- Manganese-Pincer-Catalyzed Nitrile Hydration, α-Deuteration, and α-Deuterated Amide Formation via Metal Ligand Cooperation
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A simple and efficient system for the hydration and α-deuteration of nitriles to form amides, α-deuterated nitriles, and α-deuterated amides catalyzed by a single pincer complex of the earth-abundant manganese capable of metal-ligand cooperation is reported. The reaction is selective and tolerates a wide range of functional groups, giving the corresponding amides in moderate to good yields. Changing the solvent from tert-butanol to toluene and using D2O results in formation of α-deuterated nitriles in high selectivity. Moreover, α-deuterated amides can be obtained in one step directly from nitriles and D2O in THF. Preliminary mechanistic studies suggest the transformations contributing toward activation of the nitriles via a metal-ligand cooperative pathway, generating the manganese ketimido and enamido pincer complexes as the key intermediates for further transformations.
- Ben-David, Yehoshoa,Diskin-Posner, Yael,Kar, Sayan,Milstein, David,Zhou, Quan-Quan,Zou, You-Quan
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p. 10239 - 10245
(2021/08/24)
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- Efficient heterogeneous hydroaminocarbonylation of olefins with ammonium chloride as amino source
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An efficient protocol for heterogeneous hydroaminocarbonylation of olefins with ammonium chloride without addition of acid additive has been developed for the first time. We successfully synthesized the Pd@POPs-PPh3 catalyst through a solvothermal synthetic method. Under this heterogeneous catalytic system, C2-C6 olefins displayed good yields and TON, and a yield of 66% of propionamide and TON = 1400 were obtained under mild reaction conditions (403 K, Pethylene = 0.5 MPa, PCO = 2.5 MPa), which is a little higher than those in the homogeneous system. This catalytic system has the advantage of easy separation of product and catalyst, as well as good stability. Uniform dispersion of Pd active sites, strong coordination bond between P and Pd, high surface area, large pore volume and hierarchical porosity of Pd@POPs-PPh3 were confirmed by a series of characterizations, which is believed to be the keys for the good activity and stability of hydroaminocarbonylation reaction.
- Sun, Zhao,Yan, Li,Ji, Guangjun,Wang, Guoqing,Ma, Lei,Jiang, Miao,Li, Cunyao,Ding, Yunjie
-
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- A Molecular Iron-Based System for Divergent Bond Activation: Controlling the Reactivity of Aldehydes
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The direct synthesis of amides and nitriles from readily available aldehyde precursors provides access to functional groups of major synthetic utility. To date, most reliable catalytic methods have typically been optimized to supply one product exclusively. Herein, we describe an approach centered on an operationally simple iron-based system that, depending on the reaction conditions, selectively addresses either the C=O or C-H bond of aldehydes. This way, two divergent reaction pathways can be opened to furnish both products in high yields and selectivities under mild reaction conditions. The catalyst system takes advantage of iron's dual reactivity capable of acting as (1) a Lewis acid and (2) a nitrene transfer platform to govern the aldehyde building block. The present transformation offers a rare control over the selectivity on the basis of the iron system's ionic nature. This approach expands the repertoire of protocols for amide and nitrile synthesis and shows that fine adjustments of the catalyst system's molecular environment can supply control over bond activation processes, thus providing easy access to various products from primary building blocks.
- Chatterjee, Basujit,Jena, Soumyashree,Chugh, Vishal,Weyhermüller, Thomas,Werlé, Christophe
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p. 7176 - 7185
(2021/06/30)
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- Transamidation for the Synthesis of Primary Amides at Room Temperature
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Various primary amides have been synthesized using the transamidation of various tertiary amides under metal-free and mild reaction conditions. When (NH4)2CO3 reacts with a tertiary amide bearing an N-electron-withdrawing substituent, such as sulfonyl and diacyl, in DMSO at 25 °C, the desired primary amide product is formed in good yield with good funcctional group tolerance. In addition, N-tosylated lactam derivatives afforded their corresponding N-tosylamido alkyl amide products via a ring opening reaction.
- Chen, Jiajia,Lee, Sunwoo,Xia, Yuanzhi
-
supporting information
(2020/05/05)
-
- Hydration of nitriles using a metal-ligand cooperative ruthenium pincer catalyst
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Nitrile hydration provides access to amides that are important structural elements in organic chemistry. Here we report catalytic nitrile hydration using ruthenium catalysts based on a pincer scaffold with a dearomatized pyridine backbone. These complexes catalyze the nucleophilic addition of H2O to a wide variety of aliphatic and (hetero)aromatic nitriles in tBuOH as solvent. Reactions occur under mild conditions (room temperature) in the absence of additives. A mechanism for nitrile hydration is proposed that is initiated by metal-ligand cooperative binding of the nitrile.
- Guo, Beibei,Otten, Edwin,De Vries, Johannes G.
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p. 10647 - 10652
(2019/12/02)
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- Activation of nitriles by silver(I) N-heterocyclic carbenes: An efficient on-water synthesis of primary amides
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A first example of silver(I) N-heterocyclic carbene (Ag(I)-NHC) catalyzed on-water synthesis of primary amides by hydration of nitriles under mild reaction conditions is described. This organometallic catalytic system has excellent tolerance for various homo-aromatic, hetero-aromatic and aliphatic nitriles to afford primary amides in good yields in neat water.
