- Phosphine-catalyzed hydration and hydroalkoxylation of activated olefins: Use of a strong nucleophile to generate a strong base
-
The direct addition of water and a variety of alcohols to activated olefins was observed in the presence of nucleophilic phosphine catalysts. Unlike existing methods, the reactions proceed at room temperature and in the absence of transition metals, or strong acids or bases. The use of simple commercially available catalysts makes this an attractive method for the preparation of β-hydroxy and β-alkoxy substrates, which are prevalent targets and intermediates in organic synthesis. The scope and mechanism of this reaction has been explored, and the compound that acts as the resting state of the catalyst was synthesized independently. Our mechanism also suggests the possibility of extending the scope of this reactivity to other classes of nucleophiles. Copyright
- Stewart, Ian C.,Bergman, Robert G.,Toste, F. Dean
-
-
Read Online
- Addition of alcohols to acrylic compounds catalyzed by Mg-Al LDH
-
This study reports the preparation of hydrotalcite with Mg/Al molar ratio 3 by co-precipitation under low suprasaturation conditions of Mg and Al nitrated solutions with Na2CO3 and NaOH at pH 10. The solid was thermally decomposed at 460°C in air atmosphere in order to obtain mixed oxides which, by means of memory effect, can reconstruct the hydrotalcite structure by hydration with bidistilled water. The hydrotalcite and reconstructed samples by memory effect were characterized by elemental analysis, powder XRD, DRIFT and TG-DTG. Determination of the catalysts surface base sites was made using a method based on the irreversible adsorption of organic acids with different pKa values and N2 adsorption-desorption isotherms. The catalytic activity of these solids was evaluated in 1,4-addition of saturated linear alcohols to different acrylic compounds. All these reactions arose with high selectivity in the desired product. No by-products were detected by means of GC-MS chromatography and 1H NMR.
- Teodorescu,Deaconu,Bartha,Z?voianu,Pavel
-
-
Read Online
- Preparation method of 3-methoxypropylamine
-
The invention discloses a preparation method of 3-methoxylpropylamine. The method comprises the following steps: carrying out addition on methanol and acrylonitrile to prepare a 3-methoxylpropionitrile crude product, and then carrying out catalytic hydrogenation on the crude product by using a Raney catalyst to prepare the 3-methoxylpropylamine. In the addition reaction, through air protection and gradient temperature reaction control, the acrylonitrile conversion rate of the addition reaction can be increased, generation of hydrogenation reaction by-products is reduced, the acrylonitrile conversion rate is larger than 99.6%, the yeild of the 3-methoxylpropylamine is larger than 99.1% and residual quantity of acrylonitrile in the crude product is smaller than 0.3%; and the hydrogenation reaction raw materials do not need to be refined, an alkaline auxiliary agent does not need to be additionally added, the average yield of MOPA can reach 96.5%, and the catalyst can be recycled for more than 30 batches.
- -
-
Paragraph 0047-0049; 0055-0056; 0058-0059; 0061-0062; ...
(2021/06/23)
-
- KOtBu-Catalyzed Michael Addition Reactions Under Mild and Solvent-Free Conditions
-
Designed transition metal complexes predominantly catalyze Michael addition reactions. Inorganic and organic base-catalyzed Michael addition reactions have been reported. However, known base-catalyzed reactions suffer from the requirement of solvents, additives, high pressure and also side-reactions. Herein, we demonstrate a mild and environmentally friendly strategy of readily available KOtBu-catalyzed Michael addition reactions. This simple inorganic base efficiently catalyzes the Michael addition of underexplored acrylonitriles, esters and amides with (oxa-, aza-, and thia-) heteroatom nucleophiles. This catalytic process proceeds under solvent-free conditions and at room temperature. Notably, this protocol offers an easy operational procedure, broad substrate scope with excellent selectivity, reaction scalability and excellent TON (>9900). Preliminary mechanistic studies revealed that the reaction follows an ionic mechanism. Formal synthesis of promazine is demonstrated using this catalytic protocol.
