthesis of nitriles from aldehydes with hydroxylamine-O-sulfonic acid in acidic water
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Herein is reported the selective transformation of aldehydes to nitriles in the presence of hydroxylamine-O-sulfonic acid (NH2OSO3H) as a source of the N atom and acidic water. The reaction works with high yields for a large array of aromatic and aliphatic aldehydes, as well as hindered aldehydes and conjugated aldehydes without purification. The reaction conditions are very mild and tolerate a wide array of functional groups. In principle, the reaction can be completed in vinegar.
- Quinn, Dylan J.,Haun, Graham J.,Moura-Letts, Gustavo
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supporting information
p. 3844 - 3847
(2016/08/02)
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- Synthesis of Nitriles from Aldoximes and Primary Amides Using XtalFluor-E
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The dehydration reaction of aldoximes and amides for the synthesis of nitriles using [Et2NSF2]BF4 (XtalFluor-E) is described. Overall, the reaction proceeds rapidly (normally 1 h) at room temperature in an environmentally benign solvent (EtOAc) with only a slight excess of the dehydrating agent (1.1 equiv). A broad scope of nitriles can be prepared, including chiral nonracemic ones. In addition, in a number of cases, further purification of the nitrile after the workup was not required.
- Keita, Massaba,Vandamme, Mathilde,Paquin, Jean-Fran?ois
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p. 3758 - 3766
(2015/11/28)
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- Pheromones and analogs from Neozeleboria wasps and the orchids that seduce them: a versatile synthesis of 2,5-dialkylated 1,3-cyclohexanediones
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Chiloglottone, a wasp pheromone and attractant of sexually deceptive Chiloglottis orchids, and several structural analogs were synthesized. The synthetic approach is facile, high yielding and versatile, enabling rapid divergence to generate dialkylated analogs of chiloglottone. The key transformation was an organocadmium-mediated desymmetrization of glutaric anhydride derivatives. This library of synthetic 2,5-dialkylated 1,3-cyclohexanediones may assist in future identification of natural products in further species.
- Poldy, Jacqueline,Peakall, Rod,Barrow, Russell A.
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p. 2446 - 2449
(2008/09/20)
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- Rhodococcus nitrile hydratase
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The invention relates to a Rhodococcus polynucleotide cluster which contains nucleotide sequences which encode polypeptides having the activity of a nitrile hydratase, of an auxiliary protein P15K which activates this enzyme and of a cobalt transporter, to transformed microorganisms in which the nucleotide sequences encoding these proteins are present in increased quantity, and to the use of the transformed microorganisms for preparing amides from nitriles.
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- Synthesis of an Isotopically Isomeric Mixture of 1,4,6,8-Tetramethyl2>azulene and Its Thermal Reaction with Dimethyl Acetylenedicarboxylate
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Sodium 2>cyclopentadienide in tetrahydrofuran (THF) has been prepared from the corresponding labelled 2>cyclopentadiene which was synthesized from 13CO2 and (chloromethyl)trimethylsilane (cf.Scheme 10) according to an established procedure.It could be shown that the acetate pyrolysis of cis-cyclopentane-1,2-diyl diacetate (cis-22) at 550 +/- 5 deg under reduced pressure (60 Torr) gives five times as much cyclopentadiene as trans-22.The reaction of sodium 2>cyclopentadienide with 2,4,6-trimethylpyrylium tetrafluoroborate in THF leads to the formation of the statistically expected 2:2:1 mixture of 4,6,8-trimethyl2>-, -2>-, and -2>azulene (20; cf.Scheme 7 and Fig. 1).Formylation and reduction of the 2:2:1 mixture 2>-20 results in the formation of a 1:1:1:1:1 mixture of 1,4,6,8-tetramethyl2>-, -2>-, -2>-, -2>-, and -2>azulene (5; cf.Scheme 8 and Fig. 2).The measured 2J(13C,13C) values of 2>-20 and 2>-5 are listed in Tables 1 and 2.Thermal reaction of the 1:1:1:1:1 mixture 2>-5 with the four-fold amound of dimethyl acetylenedicarboxylate (ADM) at 200 deg in tetralin (cf.Scheme 2) gave 5,6,8,10-tetramethyl-2>heptalene-1,2-dicarboxylate (2>-6a; 22percent), its double-bond-shifted (DBS) isomer 2>-6b (19percent), and the corresponding azulene-1,2-dicarboxylate 7 (18percent).The isotopically isomeric mixture of 2>-6a showed no 1J(13C,13C) at C(5) (cf.Fig. 3).This finding is in agreement with the fact that expected primary tricyclic intermediate 2>-8 exhibits at 200 deg in tetralin only cleavage of the C(1)-C(10) bond and formation of a C(7)-C(10) bond (cf.Schemes 6 and 9), but no cleavage of the C(1)-C(11) bond and formation of a C(7)-C(11)-bond.The limits of detection of the applied method is Y>/= 96percent for the observed process, i.e., 2>-5 + ADM -> 2>-8 -> 2>-9 -> 2>-6a (cf.Scheme 6).
