- Microwave-assisted dehydration and chlorination using phosphonium salt
-
Microwave-assisted reaction using phosphonium salt for dehydration of primary amides and chlorination of hydroxyheteroaromatics was carried out. Copyright Taylor & Francis, Inc.
- Tanji, Ken-Ichi,Koshio, Jiro,Sugimoto, Osamu
-
-
Read Online
- A convenient preparation of alkyl nitriles by the Mitsunobu procedure
-
A convenient preparation of alkyl nitriles from alcohols extending the use of the Mitsunobu reaction is described. Acetone cyanohydrin is the acidic component and the source of cyanide ion.
- Wilk
-
-
Read Online
- Construction of enantioenriched polysubstituted hexahydropyridazines via a sequential multicatalytic process merging palladium catalysis and aminocatalysis
-
An efficient multicatalytic strategy for the construction of nitrogen-containing heterocycles has been reported. The powerful combination of organic and metal catalysis in a single vessel allowed the formation of enantioenriched polysubstituted cyclic 6-membered hydrazines bearing a quaternary stereocenter in good yields and selectivities.
- Marques,Giardinetti,Marrot,Coeffard,Moreau,Greck
-
-
Read Online
- Switch of reaction pathway induced by solid support and ultrasound
-
The influence of activation methods and solid support on the reaction course of benzyl bromide, KCN, and toluene has been investigated. When KCN is not supported on alumina, the reaction under the mechanical agitation follows the aromatic electrophilic substitution pathway, while the reaction under sonication follows nucleophilic substitution. However, when KCN supported on alumina is employed, only the nucleophilic substitution product is obtained under both ultrasound and mechanical agitation. Copyright Taylor & Francis Group, LLC.
- Doan, Tan L.H.,Le, Thach N.
-
-
Read Online
- A New Synthesis of α-Phenylhomoallylnitriles from β-Nitrostyrene and Allylic Silanes
-
TiCl4-catalyzed addition of allylic silanes to β-nitrostyrene affords γ,δ-unsaturated nitronates which, on treatment with low valent titanium in situ generated from Ti(IV) and zinc, are smoothly converted to γ,δ-unsaturated nitriles in moderate yields.
- Uno, Hidemitsu,Fujiki, Satomi,Suzuki, Hitomi
-
-
Read Online
- Polycationic (Mixed) Core-Shell Dendrimers for Binding and Delivery of Inorganic/Organic Substrates
-
The convergent synthesis of a series of polycationic aryl ether dendrimers has been accomplished by a convenient procedure involving quantitative quaternarization of aryl(poly)amine core molecules. The series has been expanded to the preparation of the first polycationic, mixed core-shell dendrimer. All these dendrimers consist of an apolar core with a peripheral ionic layer which is surrounded by a less polar layer of dendritic wedges. These cationic, macromolecular species have been investigated for their ability to form assemblies with (anionic) guest molecules. The results obtained from UV/Vis and NMR spectroscopies, and MALDI-TOF-MS demonstrate that all the cationic sites throughout the dendrimer core are involved in ion pair formation with anionic guests giving predefined guest/host ratios up to 24. The large NMR spectroscopic shifts of resonances correlated with the groupings located in the core of the dendrimers, together with the relaxation time data indicate that the anionic guests are associated with the cationic core of these dendrimers. The X-ray molecular structure of the octacationic, tetra-arylsilane model derivative [Si(C6H3{CH2NMe3}2-3,5)4](8+) * 8I(-) shows that the iodide counterions are primarily located near the polycationic sphere. The new polycationic dendrimers have been investigated for their catalytic phase-transfer behavior and substrate delivery over a nanofiltration membrane.
- Kleij, Arjan W.,Coevering, Rob van de,Gebbink, Robertus J. M. Klein,Noordman, Anne-Marie,Spek, Anthony L.,Koten, Gerard van
-
-
Read Online
- Ionic liquids as catalytic green solvents for nucleophilic displacement reactions
-
We demonstrate the use of room-temperature ionic liquids as a catalytic, environmentally benign solvent for the cyanide displacement on benzyl chloride, replacing phase-transfer catalyzed biphasic systems and thus eliminating the need for a volatile organic solvent and hazardous catalyst disposal.
- Wheeler,West,Liotta,Eckert
-
-
Read Online
- The hydrogenation of mandelonitrile over a Pd/C catalyst: Towards a mechanistic understanding
-
A carbon supported Pd catalyst is used in the liquid phase hydrogenation of the aromatic cyanohydrin mandelonitrile (C6H5CH(OH)CH2CN) to afford the primary amine phenethylamine (C6H5CH2CH2NH2). Employing a batch reactor, the desired primary amine is produced in 87% selectivity at reaction completion. Detection of the by-product 2-amino-1-phenylethanol (C6H5CH(OH)CH2NH2) accounts for the remaining 13% and closes the mass balance. The reaction mechanism is investigated, with a role for both hydrogenation and hydrogenolysis processes established.
- McAllister, Mairi I.,Boulho, Cédric,McMillan, Liam,Gilpin, Lauren F.,Brennan, Colin,Lennon, David
-
-
Read Online
- BENZYLGLUCOSINOLATE DEGRADATION IN HEAT-TREATED LEPIDIUM SATIVUM SEEDS AND DETECTION OF A THIOCYANATE-FORMING FACTOR
-
Lepidium sativum seeds were dry heated at 125 deg C for varying periods, and also for 30 min at various temperatures.Autolysates were then analysed for benzylglucosinolate degradation products.Whilst heating for 4 hr 20 min at 125 deg C was sufficient to prevent formation of benzyl thiocyanate, just over 7.5 hr at 125 deg C was required before benzyl isothiocyanate also ceased to be produced.This indicates the presence of a discrete, thiocyanate-forming factor in L. sativum seeds, separate from thioglucosidase.After 7.5 hr at 125 deg C, benzyl cyanide continued to be formed, proving that it can be obtained (in relatively small amounts) directly from the glucosinolate even without the influence of any thioglucosidase.In general, isothiocyanate was the more favoured product of glucosinolate degradation following heat treatment of seeds, until the point of thioglucosidase inactivation was approached when nitrile formation took over.It is suggested that the thiocyanate-forming-factor is an isomerase causing Z-E isomerization of the glucosinolate aglucone, but that only those glucosinolates capable of forming particularly stable cations are then able to undergo E-aglucone rearrangement to thiocyanate. Key Word Index- Lepidium sativum; Cruciferae; cress; glucosinolate degradation; thiocyanate.
- Hasapis, Xenophon,MacLeod, Alexander J.
-
-
Read Online
- HPLC-based kinetics assay facilitates analysis of systems with multiple reaction products and thermal enzyme denaturation
-
Glucosinolates are plant secondary metabolites abundant in Brassica vegetables that are substrates for the enzyme myrosinase, a thioglucoside hydrolase. Enzyme-mediated hydrolysis of glucosinolates forms several organic products, including isothiocyanates (ITCs) that have been explored for their beneficial effects in humans. Myrosinase has been shown to be tolerant of non-natural glucosinolates, such as 2,2-diphenylethyl glucosinolate, and can facilitate their conversion to non-natural ITCs, some of which are leads for drug development. An HPLC-based method capable of analyzing this transformation for non-natural systems has been described. This current study describes (1) the Michaelis–Menten characterization of 2,2-diphenyethyl glucosinolate and (2) a parallel evaluation of this analogue and the natural analogue glucotropaeolin to evaluate effects of pH and temperature on rates of hydrolysis and product(s) formed. Methods described in this study provide the ability to simultaneously and independently analyze the kinetics of multiple reaction components. An unintended outcome of this work was the development of a modified Lambert W(x) which includes a parameter to account for the thermal denaturation of enzyme. The results of this study demonstrate that the action of Sinapis alba myrosinase on natural and non-natural glucosinolates is consistent under the explored range of experimental conditions and in relation to previous accounts.