- Thiyagarajan, Subramanian,Krishnakumar, Varadhan,Gunanathan, Chidambaram
-
supporting information
p. 518 - 523
(2020/02/04)
-
- Preparation method of gamma-methoxypropylamine
-
The invention provides a preparation method of gamma-methoxypropylamine, which is high in conversion rate. The invention adopts the following technical scheme: the preparation method of the gamma-methoxypropylamine, comprising the following steps: preparing 3-methoxypropionitrile by using acrylonitrile and sodium methoxide as raw materials; and by taking the 3-methoxypropionitrile as a raw material, preparing the gamma-methoxypropylamine in the presence of an amine reagent, a nickel catalyst and silver nitrate in a reducing manner. The raw materials are high in utilization rate; the separationprocess is simple and clear; the energy consumption is low; the production cost of a product is low; and the solvent and the catalyst can be recycled for use.
- -
-
Paragraph 0025; 0027-0028; 0036-0037; 0045-0046; 0054-0055
(2019/03/28)
-
- Formation of a New, Strongly Basic Nitrogen Anion by Metal Oxide Modification
-
Development of new hybrid materials having unique and unprecedented catalytic properties is a challenge for chemists, and heterogeneous-homogeneous hybrid catalysts have attracted much attention because of the preferable and exceptional properties that are highly expected to result from combination of the components. Base catalysts are widely used in organic synthesis as key materials, and a new class of base catalysts has made a large impact from academic and industrial viewpoints. Here, a principle for creating a new strong base by hybridization of homogeneous and heterogeneous components is presented. It is based on the modification of organic compounds with metal oxides by using the acid-base property of metal oxides. Based on kinetic and DFT studies, combination of CeO2 and 2-cyanopyridine drastically enhanced the basicity of 2-cyanopyridine by a factor of about 109 (~9 by pKa (in CH3CN)), and the pKa was estimated to be ~21, which locates it in the superbase category. 2-Cyanopyridine and CeO2 formed a unique adsorption complex via two interaction modes: (i) coordinative interaction between the Ce atom of CeO2 and the N atom of the pyridine ring in 2-cyanopyridine, and (ii) covalent interaction between the surface O atom of CeO2 and the C atom of the CN group in 2-cyanopyridine by addition of the lattice oxygen of CeO2 to the CN group of 2-cyanopyridine. These interactions established a new, strongly basic site of N- over the CeO2 surface.
- Tamura, Masazumi,Kishi, Ryota,Nakayama, Akira,Nakagawa, Yoshinao,Hasegawa, Jun-Ya,Tomishige, Keiichi
-
supporting information
p. 11857 - 11867
(2017/09/08)
-
- Synthesis method of 3-methoxyl-N, N-dimethylacrylamide
-
The invention relates to a synthesis method of 3-methoxyl-N, N-dimethylacrylamide, and belongs to the technical field of chemical synthesis. The synthesis method comprises the following steps of adding 3-methoxypropionic acid and dimethylamine into a sealed reactor; raising the temperature to 80 to 150 DEG C; performing reaction to obtain 3-methoxyl-N, N-dimethylacrylamide, wherein the pressure in the sealed reactor is 0.1 to 10.0MPa. The 3-methoxypropionic acid is used as the raw materials to perform high-temperature dewatering with dimethylamine in a sealed reaction vessel; polyhydric alcohol and basic catalysts are not needed; the reaction is simple; the implementation is easy; the yield of a product is high; the purity is high; the high yield is realized; meanwhile, the pollution is little; the cost is low; the method conforms to the requirements of modern chemical green synthesis. Meanwhile, the 3-methoxypropionic acid uses low-price acrylonitrile as the starting raw materials; the acrylonitrile is subjected to alkoxylation to obtain methoxyl propionitrile; then, hydrolysis is performed. The operation is simple; the energy consumption is low.
- -
-
Paragraph 0039; 0042-0044
(2017/07/22)
-
- 3-methoxy-N,N-dimethylacrylamide synthesis method
-
The invention belongs to the technical field of chemical synthesis and relates to a 3-methoxy-N,N-dimethylacrylamide synthesis method. The method includes steps: adding acrylonitrile, absolute methanol and metal alkoxide into a reactor for reaction, recovering unreacted absolute methanol to obtain 3-methoxypropionitrile; adding acid catalysts and water into 3-methoxypropionitrile, heating for hydrolysis reaction, and filtering to obtain 3-methoxypropionic acid; adding 3-methoxypropionic acid and dimethylamine into a closed reactor, heating for reaction to obtain 3-methoxy-N,N-dimethylacrylamide. By adoption of cheap acrylonitrile as a starting material, the acrylonitrile is subjected to alkoxylation to obtain methoxypropionitrile which is then hydrolyzed to obtain methoxypropionic acid, and acid-base reaction, salification and dehydration are performed to obtain a target product without consumption of polyhydric alcohols and alkaline catalysts. High-temperature dehydration can be realized in the closed reactor, simplicity and feasibility in reaction are achieved, and high product yield and high purity are realized.