- Thirukovela, Narasimha Swamy,Balaboina, Ramesh,Kankala, Shravankumar,Vadde, Ravindhar,Vasam, Chandra Sekhar
-
supporting information
p. 2637 - 2641
(2019/03/21)
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- Solvent-Tailored Pd3P0.95 nano catalyst for amide-nitrile inter-conversion, the hydration of nitriles and transfer hydrogenation of the CO bond
-
For the first time, a one pot thermolysis of [Pd(PPh3)2Cl2] prepared by reacting Ph3P with PdCl2 in a 2:1 molar ratio in MeOH at 280 °C in a trioctylphosphine (TOP) and oleylamine(OA)-octadecane(ODE) mixture (1:1) was used to prepare quantum dots (QDs; size ～2-3 nm) and nanoparticles (NPs; size ～13-14 nm), respectively, of composition Pd3P0.95. TEM, SEM-EDX, powder-XRD and XPS (for QDs only) were used to authenticate the two nanophases. 31P{1H}NMR experiments performed to monitor the progress of thermolysis reactions revealed that the phosphorus present in the Pd3P0.95 QDs had come from TOP, whereas in Pd3P0.95 NPs, its source is triphenylphosphine. The nature of the solvent did not affect the chemical composition of the nano-phase but controlled its size. Probably, solvent dependent, unique, single source precursors (SSPs) of palladium were generated in situ, and controlled the size. The catalytic activity of both Pd3P0.95 QDs and NPs was explored. The QDs were found to be efficient as a catalyst for the amide-nitrile interconversion at room temperature (yield up to 92% in 4 h), hydration of nitriles and transfer hydrogenation (TH) of carbonyl compounds with yields up to 96% in 3-4 h. The yields and reaction rates of amide-nitrile inter-conversion and TH when catalyzed by Pd3P0.95 QDs were found to be higher compared to the ones observed with the Pd/C catalyst. The binding energy of Pd(3d) in the X-ray photoelectron spectrum (XPS) of Pd3P0.95 indicated an electron transfer from the metal to phosphorus, resulting in electron deficient palladium, which facilitates the coordination of a substrate to Pd and drives the reaction. The reusability of Pd3P0.95 QDs for the interconversion was found to be up to 4-Times, while for the transfer hydrogenation of carbonyl compounds it was up to 6-Times, but with a diminished yield. Pd3P0.95 NPs were found to be less active (yield up to 36% in optimized reaction conditions) in comparison to Pd3P0.95 QDs. The mercury poisoning test suggested that the catalysis predominantly proceeded heterogeneously on the surface of the QDs. The PXRD and XPS results did not suggest a significant variation in the phase of QDs after the third catalytic cycle. The bleeding of Pd during catalysis (determined by flame AAS) and the agglomeration of QDs as supported by the SEM-EDX and TEM results are probably responsible for the reduction in the catalytic activity of QDs after reusing three times.
- Sharma, Alpesh K.,Joshi, Hemant,Bhaskar, Renu,Singh, Ajai K.
-
supporting information
p. 10962 - 10970
(2019/07/31)
-
- Directed γ-C(sp3)-H Alkylation of Carboxylic Acid Derivatives through Visible Light Photoredox Catalysis
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Visible light photoredox catalysis enables direct γ- C(sp3)-H alkylation of saturated aliphatic carbonyl compounds. Electron-deficient alkenes are used as the coupling partners in this reaction. Distinguished site selectivity is controlled by the predominant 1,5-hydrogen atom transfer of an amidyl radical generated in situ.
- Chen, Dian-Feng,Chu, John C. K.,Rovis, Tomislav
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p. 14897 - 14900
(2017/10/31)
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- Trinuclear complexes of palladium(II) with chalcogenated N-heterocyclic carbenes: Catalysis of selective nitrile-primary amide interconversion and Sonogashira coupling
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3-Methyl-1-(2-(phenylthio/seleno)ethyl)-1H-benzo[d]imidazol-3-ium iodide (L1/L2), a precursor of sulfated/selenated N-heterocyclic carbene, was synthesized by the reaction of benzimidazole with 1,2-dichloroethane followed by treatment with PhS/SeNa and MeI. The reaction of L1/L2 with Ag2O followed by treatment with [Pd(CH3CN)2Cl2] (metal to ligand ratio 3:2), i.e. transmetallation, resulted in trinuclear palladium(ii) complexes [Pd3(L1/L2-HI)2(CH3CN)Cl6] (1-2). The complexes were characterized with 1H, 13C{1H} and 77Se{1H} NMR (2 only), elemental analyses, HR-MS and single-crystal X-ray diffraction. The geometry of three Pd atoms in each complex is nearly square planar. The Pd-S/Se, Pd-C, Pd-N and Pd-Cl bond distances (?) in 1/2 are 2.3179(19)/2.4312(10), 1.968(7)/1.952(4), 2.073(8)/2.079(4) and 2.2784(19)-2.298(2)/2.292(2)-2.3003(15), respectively. In both the complexes, all Cl are trans to each other. For the central Pd atom, two benzimidazole rings are also trans to each other. The C-H?Cl non-covalent interactions result in a three-dimensional network. The moisture and air insensitive trinuclear Pd(ii) complexes 1 and 2 are thermally stable and efficient as a catalyst for nitrile-amide interconversion and amine-free Sonogashira C-C coupling (in the presence of CuI). The optimum temperature is 80 °C for the interconversion and 110 °C for the coupling. The catalytic protocols are applicable to both aliphatic and aromatic amides/nitriles. The optimum catalyst loading is 1 mol% for the C-C coupling and 0.5 to 1 mol% for the interconversion. K2CO3 as a base gives the best result for Sonogashira C-C coupling. In the conversion of nitriles to amides, the formation of an acid was not detected. After using once, 1/2 can carry out the conversion of ten fresh lots of nitriles to amides with almost the same efficiency. The real catalytic species for the interconversion and coupling appear to be based on Pd(ii) and Pd(0), respectively.