- Klingaman, Chase A.,Wagner, Matthew J.,Brown, Justin R.,Klecker, John B.,Pauley, Ethan H.,Noldner, Colin J.,Mays, Jared R.
-
-
Read Online
- Passflow syntheses using functionalized monolithic polymer/glass composites in flow-through microreactors
-
A chemist's wish finally becomes reality: microreactors for every synthetic laboratory! By precipitation polymerization various polymers are introduced into the irregular pore system of a porous glass rod. By embedding these rods into a housing, followed by functionalization and immobilization of reagents onto the polymer phase, versatile microreactors are obtained. With this apparatus, chemical transformations in solution can be performed, for example, a steroid derivatization (see picture).
- Kirschning, Andreas,Altwicker, Carsten,Drger, Gerald,Harders, Jan,Hoffmann, Nora,Hoffmann, Ulrich,Schnfeld, Hagen,Solodenko, Wladimir,Kunz, Ulrich
-
-
Read Online
- Calixarene ionic liquids: Excellent phase transfer catalysts for nucleophilic substitution reaction in water
-
The first examples of calixarene ionic liquids 3 and 6 with 3D-shaped cavities were obtained in high yields by reacting calix[4]arene or thiacalix[4]arene with 1,6-dibromohexane and then refluxing in 1-methylimidazole. The experiments of phase transfer catalysis in water suggested that they possessed excellent catalytic properties of aromatic nucleophilic substitution reaction and benzyl nucleophilic substitution. The optimized yields of product in catalytic reaction were as high as approximate 97% under mild reaction conditions. The cavities of calixarene skeleton played the crucial roles in catalysis and the stable cone conformation was favorable for catalysis.
- Yang, Fafu,Guo, Hongyu,Jiao, Ziyu,Li, Congcong,Ye, Jinqi
-
-
Read Online
- The reduction of α,β-unsaturated nitriles and α-halonitriles with sodium hydrogen telluride
-
Sodium hydrogen telluride reacts chemoselectively with α,β- unsaturated nitriles and α-halonitriles linked to aromatic and aliphatic substituents to corresponding saturated nitriles with good yields.
- Blay, Gonzalo,Cardona, Luz,Garcia, Begona,Lahoz, Luisa,Pedro, Jose R.
-
-
Read Online
- A poly(ethylene glycol)-supported quaternary ammonium salt: An efficient, recoverable, and recyclable phase-transfer catalyst
-
(matrix presented) A quaternary ammonium salt readily immobilized on a soluble poly(ethylene glycol) polymer support efficiently catalyzes different reactions carried out under phase-transfer catalysis conditions; the catalyst, easily recovered by precipitation and filtration, shows no appreciable loss of activity when recycled three times.
- Annunziata, Rita,Benaglia, Maurizio,Cinquini, Mauro,Cozzi, Franco,Tocco, Graziella
-
-
Read Online
- Mechanisms of Polymer-Supported Catalysis. 2. Reaction of Benzyl Bromide with Aqueous Sodium Cyanide Catalyzed by Polystyrene-Bound Onium Ions
-
Rates of reaction of benzyl bromide in toluene with aqueous sodium cyanide in triphase mixtures with polystyrene-supported benzyltrimethylammonium and benzyltri-n-butylphosphonium ions as phase-transfer catalysts depend upon mechanical stirring speed, catalyst particle size, and percent of cross-linking of the polymer support.Increases in stirring speed increase reaction rates up to a maximum at about 600 rpm.Decreases in particle size increase reaction rates.Increases in polymer cross-linking decrease reaction rates.Apparent activation energies with benzyltrimethylammoniumion catalyst are 12 - 15 kcal/mol at 70 - 90 deg C.Rates of reaction of benzyl bromide, benzyl chloride, 1-bromooctane, and 1-bromohexadecane all are affected differently by variations in catalyst structure, particle size, and cross-linking.The results are discussed in terms of mass transfer, intraparticle diffusion, and intrinsic reactivity limitations on reaction rates.Slow intraparticle diffusion reduces the reactivity differences between benzyl bromide and 1-bromooctane and between benzyl bromide and benzyl chloride and causes 1-bromohexadecane to react much slower than 1-bromooctane.
- Tomoi, M.,Ford, Warren T.
-
-
Read Online
- EFFECTS OF METAL IONS ON BENZYLGLUCOSINOLATE DEGRADATION IN LEPIDIUM SATIVUM SEED AUTOLYSATES
-
The effects of varying concentrations of Fe2+ (5E-5 - 5E-1 M) on benzylglucosinolate degradation in Lepidium sativum seed autolysates were investigated.Increased glucosinolate decomposition was observed over the whole range with a maximum effect at ca. 6E-3 M Fe2+, at which point glucosinolate degradation was more than three times that obtained in the absence of added Fe2+.Nitrile formation was especially enhanced in the presence of all concentrations of Fe2+ studied, and maximum amounts were obtained at ca. 6E-3 M Fe2+, when a more than four-fold increase over quantities produced in the absence of Fe2+ was observed.Thiocyanate formation was also promoted with a maximum at ca. 4E-3 M Fe2+, but isothiocyanate production was considerably reduced in all cases.It is suggested that Fe2+ inhibits isothiocyanate formation by interfering with the availability of ascorbic acid which is a proven co-factor for most thioglucosidase isoenzymes, but that an Fe2+-ascorbate complex might then be responsible for promoting enzymic production of nitrile.The effects of a limited range of concentrations of Fe3+ and Cu+ were also studied, and results related to those for Fe2+ The relevance of the findings to natural systems and to glucosinolate-containing foods is briefly discussed.Key Word Index-Lepidium sativum; Cruciferae; glucosinolate degradation.
- Hasapis, Xenophon,MacLeod, Alexander J.
-
-
Read Online
- From Stoichiometric Reagents to Catalytic Partners: Selenonium Salts as Alkylating Agents for Nucleophilic Displacement Reactions in Water
-
The ability of chalcogenium salts to transfer an electrophilic moiety to a given nucleophile is well known. However, up to date, these reagents have been used in stoichiometric quantities, producing a substantial amount of waste as byproducts of the reaction. In this report, we disclose further investigation of selenonium salts as S-adenosyl-L-methionine (SAM) surrogates for the alkylation of nucleophiles in aqueous solutions. Most importantly, we were able to convert the stoichiometric process to a catalytic system employing as little as 10 mol % of selenides to accelerate the reaction between benzyl bromide and other alkylating agents with sodium cyanide in water. Probe experiments including 77Se NMR and HRMS of the reaction mixture have unequivocally shown the presence of the selenonium salt in the reaction mixture. (Figure presented.).