- Fallahpour, Reza-Ali,Hansen, Hans-Juergen
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p. 1419 - 1436
(2007/10/02)
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- Synthesis of 6-Substituted 2-(N-Acetylamino)pyridines and 2-Aminopyridines by Cyclization of 5-Oximinoalkanenitriles
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Oxime derivatives of 5-oxoalkanenitriles (C6 chain or longer) were cyclized in most cases with a combination of AcCl and Ac2O, or Ac2O and HCl to 6-substituted 2-(N-acetylamino)pyridines.Alkaline hydrolysis gave the corresponding 2-aminopyridines in overall yields of 40-65 percent, with the exception of pyridine 3e.Oxime derivatives of 5-oxopentanenitriles did not cyclize but gave glutaronitriles instead.In some experiments with 5-oximinohexanenitrile (1a), 2,4-dimethyl-5-(2-cyanoethyl)oxazole (9) was detected in addition to the main product, 2-(N-acetylamino)-6-methylpyridine (2a).Formation of these compounds can be explained on the basis of a common intermediate 7 formed through rearrangement of the O-acetylated 5-oximinohexanenitrile (4).
- Vijn, Robert J.,Arts, Henricus J.,Maas, Peter J.,Castelijns, Anna M.
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p. 887 - 891
(2007/10/02)
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- ACCELERATION OF SOLID-LIQUID TWO-PHASE REACTION BY MEANS OF ALUMINA-WATER-ULTRASOUND. A SUBSTITUTE FOR A PHASE TRANSFER CATALYST
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Combined use of alumina, a trace of water, and ultrasound greatly accelerated a solid-liquid two-phase nucleophilic substitution by cyanide ion in nonpolar organic solvents.The efficiency under the optimum conditions were compared with that of phase transfer catalysts such as 18-crown-6.
- Ando, Takashi,Kawate, Takehiko,Ichihara, Junko (nee Yamawaki),Hanafusa, Terukiyo
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p. 725 - 728
(2007/10/02)
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- Cyanomethylation versus Reductive Saturation and Hydrodimerisation during the Electroreduction αβ-Unsaturated Nitriles in Acetonitriles
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Results for the electroreduction of cinnamonitrile, 3-methylcinnamonitrile, and acrylonitrile in acetonitrile under a variety of conditions are reported in detail, and the factors which favour the formation of glutaronitrile derivatives (cyanomethylation) versus reductive saturation and hydrodimerization have been identified.Cyanomethylation of acrylonitrile has also been studied using (i) azobenzene-acetonitrile, and (ii) phenylsulphonylacetonitrile-dimethylformamide, as the source of electrogenerated -CH2CN.
- Bellamy, Anthony J.,Kerr, John B.,McGregor, CChristopher J.,MacKirdy, Iain S.
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p. 161 - 168
(2007/10/02)
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- AMMOXYDATION CATALYTIQUE DES HYDROCARBURES ET REACTIONS APPARENTEES. XXII. AMMOXYDATION DU BENZENE ET DU CYCLOHEXANE
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Benzene ammoxidation at 440-550 deg C/1 at. produces, on V-Mo, Ti-Mo, Bi-Mo (oxides) catalysts, unsaturated C4 (maleo and fumaronitriles) and C6 (mucononitrile and stereoisomers) dinitriles.These initial selectivities fall with increasing conversions, and C6 dinitriles disappear above 10percent conversion by thermal or catalytic degradation.The main initial stereoisomer cis-cis (mucononitrile) is consistent with a 1-2 attack of the aromatic ring, so far unknown in catalytic oxidations.Cyclohexane ammoxidation goes through the oxidative dehydrogenation to benzene and proceduces small amounts of C4 unsaturated dinitriles along with traces of C4, C5 and C6 saturated dinitriles coming from a different reaction path.In both cases, V-Mo and Ti-Mo are the best catalysts for dinitriles production; no C6 formed on Sn-Mo, Sb-Mo and Sn-Sb-Fe-catalysts.
- Simon, Gerard,Germain, Jean-Eugene
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p. 149 - 155
(2007/10/02)
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