- Dubey, Pooja,Gupta, Sonu,Singh, Ajai K.
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p. 13065 - 13076
(2017/10/13)
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- Efficient Hydration of Nitriles Promoted by Gallic Acid Derived from Renewable Bioresources
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An efficient gallic acid promoted nitriles hydration at room temperature with ethanol/water as a solvent has been developed. The present protocol offers a wide range of amides in moderate to good yields. Moreover, galla chinensis extract can serve as the promoter to perform the hydration, which also shows the potential utilization of natural feedstocks.
- Deng, Tao,Wang, Cheng-Zhang
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p. 1349 - 1353
(2017/04/14)
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- A Brevibacterium process for synthesizing amide
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The invention discloses a method for synthesizing amide through nitrile hydrolysis. The method comprises the following steps: adding nitrile, acetaldoxime, water, a water-soluble rhodium complex to a reaction vessel, and cooling to room temperature after reaction of a reaction mixture for several hours at the temperature of 50-80 DEG C; and adding ethyl acetate for extraction so as to obtain an organic layer, and carrying out rotary evaporation to remove a solvent, thus obtaining a target product. Compared with a method for synthesizing amide through nitrile hydrolysis by using oxime as a water source in a transition metal catalysis process, the method has the advantages that a used catalyst is low in loading and does not contain a phosphine ligand seriously polluting environments, synthesis can be performed in air, and nitrogen protection is not needed; and therefore, the method meets the green chemistry requirements and has a wide development prospect.
- -
-
Paragraph 0081; 0082; 0083; 0084
(2017/04/29)
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- Efficient Bimetallic Catalysis of Nitrile Hydration to Amides with a Simple Pd(OAc)2/Lewis Acid Catalyst at Ambient Temperature
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Transition-metal-catalyzed nitrile hydration is an atom-economic method for the synthesis of various amides. This work demonstrates for the first time that the addition of non-redox metal ions like Sc3+ dramatically accelerate the hydration of various nitriles to amides at ambient temperature with the simple Pd(OAc)2 salt as catalyst, whereas the reactions with Pd(OAc)2 alone were very sluggish. The formation of a heterobimetallic PdII/ScIII species has been proposed as the key species for the hydration that demonstrates a bimetallic synergistic effect in this process.
- Zhang, Sicheng,Xu, Haosheng,Lou, Chenlin,Senan, Ahmed M.,Chen, Zhuqi,Yin, Guochuan
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p. 1870 - 1875
(2017/04/21)
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- Synthesis of Lactones via C-H Functionalization of Nonactivated C(sp3)-H Bonds
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An electron-deficient amide is utilized as a directing group to functionalize nonactivated C(sp3)-H bonds through radical 1,5-hydrogen abstraction. The γ-bromoamides formed are subsequently converted to γ-lactones under mild conditions. The method described is not limited to tertiary and secondary positions but also allows functionalization of primary nonactivated sp3-hybridized positions in a one-pot sequence. In addition, the broad functional group tolerance renders this method suitable for the late-stage introduction of γ-lactones into complex carbon frameworks.
- Richers, Johannes,Heilmann, Michael,Drees, Markus,Tiefenbacher, Konrad
-
supporting information
p. 6472 - 6475
(2016/12/23)
-
- Clean synthesis of primary to tertiary carboxamides by CsOH-catalyzed aminolysis of nitriles in water
-
Using CsOH as the only catalyst and utilizing its "cesium effect", a clean synthesis of a wide range of primary, secondary, and tertiary carboxamides was achieved by aminolysis reactions of nitriles with ammonia, primary, or secondary amines in water. Studies on the control reactions revealed that the reactions with ammonia most probably proceed via an aminolysis path by the initial addition of ammonia to Cs-activated nitriles to form unsubstituted amidine intermediates, while the reactions with primary or secondary amines may proceed via a hydration/transamidation path by the initial hydration of the Cs-activated nitriles to form primary carboxamide intermediates followed by their transamidation with amines through the formation of substituted amidine intermediates.