- Martins, Nayara Silva,ángel, Alix Y. Bastidas,Anghinoni, Jo?o M.,Lenard?o, Eder J.,Barcellos, Thiago,Alberto, Eduardo E.
-
supporting information
p. 87 - 93
(2021/11/03)
-
- Radical trifunctionalization of hexenenitrile via remote cyano migration
-
A novel radical-mediated trifunctionalization of hexenenitriles via the strategy of remote functional group migration is disclosed. A portfolio of functionalized hexenenitriles are employed as substrates. After difunctionalization of the unactivated alken
- Chang, Chenyang,Wu, Xinxin,Zhang, Huihui,Zhu, Chen
-
supporting information
p. 1005 - 1008
(2022/02/01)
-
- Metal-Free Deoxygenation of Chiral Nitroalkanes: An Easy Entry to α-Substituted Enantiomerically Enriched Nitriles
-
A metal-free, mild and chemodivergent transformation involving nitroalkanes has been developed. Under optimized reaction conditions, in the presence of trichlorosilane and a tertiary amine, aliphatic nitroalkanes were selectively converted into amines or nitriles. Furthermore, when chiral β-substituted nitro compounds were reacted, the stereochemical integrity of the stereocenter was maintained and α-functionalized nitriles were obtained with no loss of enantiomeric excess. The methodology was successfully applied to the synthesis of chiral β-cyano esters, α-aryl alkylnitriles, and TBS-protected cyanohydrins, including direct precursors of four active pharmaceutical ingredients (ibuprofen, tembamide, aegeline and denopamine).
- Pirola, Margherita,Faverio, Chiara,Orlandi, Manuel,Benaglia, Maurizio
-
p. 10247 - 10250
(2021/06/18)
-
- Accelerated Discovery of α-Cyanodiarylethene Photoswitches
-
Cyanodiarylethene chromophores are able to undergo constitutional exchange via dynamic covalent chemistry (DCC). During this process, the central ethylene bridge of the molecular scaffold can be broken and thereby enables the assembly of a new combination of aryl moieties around the reformed ethylene bridge. The reversible CC double bond exchange has exemplarily been investigated using α-cyanostilbenes. Establishing a dynamic equilibrium reaction from α-cyanodiarylethene with arylacetonitriles under mild conditions has been the basis to access constitutional libraries of new photoswitches with potentially improved properties. When subject to irradiation with light of adequate wavelength, α-cyanodiarylethenes undergo Z/E isomerization followed by ring-closure. By screening the thus accessible dynamic chromophore libraries using a desired detection wavelength, we could identify specific dithienyl analogues that exhibit three-state photochromism. The combination of dynamic constitutional libraries of functional chromophores in combination with the light-guided screening and selection should lead to more rapid exploration of structural diversity dye chemistry.
- Hecht, Stefan,K?nig, Niklas F.,Mutruc, Dragos
-
supporting information
p. 9162 - 9168
(2021/07/01)
-
- Bis-morpholinophosphorylchloride, a novel reagent for the conversion of primary amides into nitriles
-
Bis-morpholinophosphorylchloride (Bmpc), in the presence of a base, is an efficient dehydrating agent for both aromatic and aliphatic primary amides, and gives corresponding nitriles under mild conditions in god yields and purity. During the reaction the enantiomeric integrity remains intact.
- Rao, P. Purnachandra,Nowshuddin, Shaik,Jha, Anjali,Rao, B. Leela Maheswara,Divi, Murali K.,Rao
-
supporting information
(2021/01/21)
-
- Facile dehydration of primary amides to nitriles catalyzed by lead salts: The anionic ligand matters
-
The synthesis of nitrile under mild conditions was achieved via dehydration of primary amide using lead salts as catalyst. The reaction processes were intensified by not only adding surfactant but also continuously removing the only by-product, water from the system. Both aliphatic and aromatic nitriles can be prepared in this manner with moderate to excellent yields. The reaction mechanisms were obtained with high-level quantum chemical calculations, and the crucial role the anionic ligand plays in the transformations were revealed.
- Ruan, Shixiang,Ruan, Jiancheng,Chen, Xinzhi,Zhou, Shaodong
-
-
- Method for dehydrating primary amide into nitriles under catalysis of cobalt
-
The invention provides a method for dehydrating primary amide into nitrile. The method comprises the following steps: mixing primary amide (II), silane, sodium triethylborohydride, aminopyridine imine tridentate nitrogen ligand cobalt complex (I) and a reaction solvent under the protection of inert gas, carrying out reacting at 60-100 DEG C for 6-24 hours, and post-treating reaction liquid to obtain a nitrile compound (III). According to the invention, an effective method for preparing nitrile compounds by cobalt-catalyzed primary amide dehydration reaction by using the novel aminopyridine imine tridentate nitrogen ligand cobalt complex catalyst is provided; and compared with existing methods, the method has the advantages of simple operation, mild reaction conditions, wide application range of reaction substrates, high selectivity, stable catalyst, high efficiency, and relatively high practical application value in synthesis.
- -
-
Paragraph 0072-0074
(2021/06/21)
-
- SO2F2-mediated oxidation of primary and tertiary amines with 30% aqueous H2O2 solution
-
A highly efficient and selective oxidation of primary and tertiary amines employing SO2F2/H2O2/base system was described. Anilines were converted to the corresponding azoxybenzenes, while primary benzylamines were transformed into nitriles and secondary benzylamines were rearranged to amides. For tertiary amine substrates quinolines, isoquinolines and pyridines, their oxidation products were the corresponding N-oxides. The reaction conditions are very mild and just involve SO2F2, amines, 30% aqueous H2O2 solution, and inorganic base at room temperature. One unique advantage is that this oxidation system is just composed of inexpensive inorganic compounds without the use of any metal and organic compounds.
- Liao, Xudong,Zhou, Yi,Ai, Chengmei,Ye, Cuijiao,Chen, Guanghui,Yan, Zhaohua,Lin, Sen
-
supporting information
(2021/11/01)
-
- Photochemical Radical C–H Halogenation of Benzyl N-Methyliminodiacetyl (MIDA) Boronates: Synthesis of α-Functionalized Alkyl Boronates
-
α-Haloboronates are useful organic synthons that can be converted to a diverse array of α-substituted alkyl borons. Methods to α-haloboronates are limiting and often suffer from harsh reaction conditions. Reported herein is a photochemical radical C-H halogenation of benzyl N-methyliminodiacetyl (MIDA) boronates. Fluorination, chlorination, and bromination reactions were effective by using this protocol. Upon reaction with different nucleophiles, the C?Br bond in the brominated product could be readily transformed to a series of C?C, C?O, C?N, C?S, C?P, and C?I bonds, some of which are difficult to forge with α-halo sp2-B boronate esters. An activation effect of B(MIDA) moiety was found.
- Yang, Ling,Tan, Dong-Hang,Fan, Wen-Xin,Liu, Xu-Ge,Wu, Jia-Qiang,Huang, Zhi-Shu,Li, Qingjiang,Wang, Honggen
-
p. 3454 - 3458
(2020/12/17)
-
- Catalytic Asymmetric Cyanoalkylation of Electron-Deficient Olefins with Potassium Cyanide and Alkyl Halides
-
The stereoselective cyanoalkylation of electron-deficient olefins with potassium cyanide and alkyl halides was developed based on the utilization of modular chiral 1,2,3-triazolium salts featuring a hydrogen bond-donor ability as catalysts. The reaction involving multiple carbon-carbon bond formations proceeds via the enantioselective conjugate addition of a cyanide ion and the consecutive catalyst-controlled diastereoselective alkylation of intermediary chiral triazolium enolates. Control experiments revealed that the use of a properly tuned chiral triazolium ion as a catalyst and the presence of the cyano functionality in the intermediary enolate are of crucial importance for achieving high levels of acyclic absolute and relative stereocontrol.