- -
-
Paragraph 0037; 0041; 0042
(2017/08/29)
-
- Efficient and rapid synthesis of phenolic analogs of 4-phenylbutanoic acid using microwave-assisted Michael addition as a key reaction
-
ABSTRACT: The addition of phenols to acrylonitrile in the presence of aqueous benzyltrimethylammonium hydroxide or tetramethylammonium hydroxide under microwave irradiation yielded the corresponding Michael adducts. The obtained adducts were easily transformed to phenolic analogs of 4-phenylbutanoic acids via the hydrolysis of nitrile groups.
- Iida, Hirokazu,Akatsu, Yusuke,Mizukami, Kazushi,Natori, Sho,Matsukawa, Minako,Takahashi, Kie
-
p. 581 - 585
(2016/07/06)
-
- Catalytic Olefin hydroalkoxylation by nano particles of pollucite
-
The catalytic hydroalkoxylation of α,β-unsaturated esters, nitriles, and ethers with aliphatic and aromatic alcohols over pollucite using thermal and microwave-assisted methods was investigated. To study the effect of the alcohol structures on the mechanism of the hydroalkoxylation reaction, different alcohols, such as methanol to butanol, cyclohexanol, phenol, and 2-ethylhexanol were used. The activities of pollucite, in contrast to other basic solids, were scarcely affected by the presence of air and moisture. The correlation between alcohol acidity and reaction activity is discussed. The prepared pollucite was characterized by X-ray diffraction, volumetric nitrogen adsorption surface area analysis, and CO2 temperature-programmed desorption. Scanning electron microscopy analysis revealed that the size of the modified nano catalyst particles was under 40nm.
- Zamanian, Sara,Kharat, Ali Nemati
-
p. 981 - 986
(2015/06/25)
-
- Oxa-Michael addition promoted by the aqueous sodium carbonate
-
An efficient Michael addition of alcohols to activated alkenes promoted by sodium carbonate with water as reaction medium has been developed. The reaction provides a general, economical and environmentally friendly approach for the synthesis of β-alkoxycarbonyl compounds.
- Guo, Shi-Huan,Xing, Sheng-Zhu,Mao, Shuai,Gao, Ya-Ru,Chen, Wen-Liang,Wang, Yong-Qiang
-
supporting information
p. 6718 - 6720
(2014/12/11)
-
- Cyanoethylation of alcohols and amines by cesium-modified zeolite y
-
Zeolite Y modified by cesium and magnesium ions was prepared by ion-exchange and impregnation methods, and its activity in the cyanoethylation of aliphatic and aromatic alcohols and amines was investigated. During the preparation of some samples, the transformation of zeolite Y into a pollucite-type phase occurred. This phase exhibited good activity in the cyanoethylation of aliphatic alcohols. The prepared solids modified by the impregnation method were more active than the ion-exchanged solids. The activities of the catalysts, in contrast to other basic solids, were scarcely affected by the presence of air or moisture. A correlation between catalyst basicity and catalytic activity is discussed. The catalysts were characterized by X-ray diffraction, volumetric nitrogen adsorption surface area measurement, and CO2 temperature-programmed desorption. Scanning electron microscopy revealed that the particles of the modified nanocatalysts were 40 nm. The reaction of acrylonitrile with linear alcohols in the presence of the catalysts was accelerated by microwave irradiation.
- Zamanian, Sara,Kharat, Ali Nemati
-
p. 264 - 269
(2014/03/21)
-
- An efficient and simple Morita-Baylis-Hillman reaction based on the N-methylpyrrolidine-Ba(OH)2 catalytic system
-
By using of precise catalytic amount of N-methylpyrrolidine (5 mol %) and Ba(OH)2 (1.5 mol %) in H2O/CH3OH 5/1 or CH 3OH/CH2Cl2 3/1 solvent mixtures at T=0 °C a Morita-Baylis-Hillman derivatives could be obtained in good to excellent yield from 2-cyclopenten-1-one, 2-cyclohexen-1-one and formaldehyde and diverse aryl aldehydes after suitable reaction time.