- Li, Yang,Chen, Haonan,Liu, Jianping,Wan, Xujun,Xu, Qing
-
supporting information
p. 4865 - 4870
(2016/10/06)
-
- Nitrile hydration to amide in water: Palladium-based nanoparticles vs molecular catalyst
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The catalytic performance of small Pd-nanoparticles (NPs) (2.0 nm), partially covered by chemisorbed oxygen atoms, and of Pd-acetate, both stabilized by 2,2′-bipyridine-end functionalized poly(ethyleneglycol) monomethylether was compared in the selective hydration of nitriles to amide in water under mild reaction conditions (353 K). Regardless of the nitrile substrate employed, the Pd-NP-based catalyst showed much higher normalized TON-values (i.e. refereeing to the amount of surface Pd atoms) compared to the Pd(II) macrocomplex, as far as the first catalytic run was considered. Deactivation of the Pd-NP-based catalyst was significant due to the formation of a hydroxide-water layer on the NPs' surface.
- Oberhauser,Bartoli, Mattia,Petrucci, Giorgio,Bandelli, Damiano,Frediani, Marco,Capozzoli, Laura,Cepek, Cinzia,Bhardwaj, Sunil,Rosi, Luca
-
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- One-pot synthesis of 2-alkyl-4(5)-aryl-1H-imidazoles from 1-aryl-2-bromoethanones, ammonium carbonate and aliphatic carboxylic acids
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A simple and efficient protocol for the preparation of 2-alkyl-4(5)-aryl- 1H-imidazoles starting from α-bromo aryl methyl ketones and aliphatic carboxylic acids in the presence of ammonium carbonate has been developed.
- Liu, Cong,Nie, Yijiao,Yao, Guowei,Dai, Rongji,Deng, Yulin
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p. 208 - 210
(2014/05/06)
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- Efficient and selective nitrile hydration reactions in water catalyzed by an unexpected dimethylsulfinyl anion generated in situ from CsOH and DMSO
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Unexpected dimethylsulfinyl anions (I), generated in situ from the superbase system CsOH-DMSO, was found to be a highly active catalyst for controllable nitrile hydration reactions in water, which selectively afforded the versatile amides via interesting Cs-activated I-catalyzed direct and indirect hydration mechanisms involving an O-transfer process from DMSO onto the nitriles. the Partner Organisations 2014.
- Chen, Haonan,Dai, Wujie,Chen, Yi,Xu, Qing,Chen, Jianhui,Yu, Lei,Zhao, Yajuan,Ye, Mingde,Pan, Yuanjiang
-
supporting information
p. 2136 - 2141
(2014/04/17)
-
- Magnetite nanoparticles coated with ruthenium via SePh layer as a magnetically retrievable catalyst for the selective synthesis of primary amides in an aqueous medium
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The nanostructured magnetic oxide Fe3O4 has been coated with silica and then reacted with phenylselenyl chloride under a N 2 atmosphere and RuCl3·xH2O successively in an aqueous medium to prepare Fe3O4@SiO 2@SePh@Ru(OH)x nanoparticles (NPs) for the first time. These magnetically retrievable NPs have been authenticated using TEM, SEM-EDX and powder-XRD and found to be an efficient catalyst for one pot conversion (organic solvent not required) of aldehydes, nitriles and benzyl amine to primary amides in water. For aldehydes and nitriles, the yields of primary amides are up to 93%. These NPs can be recycled more than 7 times for the conversion of benzonitrile to the corresponding amide. Gram-scale transformation carried out by using Fe3O4@SiO2@SePh@Ru(OH) x NPs as a catalyst gives ～86% yield.
- Joshi, Hemant,Sharma, Kamal Nayan,Sharma, Alpesh K.,Prakash, Om,Kumar, Arvind,Singh, Ajai Kumar
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p. 12365 - 12372
(2014/08/05)
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- Clean synthesis of amides over bifunctional catalysts of rhodium-loaded titanosilicates
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Rhodium-loaded titanosilicates were prepared and employed as efficient bifunctional catalysts in the one-pot synthesis of benzamide from benzaldehyde, hydrogen peroxide, and ammonia, which took place through a tandem reaction including ammoximation of benzaldehyde to benzaldehydeoxime and a sequential dehydration-rehydration reaction to benzamide. Various parameters that influenced the activity and product selectivity were investigated, such as crystalline topologies of the titanosilicate supports, types of transition metals, rhodium content, reaction temperature, time, solvent, and NH3/benzaldehyde molar ratio. Ti-MWW was proved to be a suitable support for loading the Rh(OH)x species. Rh(OH)x/Ti-MWWgave 84.9% of benzaldehyde conversion and 86.9% of benzamide selectivity, and it was also catalytically active for the transformation of a variety of aldehydes to the corresponding amides. The reusability of the bifunctional catalyst was also investigated. The insitu FTIR technique confirmed that the one-pot reaction included Ti-catalyzed ammoximation of benzaldehyde to the benzaldehyde oxime intermediate and sequential rhodium hydroxide related dehydration-rehydration reaction of oximes to amides.