- Kiyokawa, Mari,Morita, Yusuke,Ohmatsu, Kohsuke,Ooi, Takashi
-
supporting information
p. 11218 - 11224
(2021/08/03)
-
- Iodine Promoted Conversion of Esters to Nitriles and Ketones under Metal-Free Conditions
-
We report a novel strategy to prepare valuable nitriles and ketones through the conversion of esters under metal-free conditions. By using the I2/PCl3 system, various substrates including aliphatic and aromatic esters could react with acetonitrile and arenes to afford the desired products in good to excellent yields. This method is compatible with a number of functional groups and provides a simple and practical approach for the synthesis of nitrile compounds and aryl ketones.
- Xiao, Jing,Guo, Fengzhe,Li, Yinfeng,Li, Fangshao,Li, Qiang,Tang, Zi-Long
-
p. 2028 - 2035
(2021/02/03)
-
- A Titanium-Catalyzed Reductive α-Desulfonylation
-
A titanium(III)-catalyzed desulfonylation gives access to functionalized alkyl nitrile building blocks from α-sulfonyl nitriles, circumventing traditional base-mediated α-alkylation conditions and strong single electron donors. The reaction tolerates numerous functional groups including free alcohols, esters, amides, and it can be applied also to the α-desulfonylation of ketones. In addition, a one-pot desulfonylative alkylation is demonstrated. Preliminary mechanistic studies indicate a catalyst-dependent mechanism involving a homolytic C?S cleavage.
- Kern, Christoph,Selau, Jan,Streuff, Jan
-
p. 6178 - 6182
(2021/03/16)
-
- Cyclometalated Platinum(II) Complexes with Nitrile and Isocyanide Ligands: Synthesis, Structure, and Photophysical Properties
-
Abstract: A series of cyclometalated platinum(II) complexes with nitrile and isocyanide ligands (RCN and RNC; R = t-Bu, Bn, Ph) have been synthesized in 60–80% yields from the dimer [{Pt(ppy)Cl}2] (Hppy is 2-phenylpyridine) and the corresponding nitriles and isocyanides. The structure of the synthesized complexes was determined by mass spectrometry, IR and NMR spectroscopy, and X-ray diffraction. The contributions of different intermolecular interactions to the crystal packing were estimated by Hirshfeld surface analysis. Photophysical properties of the synthesized complexes in solution and solid state were studied.
- Katkova,Eliseev,Mikherdov,Sokolova,Starova,Kinzhalov
-
p. 393 - 400
(2021/04/26)
-
- Direct C(sp3)-H Cyanation Enabled by a Highly Active Decatungstate Photocatalyst
-
A highly efficient, direct C(sp3)-H cyanation was developed under mild photocatalytic conditions. The method enabled the direct cyanation of various C(sp3)-H substrates with excellent functional group tolerance. Notably, complex natural products and bioactive compounds were efficiently cyanated.
- Kim, Kunsoon,Lee, Seulchan,Hong, Soon Hyeok
-
supporting information
p. 5501 - 5505
(2021/07/26)
-
- Hydrosilylative reduction of primary amides to primary amines catalyzed by a terminal [Ni-OH] complex
-
A terminal [Ni-OH] complex1, supported by triflamide-functionalized NHC ligands, catalyzes the hydrosilylative reduction of a range of primary amides into primary amines in good to excellent yields under base-free conditions with key functional group tolerance. Catalyst1is also effective for the reduction of a variety of tertiary and secondary amides. In contrast to literature reports, the reactivity of1towards amide reduction follows an inverse trend,i.e., 1° amide > 3° amide > 2° amide. The reaction does not follow a usual dehydration pathway.
- Bera, Jitendra K.,Pandey, Pragati
-
supporting information
p. 9204 - 9207
(2021/09/20)
-
- Silicon hydrogenation reaction method of organic boron and inorganic alkali catalysis amide (by machine translation)
-
The method is characterized in that organic boron and inorganic bases are used as catalysts, silane is used as a reducing agent, primary amide is reduced to primary amine or dehydration dinitrile, the secondary amide is reduced to a secondary amine or aldimine, and the tertiary amide is reduced to tertiary amine. The method has the advantages of simple operation, mild reaction conditions, wide substrate universality, good functional group compatibility and the like, and has the characteristics of good stability, cheap and accessible catalyst, simple and convenient operation, high practicality and the like. (by machine translation)
- -
-
Paragraph 0201-0207; 0249-0252
(2020/08/18)
-
- Method for continuous preparation of nitriles in a pipelined reactor (by machine translation)
-
The method comprises the following steps that a tin catalyst is coated on the inner wall of the pipeline reactor; and the method comprises the following steps: coating a tin catalyst on the inner wall of the pipeline reactor. The amide solution and the catalytic auxiliary agent are mixed and then sent to a pipeline reactor, and the amide is dehydrated to generate nitrile at the reaction pressure of 0.1 - 2.0 mpa and 100 - 200 °C reaction temperature. The resulting reaction product was separated to give the crude product of the nitrile to which the amide corresponded. In the pipeline reactor, the corresponding nitrile is continuously prepared under the action of the tin catalyst, a dehydrating agent is not needed, byproducts only are water, and three wastes are reduced. (by machine translation)
- -
-
Paragraph 0036-0047; 0056; 0058
(2020/12/14)
-
- Synthesis of nitriles via the iodine-mediated dehydrosulfurization of thioamides
-
A simple general method for the synthesis of nitriles using the inexpensive and easy to handle iodine (I2) is described herein. The reaction of thioamides with I2 in the presence of triethylamine at room temperature under aerobic conditions afforded various nitriles bearing aryl, vinyl, and alkyl groups in good-to-excellent yields. This method was also effective for conversion from thioureas to cyanamides.
- Murata, Yuki,Iwasa, Hitomi,Matsumura, Mio,Yasuike, Shuji
-
p. 679 - 681
(2020/07/30)
-
- NHC-catalyzed silylative dehydration of primary amides to nitriles at room temperature
-
Herein we report an abnormal N-heterocyclic carbene catalyzed dehydration of primary amides in the presence of a silane. This process bypasses the energy demanding 1,2-siloxane elimination step usually required for metal/silane catalyzed reactions. A detailed mechanistic cycle of this process has been proposed based on experimental evidence along with computational study.
- Ahmed, Jasimuddin,Hota, Pradip Kumar,Maji, Subir,Mandal, Swadhin K.,Rajendran, N. M.
