- Reactions of Secondary Amines with Dichlorocarbene Generated in Aqueous–Alkaline Medium in the Presence of N-Methylmorpholine N-Oxide
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Dichlorocarbene generated from chloroform in aqueous–alkaline medium in the presence of N-methylmorpholine N-oxide is converted to phosgene which reacts in situ with secondary amines to afford tetrasubstituted ureas.
- Hasratyan,Bagdasaryan,Hayotsyan,Attaryan
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- A convenient synthesis of symmetrical N,N′-dialkylureas by the reactions of 4-chloro-5H-1,2,3-dithiazol-5-one with alkylamines
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Treatment of 4-chloro-5H-1,2,3-dithiazol-5-one with primary and secondary alkylamines (>2 equiv.) in CH2Cl2 at rt afforded symmetrical N,N′-disubstituted ureas in moderate to good yields. Similarly, the reactions with amino acid ester hydrochlorides in the presence of Et3N (>3 equiv.) under the same conditions gave symmetrical ureas.
- Chang, Yong-Goo,Lee, Hyi-Seung,Kim, Kyongtae
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- Design and synthesis of new immonium-type coupling reagents
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A new family of immonium-type coupling reagents is de-scribed here. The differences in the carbocation skeletons of these reagents can be correlated with differences in stability and thus reactivity. The dihydroimidazole derivatives are highly unstable to air, whereas the salts derived from dimethylamine are the most stable and the pyrrolidino derivatives are of intermediate stability. These results should be taken into account mainly when coupling reagents are deposited in open vessels, such in some automatic synthesizers. As regards both coupling yield and retention of configuration, HOAt derivatives have been confirmed to be superior to those of HOBt in all cases. For peptides containing hindered residues, fluoroformamidinium salts are more convenient than the HOAt-based reagents. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
- El-Faham, Ayman,Khattab, Sherine N.,Abdul-Ghani, Mohamed,Albericio, Fernando
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- OXALSAEUREDERIVATE DURCH OXIDATIVE KUPPLUNG VON KOHLENMONOXID AN NICKEL
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Carbon monoxide is oxidatively coupled by ligand nickel(II) compounds with secondary, primary amines and with alkali alkoxides to give oxalic acid derivatives.In the case of secondary amines the CO coupling can be run catalytically by adding oxidants like copper(II) salts.The yield of oxalic esters depends on the types of ligands and anions.
- Hoberg, Heinz,Fananas, F. Javier,Riegel, Hans Josef
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- The reaction of benzene with diethylamine in the presence of an iridium(I)/mercury(II) based system: a model route for the direct amination of aromatic hydrocarbons
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N,N-Diethylaniline is formed under mild conditions either by the direct amination of benzene with diethylamine in the presence of 5-C5Me5)(CO)2> 1 and HgSO4, or by reacting (C6H5)2Hg or C6H5HgCl/Ag2SO4 with diethylamine in the presence of 1.A preliminary investigation about the chemistry underlying these reactions is also reported.Keywords: Iridium; Amination; C-H activation; N-H activation; Mercury; Catalysis
- Diversi, Pietro,Ermini, Luca,Ingrosso, Giovanni,Lucherini, Antonio,Pinzino, Calogero,Sagramora, Laura
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- PdCl2(MeCN)2-CATALYZED CARBONYLATION OF DIETHYLAMINE WITH CARBON DIOXIDE: SELECTIVE SYNTHESIS OF TETRAETHYLUREA AND DIETHYLFORMAMIDE
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The reaction of diethylamine with carbon dioxide (CO2) with PdCl2(MeCN)2 as a catalyst gives tetraethylurea(1) or diethylformamide(2) selectively under mild reaction conditions by employing the PPh3/CCl4/MeCN and the HCOONa/methyl cellosolve systems, respectively.
- Morimoto, Yoshiaki,Fujiwara, Yuzo,Taniguchi, Hiroshi,Hori, Yuji,Nagano, Yoshiaki
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- Low-temperature synthesis of tetraalkylureas from secondary amines and carbon dioxide
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The reaction of dialkylamines with CO2 giving tetraalkylureas can be performed at 60°C. The reaction requires CCl4, is weakly promoted by DMAN or PPh3, and is not promoted by a Pd catalyst. A two-step procedure, in which dialkylammonium dialkylcarbamate is produced in situ and then reacted with CCl4 and free dialkylamine, gave greater yields of urea than a simple single-stage procedure.
- Tai, Chih-Cheng,Huck, Melissa J.,McKoon, Erin P.,Woo, Tiffany,Jessop, Philip G.
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- One-Pot Synthesis of Tertiary Amides from Organic Trichlorides through Oxygen Atom Incorporation from Air by Convergent Paired Electrolysis
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A convergent paired electrolysis catalyzed by a B12 complex for the one-pot synthesis of a tertiary amide from organic trichlorides (R-CCl3) has been developed. Various readily available organic trichlorides, such as benzotrichloride and its derivatives, chloroform, dichlorodiphenyltrichloroethane (DDT), trichloro-2,2,2-trifluoroethane (CFC-113a), and trichloroacetonitrile (CNCCl3), were converted to amides in the presence of tertiary amines through oxygen incorporation from air at room temperature. The amide formation mechanism in the paired electrolysis, which was mediated by a cobalt complex, was proposed.