- Xu, Le,Li, Ningning,Peng, Hong-Gen,Wu, Peng
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p. 2462 - 2470
(2013/08/23)
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- Direct catalytic formation of primary and tertiary amides from non-activated carboxylic acids, employing carbamates as amine source
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The operationally simple titanium(IV)- or zirconium(IV)-catalyzed direct amidation of non-activated carboxylic acids with ammonium carbamates generates primary, and tertiary N,N-dimethyl-substituted amides in good to excellent yields. Copyright
- Tinnis, Fredrik,Lundberg, Helena,Adolfsson, Hans
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supporting information
p. 2531 - 2536
(2012/11/06)
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- Hydration of nitriles to amides in water by SiO2-supported Ag catalysts promoted by adsorbed oxygen atoms
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A series of silica-supported silver catalysts with similar Ag loading (5 or 7 wt%) but with different preparation methods (calcination in air and reduction by H2 or NaBH4) were prepared, and their structure was characterized by microscopy (STEM), X-ray absorption fine structure (XAFS), and CO-titration of surface oxygen atom. Ag is present as metal nanoparticle with a size range of 17-30 nm. Their surface was partially covered with oxygen atoms, and the surface coverage of the oxygen depends on the preparation condition. For hydration of 2-cyanopyridine as a test reaction, turnover frequency (TOF) per surface Ag species is estimated. TOF does not show a good correlation with Ag particle size, but it linearly increases with the coverage of the surface oxygen atoms on Ag particles. The Ag/SiO2 catalyst prepared by H 2 reduction at 700 °C shows the highest TOF and it acts as effective and recyclable heterogeneous catalyst for selective hydration of various nitriles to the corresponding amides. Kinetic and Raman spectroscopic studies suggest that the surface oxygen atom adjacent to Ag0 sites plays an important role in the dissociation of H2O.
- Shimizu, Ken-Ichi,Imaiida, Naomichi,Sawabe, Kyoichi,Satsuma, Atsushi
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experimental part
p. 114 - 120
(2012/06/04)
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- Lead discovery, chemistry optimization, and biological evaluation studies of novel biamide derivatives as CB2 receptor inverse agonists and osteoclast inhibitors
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N,N′-((4-(Dimethylamino)phenyl)methylene)bis(2-phenylacetamide) was discovered by using 3D pharmacophore database searches and was biologically confirmed as a new class of CB2 inverse agonists. Subsequently, 52 derivatives were designed and synthesized through lead chemistry optimization by modifying the rings A-C and the core structure in further SAR studies. Five compounds were developed and also confirmed as CB2 inverse agonists with the highest CB2 binding affinity (CB2Ki of 22-85 nM, EC50 of 4-28 nM) and best selectivity (CB 1/CB2 of 235- to 909-fold). Furthermore, osteoclastogenesis bioassay indicated that PAM compounds showed great inhibition of osteoclast formation. Especially, compound 26 showed 72% inhibition activity even at the low concentration of 0.1 μM. The cytotoxicity assay suggested that the inhibition of PAM compounds on osteoclastogenesis did not result from its cytotoxicity. Therefore, these PAM derivatives could be used as potential leads for the development of a new type of antiosteoporosis agent.
- Yang, Peng,Myint, Kyaw-Zeyar,Tong, Qin,Feng, Rentian,Cao, Haiping,Almehizia, Abdulrahman A.,Alqarni, Mohammed Hamed,Wang, Lirong,Bartlow, Patrick,Gao, Yingdai,Gertsch, Jürg,Teramachi, Jumpei,Kurihara, Noriyoshi,Roodman, Garson David,Cheng, Tao,Xie, Xiang-Qun
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p. 9973 - 9987
(2013/01/16)
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- I2-TEMPO as an efficient oxidizing agent for the one-pot conversion of alcohol to amide using FeCl3 as the catalyst
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A high yield one-pot method for the synthesis of amides from alcohols is described. The aldehyde was generated in situ using iodine-TEMPO as oxidizing agent followed by intermediate oxime formation through reaction with NH 2OH?HCl and finally rearrangement of oxime catalyzed by FeCl3.
- Das, Rima,Chakraborty, Debashis
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experimental part
p. 48 - 53
(2012/08/28)
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- Selective conversion of aldehydes into nitriles and primary amides in aqueous media
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A simple and selective conversion of aldehydes into the corresponding nitriles and primary amides in aqueous ammonia has been developed. The aldehydes were efficiently converted to the corresponding nitriles in moderate to excellent yields using tetrabutylammonium iodide/tert-butyl hydroperoxide system. The primary amides, however, can be selectively synthesised only in the presence of tert-butyl hydroperoxide.
- Wang, Liang,Shen, Chen,Wang, Hai-Ping,Zhou, Wei-You,Sun, Fu-An,He, Ming-Yang,Chen, Qun
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p. 460 - 462
(2012/10/29)
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- Oxidation of amidoximes with IBX and IBX/TEAB
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Biologically important process of oxidation of amidoximes has been investigated using IBX (oiodoxybenzoic acid) and combination of IBX with TEAB (tetraethylammonium bromide). The reaction proceeds with high % conversion leading to selective formation of amide and nitrile depending upon the combination of reagents. ARKAT USA, Inc.
- Deshmukh, Swapnil S.,Huddar, Sameerana N.,Bhalerao, Dinesh S.,Akamanchi, Krishnacharya G.
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experimental part
p. 118 - 126
(2010/09/05)
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- Valeronitrile hydrolysis in supercritical water
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Nitriles act as important intermediates for the chemical industry and are accessible on a large scale through hydrocyanation or ammonoxidation. Nitrile hydrolysis yields amides and acids used in various applications. The conventional nitrile hydrolysis process relies on stoichiometric amounts of mineral acid or base which inherently deliver great amounts of waste brine. Improving this process towards green chemistry would require reaction conditions which can provide technically significant results without the use of catalysts. Under these conditions, the hydrolysis of valeronitrile in pure supercritical water was investigated. The experiments were performed in a continuous high pressure laboratory-scale apparatus at a temperature between 400 and 5008C, 30 MPa pressure and maximal residence time of 100 s. Nitrile conversion and valeric acid selectivity greater than 90% were achieved.