-
supporting information
p. 575 - 578
(2020/01/29)
-
- Lewis acid promoted dehydration of amides to nitriles catalyzed by [PSiP]-pincer iron hydrides
-
The dehydration of primary amides to their corresponding nitriles using four [PSiP]-pincer hydrido iron complexes 1–4 [(2-Ph2PC6H4)2MeSiFe(H)(PMe3)2 (1), (2-Ph2PC6H4)2HSiFe(H)(PMe3)2 (2), (2-(iPr)2PC6H4)2HSiFe(H)(PMe3)2 (3) and (2-(iPr)2PC6H4)2MeSiFe(H)(PMe3)2 (4)] as catalysts in the presence of (EtO)3SiH as dehydrating reagent was explored in the good to excellent yields. It was proved for the first time that Lewis acid could significantly promote this catalytic system under milder reaction conditions than other Lewis acid-promoted system, such as shorter reaction time or lower reaction temperature. This is also the first example that dehydration of primary amides to nitriles was catalyzed by silyl hydrido iron complexes bearing [PSiP]-pincer ligands with Lewis acid as additive. This catalytic system has good tolerance for many substituents. Among the four iron hydrides 1 is the best catalyst. The effects of substituents of the [PSiP]-pincer ligands on the catalytic activity of the iron hydrides were discussed. A catalytic reaction mechanism was proposed. Complex 4 is a new iron complex and was fully characterized. The molecular structure of 4 was determined by single crystal X-ray diffraction.
- Chang, Guoliang,Li, Xiaoyan,Zhang, Peng,Yang, Wenjing,Li, Kai,Wang, Yajie,Sun, Hongjian,Fuhr, Olaf,Fenske, Dieter
-
-
- An Air-Stable N-Heterocyclic [PSiP] Pincer Iron Hydride and an Analogous Nitrogen Iron Hydride: Synthesis and Catalytic Dehydration of Primary Amides to Nitriles
-
An air-stable N-heterocyclic PSiP pincer iron hydride FeH(PMe3)2(SiPh(NCH2PPh2)2C6H4) (4) was synthesized by Si-H activation of a Ph-substituted [PSiP] pincer ligand. The analogous strong electron-donating iPr-substituted [PSiP] pincer ligand was prepared and introduced into iron complex to give an iron nitrogen complex FeH(N2)(PMe3)(SiPh(NCH2PiPr2)2C6H4) (6). Both 4 and 6 showed similar high efficiency for catalytic dehydration of primary amides to nitriles. Air-stable iron hydride 4 was the best catalyst for its stabilization and convenient preparation. A diverse range of cyano compounds including aromatic and aliphatic species was obtained in moderate to excellent yields. A plausible catalytic reaction mechanism was proposed.
- Fenske, Dieter,Fuhr, Olaf,Li, Xiaoyan,Sun, Hongjian,Wang, Yajie,Xie, Shangqing,Zhang, Hua
-
-
- Method for continuous preparation of nitriles by amides (by machine translation)
-
The method comprises the following steps: preparing a lead salt supported by a molecular sieve by a lead salt and a molecular sieve through an impregnation method; and filling a molecular sieve-loaded lead catalyst into a fixed bed reactor. The amide or amide solution is sent into a fixed bed reactor from the top of the fixed bed to be subjected to catalytic dehydration, and the obtained reaction product is led out from the bottom of the fixed bed. The reaction product is separated to obtain the crude product of the nitrile corresponding to the amide. A fixed bed continuous production process is adopted, the reaction process is simple, the production efficiency is high, the product post-treatment is simple, and industrial production is easy to realize. (by machine translation)
- -
-
Paragraph 0033-0054; 0061-0066
(2020/12/15)
-
- Ruthenium(II)-Complex-Catalyzed Acceptorless Double Dehydrogenation of Primary Amines to Nitriles
-
Acceptorless dehydrogenative oxidation of primary amines into nitriles using an in situ complex derived from commercially available dichloro(1,5-cyclooctadiene) ruthenium(II) complex and simple hexamethylenetetramine has been demonstrated. The synthetic protocol is highly selective and yields the nitrile compounds in moderate to excellent yields and produces hydrogen as the sole byproduct.
- Kannan, Muthukumar,Muthaiah, Senthilkumar
-
supporting information
p. 1073 - 1076
(2020/07/04)
-
- Acceptorless dehydrogenation of amines and alcohols using simple ruthenium chloride
-
A highly efficient, economic and environmental friendly catalyst system has been developed for the dehydrogenation of alcohols and amines using simple RuCl3·nH2O and N-benzylhexamethylenetetramine. The in situ catalyst system efficiently oxidized the primary and secondary amines and secondary alcohols into nitrile, imine and ketone products, respectively in moderate to excellent yields. The developed catalyst system was also found to be efficient for the dehydrogenation of N-heterocyles. A detailed mechanism study revealed the first example of N-benzylhexamethylenetetramine (HMTA-Bz) being simultaneously acting as base, reducing agent and hydride source to generate the [Ru(II)(H)2] species as the active catalyst. The mechanism studies also revealed both the alcohol and amine oxidation involves dehydrogenative pathway with the evolution of hydrogen as the only by-product. The developed catalyst system also provides possible platform for the release of hydrogen from liquid organic hydrogen carriers (LOHCs).
- Barteja, Parul,Devi, Preeti,Kannan, Muthukumar,Muthaiah, Senthilkumar
-
-
- HCl·DMPU-assisted one-pot and metal-free conversion of aldehydes to nitriles
-
We report an efficient HCl·DMPU assisted one-pot conversion of aldehydes into nitriles. The use of HCl·DMPU as both an acidic source as well as a non-nucleophilic base constitutes an environmentally mild alternative for the preparation of nitriles. Our protocol proceeds smoothly without the use of toxic reagents and metal catalysts. Diverse functionalized aromatic, aliphatic and allylic aldehydes incorporating various functional groups were successfully converted to nitriles in excellent to quantitative yields. This protocol is characterized by a broad substrate scope, mild reaction conditions, and high scalability. This journal is
- Hammond, Gerald B.,Mudshinge, Sagar R.,Potnis, Chinmay S.,Xu, Bo
-
supporting information
p. 4161 - 4164
(2020/07/14)
-
- Chlorotropylium Promoted Conversions of Oximes to Amides and Nitriles
-
Chlorotropylium chloride as a catalyst for the transformations of oximes, ketones, and aldehydes to their corresponding amides and nitriles in excellent yields (up to 99 %) and in short reaction times (mostly 10–15 min). Oximes were electrophilically attacked on the hydroxyl oxygen by chlorotropylium. The produced tropylium oxime ethers were the key intermediates, of which the ketoxime ether led to amide through Beckmann rearrangement, and the aldoxime ether led to nitrile by nitrogen base DBU assisted formal dehydration. This chlorotropylium activation protocol offered general, mild, and efficient avenues bifurcately from oximes to both amides and nitriles by one organocatalyst.
- Xu, Jiaxi,Gao, Yu,Li, Zhenjiang,Liu, Jingjing,Guo, Tianfo,Zhang, Lei,Wang, Haixin,Zhang, Zhihao,Guo, Kai
-
p. 311 - 315
(2020/01/25)
-
- SO2F2-Mediated one-pot cascade process for transformation of aldehydes (RCHO) to cyanamides (RNHCN)
-
A simple, mild and practical cascade process for the direct conversion of aldehydes to cyanamides was developed featuring a wide substrate scope and great functional group tolerability. This method allows for transformations of readily available, inexpensive, and abundant aldehydes to highly valuable cyanamides in a pot, atom, and step-economical manner with a green nitrogen source. This protocol will serve as a robust tool for the installation of the cyanamide moiety in various complicated molecules.