- Guerra, Krassimira P.,Afonso, Carlos A. M.
-
scheme or table
p. 2562 - 2569
(2011/04/26)
-
- Cyanoethylation of alcohols by activated Mg-Al layered double hydroxides: Influence of rehydration conditions and Mg/Al molar ratio on Broensted basicity
-
Activated Mg-Al layered double hydroxides (LDHs) with varying Mg/Al molar ratios are tested as heterogeneous catalysts for the cyanoethylation of methanol and 2-propanol. The activation procedure is performed by calcination of the LDH precursors, followed by gas-phase rehydration on an H2O/N 2 flow. In this case, rehydration is carried out at 80 °C, instead of room temperature as usual. Increased temperature has a very significant effect on the reconstruction speed, shortening the process from ~12 to 0.5 h. Good conversions and yields to alkoxypropionitriles are obtained with thus activated LDHs. Correlations are established between basic strength, as determined by CDCl3 adsorption followed by FTIR, and catalytic activity. Depending on alcohol acidity, greatest conversions are obtained over catalysts with Mg/Al molar ratios of 2 or 3. Solids are further characterized by X-ray diffraction, thermal gravimetric analyses, and 27Al MAS NMR.
- Valente, Jaime S.,Pfeiffer, Heriberto,Lima, Enrique,Prince, Julia,Flores, Jorge
-
experimental part
p. 196 - 204
(2011/05/14)
-
- Solid sodium stannate as a high-efficiency superbase catalyst for anti-Markovnikov hydroamination and hydroalkoxylation of electron-deficient olefins under mild conditions
-
A solid superbase with H- above 26.5 has been obtained through thermal treatment of sodium stannate hydrate. It was found to be an efficient catalyst for anti-Markovnikov hydroamination and hydroalkoxylation of electron-deficient olefins under mild conditions.
- Zhang, Shuguo,Wei, Yudan,Yin, Shuangfeng,Au, Chak-Tong
-
p. 712 - 716
(2013/01/09)
-
- Monomeric and dimeric nickel complexes derived from a pincer ligand featuring a secondary amine donor moiety
-
Reaction of NiBr2(CH3CN)x with the unsymmetrical pincer ligand m-(i-Pr2PO)(CH2NHBn)C 6H4 (Bn = CH2Ph) gives the complex (R,S)-κP,κC,κN-{2-(i-Pr 2PO),6-(CH2NHBn)-C6H3}Ni IIBr, 1, featuring an asymmetric secondary amine donor moiety. Deprotonation of the latter with methyl lithium gave a dark brown compound that could not be characterized directly, but fully characterized derivatives prepared from this compound indicate that it is the LiBr adduct of the 14-electron amido species [κP,κC, κN-{2-(i-Pr2PO),6-(CH2NBn)-C 6H3}Ni], 2. Thus, 2·LiBr reacts with water to regenerate 1, while reaction with excess benzyl or allyl bromide gave the POCN-type pincer complexes 3 and 4, respectively, featuring tertiary amine donor moieties. On the other hand, heating 2·LiBr at 60 °C led to loss of LiBr and dimerization to generate the orange crystalline compound [μN;κP,κC,κN- {2-(i-Pr2PO),6-(CH2NBn)-C6H3}Ni] 2, 5. Solid state structural studies show that 1, 3, and 4 are monomeric, square planar complexes involving one Ni?N interaction, whereas complex 5 is a C2-symmetric dimer involving four Ni?N interactions and a Ni2N2 core featuring a short Ni?Ni distance (2.51 A). Preliminary reactivity tests have shown that 5 is stable toward weak nucleophiles such as acetonitrile but reacts with strong nucleophiles such as CO or 2,6-Me2(C6H3)NC. Reactions with protic reagents showed that phthalimide appears to break the dimer to generate a monomeric species, whereas alcohols appear to leave the dimer intact, giving rise instead to adducts through N...H...O interactions. These ROH adducts of 5 were found to be active precatalysts for the alchoholysis of acrylonitrile with up to 2000 catalytic turnover numbers.