- Sarlea, Michael,Kohl, Sabine,Blickhan, Nina,Vogel, Herbert
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scheme or table
p. 85 - 90
(2011/02/25)
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- Efficient hydrolysis of nitriles to amides with hydroperoxide anion in aqueous surfactant solutions as reaction medium
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Aliphatic and aromatic nitriles are converted to corresponding amides in a single step via hydrolysis with basic H2O2 in aqueous solution of the surfactant Cetyltrimethylammonium methanesulfonate (CTAOMs). The method has several advantages: use and recycle of water as reaction medium, use of environmentally benign oxidant H2O2, easy product isolation, short reaction time, high yields and selectivity, mild conditions.
- Brinchi, Lucia,Chiavini, Lisa,Goracci, Laura,Di Profio, Pietro,Germani, Raimondo
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experimental part
p. 175 - 179
(2010/04/23)
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- Polyamide synthesis from 6-aminocapronitrile, part 1: N-alkyl amide formation by amine amidation of a hydrolyzed nitrile
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The synthesis of N-hexylpentanamide from a stoichiometric amount of pentanenitrile and hexylamine has been studied as a model reaction for the synthesis of nylon-6 from 6-aminocapronitrile. The reaction was carried out under mild hydrothermal conditions and in the presence of a homogeneous ruthenium catalyst. For the mild hydrothermal conditions the presence of hexylamine distinctively increases the nitrile hydrolysis compared to the nitrile hydrolysis in the absence of hexylamine. Amine-catalyzed nitrile hydrolysis mainly produces the N-substituted amide. A clear product development is observed, consisting of first the terminal amide formation and second the accumulation of N-hexylpentanamide. With a maximum conversion of only 80 % after 18 h, the nitrile hydrolysis rate at 230°C is still much too low for nylon-6 synthesis. Ruthenium dihydride phosphine was therefore used as a homogeneous catalyst, which significantly increases the nitrile hydrolysis rate. At a temperature of 140°C and with only 0.5 mol% [RuH2-(PPh 3)4]a 60% nitrile conversion is already reached within 2 h. Initially the terminal amide is the sole product, which is gradually converted into N-hexylpentanamide. The reaction has a high initial rate, however, for higher conversions a strong decrease in hydrolysis rate is observed. This is ascribed to product inhibition, which results from the equilibrium nature of the reaction.
- Van Dijk, Adrianus J.M.,Heyligen, Tom,Duchateau, Robbert,Meuldijk, Jan,Koning, Cor E.
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p. 7664 - 7672
(2008/03/18)
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- Polyamide synthesis from 6-aminocapronitrile, part 2: Heterogeneously catalyzed nitrile hydrolysis with consecutive amine amidation
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To test the potential of heterogeneous catalysts for the nylon-6 synthesis from 6-aminocapronitrile, a number of zeolites, aluminum silicate, and metal oxides were tested as catalysts for the model reaction of pentanenitrile with water and hexylamine to N-hexylpentanamide. All zeolitic and aluminum silicate systems showed an insufficient performance, while the metal oxides (TiO 2, ZrO2, Nb2O5) showed very promising results. The kinetic behavior of the metal oxides was further investigated. First the nitrile was catalytically hydrolyzed to the terminal amide and subsequently the amidation of the hexylamine occurred. To polymerize 6-aminocapronitrile into nylon-6, more than 99% nitrile conversion was required to obtain a high-molecular-weight polymer. Pentanenitrile conversions larger than 99% can be obtained within six hours, at 230°C, by using ZrO 2 as the catalyst. A kinetic study (by using IR spectroscopy) on the behavior of the metal oxides demonstrated that the adsorbed nitrile was catalytically hydrolyzed at the surface, but remained tightly bound to the surface. Zirconia-catalyzed polymerizations of 6-amino-capronitrile demonstrated that high-molecular-weight nylon-6 is feasible by using this route.
- Van Dijk, Adrianus J.M.,Duchateau, Robbert,Hensen, Emiel J.M.,Meuldijk, Jan,Koning, Cor E.
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p. 7673 - 7681
(2008/03/18)
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- Convenient removal of N-tert-butyl from amides with scandium triflate
-
Scandium triflate has been used as a convenient and efficient catalyst for removal of N-tert-butyl from amide groups. A variety of N-tert-butyl aryl and alkyl amides under these conditions gave the corresponding primary amide in high yields. With the use of microwave heating the deprotection reaction could be completed within 1 h.
- Mahalingam,Wu, Xiongyu,Alterman, Mathias
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p. 3051 - 3053
(2007/10/03)
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- Superoxide-mediated regioselective deblocking of the tosyl group from N-tosylcarboxamides
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In situ-generated tetraethylammonium superoxide brings about an easy and selective cleavage of the N-S bond of N-tosylcarboxamides, providing a new method for the deblocking of the tosyl group from such substrates. Copyright Taylor & Francis Group, LLC.