- Ding, Chengrong,Ge, Shuting,Wei, Junjie,Zhang, Guofu,Zhao, Yiyong
-
p. 17288 - 17292
(2020/05/18)
-
- Efficient dehydration of primary amides to nitriles catalyzed by phosphorus-chalcogen chelated iron hydrides
-
A series of phosphorus-chalcogen chelated hydrido iron (II) complexes 1–7, (o-(R'2P)-p-R-C6H4Y)FeH (PMe3)3 (1: R = H, R' = Ph, Y = O; 2: R = Me, R' = Ph, Y = O; 3: R = H, R' = iPr, Y = O; 4: R = Me, R' = iPr, Y = O; 5: R = H, R' = Ph, Y = S; 6: R = Me, R' = Ph, Y = S; 7: R = H, R' = Ph, Y = Se), were synthesized. The catalytic performances of 1–7 for dehydration of amides to nitriles were explored by comparing three factors: (1) different chalcogen coordination atoms Y; (2) R' group of the phosphine moiety; (3) R substituent group at the phenyl ring. It is confirmed that 5 with S as coordination atom has the best catalytic activity and 7 with Se as coordination atom has the poorest catalytic activity among complexes 1, 5 and 7. Electron-rich complex 4 is the best catalyst among the seven complexes and the dehydration reaction was completed by using 2 mol% catalyst loading at 60 °C with 24 hr in the presence of (EtO)3SiH in THF. Catalyst 4 has good tolerance to many functional groups. Among the seven iron complexes, new complexes 3 and 4 were obtained via the O-H bond activation of the preligands o-iPr2P(C6H4)OH and o-iPr2P-p-Me-(C6H4)OH by Fe(PMe3)4. Both 3 and 4 were characterized by spectroscopic methods and X-ray diffraction analysis. The catalytic mechanism was experimentally studied and also proposed.
- Li, Kai,Sun, Hongjian,Yang, Wenjing,Wang, Yajie,Xie, Shangqing,Li, Xiaoyan,Fuhr, Olaf,Fenske, Dieter
-
-
- Preparation method of alkyl nitrile compound
-
The invention discloses a preparation method of an alkyl nitrile compound shown as formula I. The preparation method comprises the following step: in a solvent, in the presence of an additive, carrying out substitution reaction as shown in the specification on a cyanation reagent and an alkyl halide shown as formula II to obtain the alkyl nitrile compound shown as formula I, wherein the cyanationreagent is Zn (CN) 2 and/or Cu (CN) 2; the additive is one or more of an inorganic base, an organic base and a quaternary ammonium salt.
- -
-
Paragraph 0116-0118
(2020/05/14)
-
- Synthetic method of phenylacetonitrile
-
The invention belongs to the technical field of organic chemical synthesis, and particularly relates to a phenylacetonitrile synthesis method which comprises the following steps: adding benzyl chloride into a four-neck glass reaction bottle provided with a mechanical stirrer, a thermometer, a condenser and a constant-pressure dropping funnel, stirring, and sequentially adding a solvent, an acid-binding agent and a phase transfer catalyst; stirring, reducing the reaction temperature to 20 DEG C or below, and slowly dropwise adding hydrocyanic acid; controlling the reaction temperature to be below 20 DEG C after the dripping is finished, and reacting for 1-10 hours; raising the temperature to 30-100 DEG C, and keeping the temperature to react for 1-10 hours; and cooling to room temperature,discharging, filtering, and rectifying a filtrate to obtain phenylacetonitrile. According to the method, the step of preparing sodium cyanide from hydrocyanic acid is omitted, and the technological process is greatly shortened; the reaction is carried out in an inert solvent, so that the reaction is thorough; synthesis is carried out at a low temperature under anhydrous conditions, by-products arefew, and the product yield is high; as an anhydrous system is used for synthesis, the discharge amount of wastewater is greatly reduced.
- -
-
Paragraph 0037-0053
(2020/06/02)
-
- Reductive cyanation of organic chlorides using CO2 and NH3 via Triphos–Ni(I) species
-
Cyano-containing compounds constitute important pharmaceuticals, agrochemicals and organic materials. Traditional cyanation methods often rely on the use of toxic metal cyanides which have serious disposal, storage and transportation issues. Therefore, there is an increasing need to develop general and efficient catalytic methods for cyanide-free production of nitriles. Here we report the reductive cyanation of organic chlorides using CO2/NH3 as the electrophilic CN source. The use of tridentate phosphine ligand Triphos allows for the nickel-catalyzed cyanation of a broad array of aryl and aliphatic chlorides to produce the desired nitrile products in good yields, and with excellent functional group tolerance. Cheap and bench-stable urea was also shown as suitable CN source, suggesting promising application potential. Mechanistic studies imply that Triphos-Ni(I) species are responsible for the reductive C-C coupling approach involving isocyanate intermediates. This method expands the application potential of reductive cyanation in the synthesis of functionalized nitrile compounds under cyanide-free conditions, which is valuable for safe synthesis of (isotope-labeled) drugs.
- Dong, Yanan,Li, Yuehui,Yang, Peiju,Zhao, Shizhen
-
-
- Compound containing carbon-silicon bond and application thereof
-
The invention discloses a compound containing a carbon-silicon bond and application of the compound in construction of the carbon-carbon bond. The invention provides an application of a compound containing the carbon-silicon bond as shown in a formula I or a formula I' in a chemical reaction for constructing the carbon-carbon bond, wherein one carbon in the carbon-carbon bond is from carbon connected with silicon in the compound containing the carbon-silicon bond. According to the preparation method, the compound containing the carbon-silicon bond is used for providing a carbon free radical, and the carbon free radical can directly react with carbon provided in another molecule under a mild condition to construct the carbon-carbon bond; the preparation method is wider in substrate application range, is suitable for functional group activated C and carbon free radical substrates, and is also suitable for unactivated C-H bond substrates.
- -
-
Paragraph 0422-0425
(2020/09/08)
-
- A rings-in-pores net: Crown ether-based covalent organic frameworks for phase-transfer catalysis
-
We herein present a new family of crown ether-based covalent organic frameworks (CE-COFs) for the first time. The CE-COFs show excellent phase-transfer catalytic performance in various nucleophilic substitution reactions.
- Guo, Wen-Di,Hu, Bingwen,Jiang, Wei-Ling,Lou, Xiaobing,Ma, De-Li,Qi, Qiao-Yan,Shen, Ji-Chuang,Shen, Ming,Yang, Hai-Bo,Zhao, Xin
-
supporting information
p. 595 - 598
(2020/01/29)
-
- Method for preparing nitrile by reacting acetone cyanohydrin with haloalkane
-
The invention provides a method for preparing nitrile by reacting acetone cyanohydrin with haloalkane. According to the invention, by using acetone cyanohydrin as a cyaniding reagent, the problems, such as long reaction time, low yield, strict reaction conditions and the like enchanted in an existing preparation method in which highly toxic sodium cyanide or potassium cyanide or expensive trimethylsilyl cyanide is used as a cyanogen source, are solved. The method comprises the following steps: dissolving acetone cyanohydrin in a mixed solvent of a high boiling point dipolar aprotic solvent anda low boiling point aprotic solvent, adding a catalyst lithium hydroxide, stirring at 25-50 DEG C for one hour and then adding a haloalkane for continuous reaction for 2-3 hours; next, adding saturated saline water for washing twice, separating out an organic layer, and boiling off the solvent after drying, thereby obtaining a nitrile compound. The method for preparing a nitrile compound disclosed in the invention is characterized by low reaction toxicity, simple process, easy of operation, low production cost, and a yield of more than 95%.