- Spasyuk, Denis M.,Zargarian, Davit
-
experimental part
p. 6203 - 6213
(2010/08/21)
-
- Pd(II)-catalyzed acetalization of terminal olefins with electron-withdrawing groups in supercritical carbon dioxide: selective control and mechanism
-
Pd(II)-catalyzed acetalization of terminal olefins with electron-withdrawing groups was carried out smoothly in supercritical carbon dioxide under oxygen atmosphere when polystyrene-supported benzoquinone (PS-BQ) or CuII (CuI) chloride was employed as cocatalyst. The higher selectivity was achieved, without any chlorinated by-product detected, when using PS-BQ instead of CuII (or CuI) chloride. PS-BQ could be recycled with excellent catalytic activity remaining after each simple filtration. Chlorine ion was demonstrated to be a promoter. The different acetalization mechanisms were revealed by the subtle relationship of chlorine ion and benzoquinone (BQ) to the catalytic activity of PdCl2/PS-BQ, PdII-CuCl2 or Pd(OAc)2/PS-BQ.
- Wang, Zhao-Yang,Jiang, Huan-Feng,Ouyang, Xiao-Yue,Qi, Chao-Rong,Yang, Shao-Rong
-
p. 9846 - 9854
(2007/10/03)
-
- Novel amine-catalysed hydroalkoxylation reactions of activated alkenes and alkynes
-
Substoichiometric loadings of DBU catalyse the efficient 1,4-addition of alcohols and non-nucleophilic amines such as pyrrole to activated alkenes; the application of this methodology in a one-pot synthesis of a natural product, and as a novel strategy for the synthesis of mono-protected 1,3-carbonyl compounds is reported.
- Murtagh, Julie E.,McCooey, Seamus H.,Connon, Stephen J.
-
p. 227 - 229
(2007/10/03)
-
- Chemoselective hydrogenation of α,β-unsaturated nitriles
-
The chemoselective hydrogenation of cinnamonitrile to 3-phenylallylamine proceeds with up to 80% selectivity at conversions of > 90% with Raney cobalt and up to 60% selectivity with Raney nickel catalysts. Best results were obtained with a doped Raney cobalt catalyst (RaCo/Cr/Ni/Fe 2724) in ammonia saturated methanol at 100°C and 80 bar. Major problems are the formation of hydrocinnamonitrile and of secondary amines, and overreduction to 3-phenylpropylamine. Important parameters are the catalyst type and composition, the solvent type and the presence and concentration of ammonia. The catalytic system tolerates functional groups like OH, OMe, Cl, C=O, but not aromatic nitro groups. Preliminary experiments indicate that other unsaturated nitriles with di- or trisubstituted C=C bonds are also suitable substrates.
- Kukula, Pavel,Studer, Martin,Blaser, Hans-Ulrich
-
p. 1487 - 1493
(2007/10/03)
-
- Modified Mg-Al hydrotalcite: A highly active heterogeneous base catalyst for cyanoethylation of alcohols
-
Modified Mg-Al hydrotalcite (Mg:Al = 3:1) prepared by thermal decarbonation followed by rehydration of a conventional Mg-Al hydrotalcite is found to be a highly active, reusable and air stable catalyst for cyanoethylation of alcohols.
- Kumbhar, Pramod S.,Sanchez-Valente, Jaime,Figueras, Francois
-
p. 1091 - 1092
(2007/10/03)
-
- AMIDINOETHYLATION - A NEW REACTION - IV; THE AMIDINOETHYLATION OF ALCOHOLS: A FACILE SYNTHESIS OF 3-ALKOXY-N,N'-SUBSTITUTED-PROPANAMIDINES
-
The amidinoethylation of alcohols takes place by the addition of sodium alkoxides 2 (R1=Me, Et) to the C=C double bond of a variety of N,N'-substituted-propenamidines 1 (Method A).This illustrates the activation of the C=C double bond by the conjugated amidine function and provides a new class of Michael acceptors for alcohols.However, this activation is poorer than with other nucleophiles or Michael acceptors.The amidinoethylation makes available 3-alkoxy-N,N'-substituted-amidines not easily accessible by other classical methods.However, it is demonstrated that the general N,N'-substituted-amidine synthesis via the nitrilium salts can also apply to nitrile compounds having an alkoxy group present on the molecule (method B).Since the cyanoethylation of alcohols (4) is a very fast and facile reaction the method B is the preferred strategy for the synthesis of 3-alkoxy-N,N'-substituted-propanamidines 3.
- Bril, Marc van den,Fuks, Robert
-
p. 2905 - 2908
(2007/10/02)
-