- Raghuvanshi,Singh
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p. 3075 - 3078
(2007/10/03)
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- Enzymatic nitrile hydrolysis catalyzed by nitrilase ZmNIT2 from maize. An unprecedented β-hydroxy functionality enhanced amide formation
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To explore the synthetic potential of nitrilase ZmNIT2 from maize, the substrate specificity of this nitrilase was studied with a diverse collection of nitriles. The nitrilase ZmNIT2 showed high activity for all the tested nitriles except benzonitrile, producing both acids and amides. For the hydrolysis of aliphatic, aromatic nitriles, phenylacetonitrile derivatives and dinitriles, carboxylic acids were the major products. Unexpectedly, amides were found to be the major products in nitrilase ZmNIT2-catalyzed hydrolysis of β-hydroxy nitriles. The hydrogen bonding between the hydroxyl group and nitrogen in the enzyme-substrate complex intermediates that disfavors the loss of ammonia and formation of acyl-enzyme intermediate, which was further hydrolyzed to acid, was proposed to be responsible for the unprecedented β-hydroxy functionality assisted high yield of amide formation.
- Mukherjee, Chandrani,Zhu, Dunming,Biehl, Edward R.,Parmar, Rajiv R.,Hua, Ling
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p. 6150 - 6154
(2007/10/03)
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- Process for the preparation of epsilon-caprolactam from a mixture comprising 6-aminocaproamide and/or oligomers
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The invention relates to a process for the preparation of ε-caprolactam from a mixture comprising 6-aminocaproamide and/or oligomers thereof, wherein in a first step 6-aminocaproamide and/or oligomers thereof is converted at a temperature of between 180 and 250°C into ammonia and 6-aminocaproic acid and/or oligomers thereof, with a separate or simultaneous removal of the ammonia, and in a subsequent step the 6-aminocaproic acid and/or oligomers thereof are converted into caprolactam at a temperature of between 250 and 400 °C.
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- A facile hydration of nitriles into amides by Al2O3/MeSO3H (AMA)
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A new and practical method for the conversion of nitriles to amides by employing the A12O3/MeSO3H (AMA) is described.
- Sharghi, Hashem,Sarvari, Mona Hosseini
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p. 207 - 212
(2007/10/03)
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- Direct conversion of aldehydes to amides, tetrazoles, and triazines in aqueous media by one-pot tandem reactions
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A variety of aldehydes reacted with iodine in ammonia water at room temperature to give the nitrile intermediates, which were trapped by addition of hydrogen peroxide, sodium azide, or dicyandiamide to produce their corresponding amides, tetrazoles, and 1,3,5-triazines in modest to high yields. The one-pot tandem reactions were conducted in water media, and the products were obtained simply by extraction or filtration.
- Shie, Jiun-Jie,Fang, Jim-Min
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p. 1158 - 1160
(2007/10/03)
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- α-and β-amino acid hydroxyethlamino sulfonamides useful as retroviral protease inhibitors
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α- and β-amino acid hydroxyethylamino sulfonamide compounds are effective as retroviral protease inhibitors, and in particular as inhibitors of HIV protease.
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- A direct synthesis of nitriles and amides from aldehydes using dry or wet alumina in solvent free conditions
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An efficient and simple procedure for the direct conversion of aldehydes into the corresponding nitriles with NH2OH·HCl/dry Al2O3/MeSO2Cl or amides with NH2OH·HCl/wet Al2O3/MeSO2Cl are studied.
- Sharghi, Hashem,Sarvari, Mona Hosseini
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p. 10323 - 10328
(2007/10/03)
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- ALPHA-KETOAMIDE DERIVATIVES
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The invention relates to α-ketoamides of the general formula wherein R 1to R 12have the significances given in the description, and their salts. The α-ketoamide derivatives provided by the present invention inhibit proteinases of viral origin, such as HCV protease, and can be used in the treatment of viral infections, especially viral infections caused by hepatitis C, hepatitis G and human GB viruses.
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- alpha - and beta -amino acid hydroxyethylamino sulfonamides useful as retroviral protease inhibitors
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alpha - and beta -amino acid hydroxyethylamino sulfonamide compounds are effective as retroviral protease inhibitors, and in particular as inhibitors of HIV protease.
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- N-acylbenzotriazoles: Neutral acylating reagents for the preparation of primary, secondary, and tertiary amides
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Readily available N-acylbenzotriazoles 2a-q efficiently acylate aqueous ammonia and primary and secondary amines to give primary, secondary, and tertiary amides in good to excellent yields. The wide applicability of the procedure is illustrated by the preparation of (i) α-hydroxyamides from α-hydroxy acids and of (ii) perfluoroalkylated amides.
- Katritzky,He,Suzuki
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p. 8210 - 8213
(2007/10/03)
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- Herbicidal glutarimides
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This invention relates to glutarimide compounds exhibiting herbicidal activity having the structure STR1 wherein A is carbonyl, thiocarbonyl or methylene, A1 is carbonyl or methylene, Q is O or (CH2)n where n is 0 or 1, D is CH or N and R, R1, R2, T, X, Y and Z are as defined within, compositions containing these compounds and methods of using these compounds as herbicides and algicides.