- -
-
Paragraph 0043-0049; 0050
(2019/08/20)
-
- Direct Synthesis of Nitriles from Carboxylic Acids Using Indium-Catalyzed Transnitrilation: Mechanistic and Kinetic Study
-
Aliphatic and aromatic carboxylic acids can be quantitatively converted to the corresponding nitriles in the presence of catalysts using acetonitrile both as a solvent and reactant at 200 °C. This transformation is based on the acid-nitrile exchange (i.e., transnitrilation) and uses a nontoxic and water resistant catalyst, indium trichloride (InCl3). The mechanism of the transnitrilation was investigated both experimentally and computationally and compared to the previously proposed mechanism. In contrast to the usually assumed formation of amide as an intermediate, transnitrilation is an equilibrium reaction and proceeds via an equilibrated Mumm reaction with the formation of an imide as an intermediate. A simple and reversible mechanism was proposed for this reaction, which was validated by kinetics measurement and by density functional theory calculations of the reaction intermediates and reaction mechanisms.
- Vanoye, Laurent,Hammoud, Ahmad,Gérard, Hélène,Barnes, Alexandra,Philippe, Régis,Fongarland, Pascal,De Bellefon, Claude,Favre-Réguillon, Alain
-
p. 9705 - 9714
(2019/10/14)
-
- Triphenylbismuth Dichloride-Mediated Conversion of Thioamides to Nitriles
-
Thioamides were efficiently converted to nitriles using the pentavalent triphenylbismuth dichloride in combination with triethylamine. The reaction involved the dehydrosulfurization of primary thioamides to afford substituted aromatic or aliphatic nitriles in good to excellent yields. The process was also successfully extended to the synthesis of cyanamides starting from the corresponding thioureas and of thiocyanates from dithiocarbamates.
- Gopi, Elumalai,Gravel, Edmond,Doris, Eric
-
supporting information
p. 4043 - 4045
(2019/06/24)
-
- Identification of an Active NiCu Catalyst for Nitrile Synthesis from Alcohol
-
Development of heterogeneous catalysts for alcohol transformation into nitriles under oxidant-free conditions is a challenge. Considering the C-H activation on α-carbon of primary alcohols is the rate-determining step, decreasing the activation energy of C-H activation is critical in order to enhance the catalytic activity. Several NiM/Al2O3 bimetallic catalysts were synthesized and scrutinized in catalytic transformation of 1-butanol to butyronitrile. Ni-Cu was identified as a suitable combination with the optimized Ni0.5Cu0.5/Al2O3 catalyst exhibiting 10 times higher turnover frequency than Ni/Al2O3 catalyst. X-ray absorption spectroscopy (XAS) and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) revealed that the NiCu particles in the catalyst exist in the form of homogeneous alloys with an average size of 8.3 nm, providing an experimental foundation to build up a catalyst model for further density functional theory (DFT) calculations. Calculations were done over a series of NiM catalysts, and the experimentally observed activity trend could be rationalized by the Br?nsted-Evans-Polanyi (BEP) principle, i.e., catalysts that afford reduced reaction energy also feature lower activation barriers. The calculated activation energy (Ea) for C-H activation with coadsorbed NH3 dropped from 63.4 kJ/mol on pure Ni catalyst to 49.9 kJ/mol on the most active NiCu-2 site in NiCu bimetallic catalyst, in good agreement with the experimentally measured activation energy values. The Ni0.5Cu0.5/Al2O3 catalyst was further employed to convert 11 primary alcohols into nitriles with high to near-quantitative yields, at a Ni loading 10 times less than that of the conventional Ni/Al2O3 catalyst.
- Wang, Yunzhu,Furukawa, Shinya,Yan, Ning
-
p. 6681 - 6691
(2019/07/12)
-
- A BEt3-Base catalyst for amide reduction with silane
-
Reported herein is the development of a simple but practical catalytic system for the selective reduction of amides with hydrosilane or hydrosiloxane. Low-cost and readily available triethylborane (1.0 M in THF), in combination with a catalytic amount of an alkali metal base, was found to catalyze the reduction of all three amide classes (tertiary, secondary, and primary amides) to form amines under mild conditions. In addition, the selective transformation of secondary amides to aldimines and primary amides to nitriles can also be achieved by using a proper combination of BEt3 and base. The scope of these BEt3-base-catalyzed amide hydrosilylation reactions has been explored in depth. Preliminary results of mechanistic studies suggest a modified Piers' silane Si-H···B activation mode wherein the hydride abstraction by BEt3 is promoted by the coordination of an alkoxide or hydroxide anion to the Si center.
- Yao, Wubing,Fang, Huaquan,He, Qiaoxing,Peng, Dongjie,Liu, Guixia,Huang, Zheng
-
-
- A BEt3-Base Catalyst for Amide Reduction with Silane
-
Reported herein is the development of a simple but practical catalytic system for the selective reduction of amides with hydrosilane or hydrosiloxane. Low-cost and readily available triethylborane (1.0 M in THF), in combination with a catalytic amount of an alkali metal base, was found to catalyze the reduction of all three amide classes (tertiary, secondary, and primary amides) to form amines under mild conditions. In addition, the selective transformation of secondary amides to aldimines and primary amides to nitriles can also be achieved by using a proper combination of BEt3 and base. The scope of these BEt3-base-catalyzed amide hydrosilylation reactions has been explored in depth. Preliminary results of mechanistic studies suggest a modified Piers' silane Si-H···B activation mode wherein the hydride abstraction by BEt3 is promoted by the coordination of an alkoxide or hydroxide anion to the Si center.
- Yao, Wubing,Fang, Huaquan,He, Qiaoxing,Peng, Dongjie,Liu, Guixia,Huang, Zheng
-
p. 6084 - 6093
(2019/05/24)
-
- Extending the Chemistry of Hexamethylenetetramine in Ruthenium-Catalyzed Amine Oxidation
-
A very efficient, highly atom economical, and environmentally benign oxidation of primary and secondary amines using an in situ catalyst system generated from commercially available ruthenium(II) benzene dichloride dimer and hexamethylenetetramine has been demonstrated. Mechanistic studies revealed that hexamethylenetetramine acted as a source of hydride to generate the active ruthenium hydride catalyst and amine oxidation involves a dehydrogenative pathway. In comparison to reported catalyst systems for the dehydrogenative oxidation of amines, this synthetic protocol makes use of a simple ruthenium precursor and a cheaper additive; it is very selective, leading to the exclusive formation of nitrile/imine compounds. Further, it releases hydrogen as the only side product, suggesting the potential application of the developed catalyst system in hydrogen storage.
- Kannan, Muthukumar,Muthaiah, Senthilkumar
-
supporting information
p. 3560 - 3567
(2019/11/13)
-
- Selective oxidation of exogenous substrates by a bis-Cu(III) bis-oxide complex: Mechanism and scope
-
Cu(III)2(μ-O)2 bis-oxides (O) form spontaneously by direct oxygenation of nitrogen-chelated Cu(I) species and constitute a diverse class of versatile 2e?/2H+ oxidants, but while these species have attracted attention as biomimetic models for dinuclear Cu enzymes, reactivity is typically limited to intramolecular ligand oxidation, and systems exhibiting synthetically useful reactivity with exogenous substrates are limited. OTMPD (TMPD = N1, N1, N3, N3-tetramethylpropane-1,3-diamine) presents an exception, readily oxidizing a diverse array of exogenous substrates, including primary alcohols and amines selectively over their secondary counterparts in good yields. Mechanistic and DFT analyses suggest substrate oxidation proceeds through initial axial coordination, followed by rate-limiting rotation to position the substrate in the Cu(III) equatorial plane, whereupon rapid deprotonation and oxidation by net hydride transfer occurs. Together, the results suggest the selectivity and broad substrate scope unique to OTMPD are best attributed to the combination of ligand flexibility, limited steric demands, and ligand oxidative stability. In keeping with the absence of rate-limiting C–H scission, OTMPD exhibits a marked insensitivity to the strength of the substrate Cα–H bond, readily oxidizing benzyl alcohol and 1-octanol at near identical rates.
- Large, Tao A.G.,Mahadevan, Viswanath,Keown, William,Stack, T. Daniel P.
-
p. 782 - 792
(2019/01/03)
-
- Ru@UiO-66(Ce) catalyzed acceptorless dehydrogenation of primary amines to nitriles: The roles of Lewis acid-base pairs in the reaction
-
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
-
supporting information
p. 5386 - 5393
(2019/10/11)
-
- Continuous-flow synthesis of nitriles from aldehydes via Schmidt reaction
-
A continuous-flow synthesis of nitriles by Schmidt reaction has been developed. Using this procedure, a variety of aldehydes could be smoothly transformed into the desired nitriles in good to excellent yields. The mild reaction conditions and the flowing reaction system greatly improved the safety and make the reaction easy to scale up.
- Zhan, Wei,Tong, Meng,Ji, Ling,Zhang, Han,Ge, Zemei,Wang, Xin,Li, Runtao
-
p. 973 - 976
(2019/01/29)
-
- SO 2 F 2 -Promoted Dehydration of Aldoximes: A Rapid and Simple Access to Nitriles
-
A rapid, simple and mild process for the dehydration of aldoximes to give the corresponding nitriles, which utilizes SO 2 F 2 as an efficient reagent, has been developed. A variety of (hetero)arene, alkene, alkyne and aliphatic aldoximes proceeded with high efficiency to afford nitriles in excellent to quantitative yields with great functional group compatibilities in acetonitrile under ambient conditions. Furthermore, an eco-friendly synthetic protocol to access nitriles from aldehydes with ortho -, meta - and para -nitrile groups was also described in aqueous methanol by using inorganic base Na 2 CO 3, and a one-pot synthetic strategy to generate nitriles from aldehydes was proved to be feasible.
- Ding, Chengrong,Mei, Guangyao,Wang, Haibo,Zhang, Guofu,Zhao, Yiyong
-
p. 1484 - 1488
(2019/07/15)
-
- Iron and Phenol Co-Catalysis for Rapid Synthesis of Nitriles under Mild Conditions
-
A mild, scalable, high yielding, and rapid route to access diverse nitriles from aldehyde oxime esters enabled by iron(III) and phenol co-catalysis has been developed. The reaction was performed at room temperature to give nitriles in excellent yield within minutes. Mechanistic studies show that the reaction may proceed through a radical process in which benzoyl aldehyde oxime is not only a substrate, but also an ancillary ligand to support iron salt in the promotion of the transformation.
- Meng, Hong,Gao, Sen,Luo, Meiming,Zeng, Xiaoming
-
p. 4617 - 4623
(2019/07/15)
-
- Cascade Process for Direct Transformation of Aldehydes (RCHO) to Nitriles (RCN) Using Inorganic Reagents NH2OH/Na2CO3/SO2F2 in DMSO
-
A simple, mild, and practical process for direct conversion of aldehydes to nitriles was developed feathering a wide substrate scope and great functional group tolerability (52 examples, over 90% yield in most cases) using inorganic reagents (NH2OH/Na2CO3/SO2F2) in DMSO. This method allows for transformations of readily available, inexpensive, and abundant aldehydes to highly valuable nitriles in a pot, atom, and step-economical manner without transition metals. This protocol will serve as a robust tool for the installation of cyano-moieties to complicated molecules.
- Fang, Wan-Yin,Qin, Hua-Li
-
p. 5803 - 5812
(2019/05/14)
-
- Thiocyanate radical mediated dehydration of aldoximes with visible light and air
-
We developed a new means of activating aldoximes by an in situ generated thiocyanate radical from ammonium thiocyanate and molecular oxygen at room temperature. With a catalytic amount of organic dye aizenuranine as the photocatalyst, the dehydration of aldoximes proceeds smoothly under visible light irradiation, providing a simple to handle, excellent functional group tolerance, and metal-free protocol for a wide range of nitriles.
- Ban, Yong-Liang,Dai, Jian-Ling,Jin, Xiao-Ling,Zhang, Qing-Bao,Liu, Qiang
-
supporting information
p. 9701 - 9704
(2019/08/15)
-
- An Insight into Nitromethane as an Organic Nitrile Alternative Source towards the Synthesis of Aryl Nitriles
-
Directed by an unusual in situ reduction of CuII, our protocol is a simple CuI-mediated synthesis of aryl nitriles, with inexpensive and readily available nitromethane as the cyanating source, in moderate to good yields. Exhibiting a wide substrate scope, the method involves simple reaction conditions, is additive free with low catalyst loading. The plausible mechanism of cyanation of aryl halides is elucidated by a congregation of three cycles, namely the in situ reduction of CuII species by nitromethane, generation of HCN species from nitromethane and a regular organometallic pathway which releases the nitrile derivative. The detail of the mechanism of generation of CN– from nitromethane is computationally validated. Our protocol holds the distinction of involving a rarely encountered CuI catalytic species as well as facile in situ generation of nucleophilic CN– to yield synthetically useful aromatic nitriles.
- Saikia, Rakhee,Dey Baruah, Satyajit,Deka, Ramesh C.,Thakur, Ashim J.,Bora, Utpal
-
p. 6211 - 6216
(2019/11/05)
-
- One-Pot Anodic Conversion of Symmetrical Bisamides of Ethylene Diamine to Unsymmetrical gem-Bisamides of Methylene Diamine
-
Symmetrical bisamides of ethylene diamine of type ArCONHCH2CH2NHCOAr undergo anodic C-C bond cleavage in acetonitrile-LiClO4 under controlled-potential electrolysis. The electrogenerated carbocation intermediates react with the solvent acetonitrile to afford unsymmetrical gem-bisamides of type ArCONHCH2NHCOMe in a one-pot reaction. The yields of the latter products are moderate (up to 60%). Other minor products involve two symmetrical gem-bisamides of type ArCONHCH2NHCOAr and MeCONHCH2NHCOMe and fragmentation products (e.g., ArCONHCHO, ArCONH2, and ArCN).
- Golub, Tatiana,Dou, Gui-Yuan,Zeng, Cheng-Chu,Becker, James Y.
-
p. 7961 - 7964
(2019/10/11)
-
This product is a nationally controlled contraband, and the Lookchem platform doesn't provide relevant sales information.