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- ELECTROCHEMICAL STUDIES ON HALOAMIDES. PART IX. ω-BROMO-N-TOSYLALKANAMIDES
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The electrochemical behaviour of ω-bromo-N-tosylalkanamides 1a-d at a mercury cathode in N,N-dimethylformamide solutions containing tatraethylammonium perchlorate as supporting electrode has been investigated.The cleavage of the N-S bond turns out to be selective for bromotosylvaleramide 1a and butyramide 1b giving high yields of the corresponding N-unsubstituted lactams, 2-piperidone 6a and 2-pyrrolidone 6b, irrespective of the reaction conditions.It is suggested that ring closure occurs via intramolecular nucleophilic substitution of nitrogen anions formed by dissociative electron transfer from the electrode or acid-base reaction in the bulk of the solution.Bromotosylpropanamide 1c undergoes unselective breaking of both electroactive groups C-Br and N-S and a mixture of products arising from their cleavage is formed.By way of contrast, bromotosylacetamide 1d undergoes selective cleavage of the C-Br bond giving, inter alia, its conjugate base whose stebility allowed us to further clarify the effect of added acids and bases on its voltammetric behaviour.
- Inesi, Achille,Casadei, Maria Antonietta,Moracci, Franco Micheletti,Jugelt, Werner
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- Mild hydrolysis or alcoholysis of amides. Ti(IV) catalyzed conversion of primary carboxamides to carboxylic acids or esters
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Reaction of primary amides (e.g., 1a or 6-13) or O-methylhydroxamates (1b and 1c) with a catalytic amount of TiCI4 and one equivalent of aqueous HCI converts these compounds in good yields to carboxylic esters (when an alcohol is used as solvent) or to carboxylic acids (when 9:1 dioxane:H2O is used as solvent). These conversions are chemoselective for primary amides: mono- and dialkyl amides are not affected by the reaction conditions. The hydrolysis conditions described do not compromise the stereochemical integrity of an adjacent chiral center. This is exemplified by the hydrolysis of naproxen amide (34) to naproxen (33) without detectable racemization as determined by chiral HPLC.
- Fisher,Caroon,Stabler,Lundberg,Zaidi,Sorensen,Sparacino,Muchowski
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p. 142 - 145
(2007/10/02)
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- Acyl amidine and acyl, guanidine substituted biphenyl derivatives
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Novel compounds are disclosed having the formula STR1 and wherein R1, R2 and R3 are as defined herein. These compounds inhibit the action of angiotensin II and are useful, therefore, for example, as antihypertensive agents.
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- Herbicidal glutaramic acids and derivatives
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This invention relates to glutaramic acids and derivatives exhibiting herbicidal activity having the structure STR1 wherein A is a carboxylic acid or a derivative thereof, D is CH or N, and R, R1, R2, T, X, Y, and Z are as defined within, compositions containing these compounds and methods of controlling weeds with these compounds.
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- Electrodic Cleavage of the N-S Bond in N-Tosylcarboxamides. A New Entry to N-Unsubstituted Lactams
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The electrochemical reduction of different types of N-tosylcarboxamides under various experimental conditions has been investigated.It has been found that in all instances the N-S bond is selectively cleaved with respect to the N-C bond, thus providing a new method for the deblocking of the tosyl group from such substrates.As a consequence, a two-step electrochemical synthesis for N-unsubstituted lactams is now available, which has been simplified to a one-pot procedure in the case of synthetically important azetidin-2-ones.
- Casadei, Maria Antonietta,Gessner, Andreas,Inesi, Achille,Jugelt, Werner,Moracci, Franco Micheletti
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p. 2001 - 2004
(2007/10/02)
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- Nor-statine and nor-cyclostatine polypeptides
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Polypeptides and derivatives thereof containing nor-statine and nor-cyclostatine are useful for inhibiting the angiotensinogen-cleaving action of the enzyme renin.
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- STUDY OF THE REACTIVITY OF AMMONIUM CARBOXYLATES IN THE SYNTHESIS OF AMIDES UNDER HIGH-PRESSURE DEFORMATION CONDITIONS
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On deformation under pressures up to 10 GPa the ammonium salts of aliphatic and aromatic acids, as well as mixtures of a free carboxylic acid with the ammonium salts of strong mineral acids, are converted into the corresponding amides.The amide yields increase with pressure, the magnitude of shearing deformation, and temperature.The temperature and pressure coefficients for amide formation are low and have values of 2.5-4 kJ/mole and -1 to -2 cm3/mole, respectively.The reactivity of ammonium salts in the synthesis of amides alternates in the homologous series of aliphatic acids in a similar way to the shear stress of these salts.The reactivity of the ammonium salts of aliphatic acids increases when the reaction is conducted in a matrix of an ammonium salt which possesses plasticity and a high shear stress.
- Christotina, N. P.,Zharov, A. A.
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p. 2103 - 2106
(2007/10/02)
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- Organic compounds substituted heptadeca-5,9- and 5,10-dienoic acid
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The present invention provides novel substituted heptadeca-5,9- and 5,10-dienoic acid and similar fatty acid compounds which are derivatives of certain prostaglandins and are potent thromboxane A2 inhibitors. By virtue of this pharmacological property, they represent useful pharmacological agents for a wide variety of purposes.
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