- Luo, Zhongli,Imamura, Kenji,Shiota, Yoshihito,Yoshizawa, Kazunari,Hisaeda, Yoshio,Shimakoshi, Hisashi
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p. 5983 - 5990
(2021/05/04)
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- Copper(II)-catalysed oxidative carbonylation of aminols and amines in water: A direct access to oxazolidinones, ureas and carbamates
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Copper(II) chloride catalyses the oxidative carbonylation of aminols, amine and alcohols to give 2-oxazolidinones, ureas and carbamates. Reaction proceeds smoothly in water under homogeneous conditions (Ptot = 4 MPa; PO2 = 0.6 MPa, PCO), at 100°C in relatively short reaction times (4 h) and without using bases or any other additives. This methodology represents an economic and environmentally benign non-phosgene alternative for the preparation of these three important N-containing carbonyl compounds.
- Casiello, Michele,Iannone, Francesco,Cotugno, Pietro,Monopoli, Antonio,Cioffi, Nicola,Ciminale, Francesco,Trzeciak, Anna M.,Nacci, Angelo
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- Dialkylcyanamides are more reactive substrates toward metal-mediated nucleophilic addition than alkylcyanides
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The dialkylcyanamide complexes Q[PtCl3(NCNR2)] (Q = Ph3PCH2Ph, R2 = Me21, Et 22, C5H103, C4H8O 4; Q = NMe4, R2 = Me25; Q = NEt4, R 2 = Me26) were synthesized either by dissolving Q 2[Pt2(μ-Cl)2Cl4] in neat NCNR2 (1-4) or by substitution of a NCNR2 ligand with Cl- in [PtCl2(NCNR2)2] by its treatment with QCl (5, 6). Nucleophilic addition of dibenzylhydroxylamine, HON(CH2Ph)2, to 1-6 results in the formation of the complexes Q[PtCl3{NHC(NR2)ON(CH2Ph) 2}] (Q = Ph3PCH2Ph, R2 = Me 2, 7; Et2, 8; C5H10, 9; C 4H8O, 10; Q = Me4N, R2 = Me 211; Q = Et4N, R2 = Me2, 12) that further convert at room temperature in the solid state (1-24 h) or in a solution (0.5-2 h) to the imine complexes Q[PtCl3{N(CH2Ph)C(H)Ph}] (Q = Ph3PCH2Ph, 13; Me4N, 14; Et4N, 15) and the corresponding dialkylureas H2NC(O)NR2. The competitive reactivity study of the nucleophilic addition of HON(CH 2Ph)2 to (Ph3PCH2Ph)[PtCl 3(NCR′)] (R′ = Ph, NR2, CH2Ph) indicated that the reactivity of the coordinated NCNR2 is comparable to NCPh, while NCCH2Ph appeared to be much less reactive than the former two ligands. Compounds 1-6 and 13 were fully characterized by elemental analyses (C, H, N), high resolution ESI-MS, IR, and 1H and 13C{1H} NMR spectroscopy. The structure of 1 was additionally verified by a single-crystal X-ray diffraction.
- Anisimova, Tatyana B.,Bokach, Nadezhda A.,Dolgushin, Fedor M.,Kukushkin, Vadim Yu.
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p. 12460 - 12467
(2013/09/02)
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- Synthesis of urea derivatives from CO2 and amines catalyzed by polyethylene glycol supported potassium hydroxide without dehydrating agents
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Polyethylene glycol supported potassium hydroxide (KOH/PEG1000) was developed as a recyclable catalyst for facile synthesis of urea derivatives from amines and CO2 without utilization of additional dehydrating agents. Primary aliphatic amines, secondary aliphatic amines, and diamines can be converted into the corresponding urea derivatives in moderate yields. Furthermore, the catalyst can be recovered after a simple separation procedure, and reused over 5 times with retention of high activity. Georg Thieme Verlag Stuttgart.
- Kong, De-Lin,He, Liang-Nian,Wang, Jin-Quan
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supporting information; experimental part
p. 1276 - 1280
(2010/06/20)
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- Preparation of tertiary amides from carbamoyl chlorides and organocuprates
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(Chemical Equation Presented) Reaction of carbamoyl chlorides with cyano-Gilman cuprates affords tertiary amides in good to excellent yields. The reaction is general due to the possibility of using reagents made either from organolithium or from Grignard compounds. The characterization of the main side products allowed for the suggestion of a possible mechanism.
- Lemoucheux, Laurent,Seitz, Thomas,Rouden, Jacques,Lasne, Marie-Claire
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p. 3703 - 3706
(2007/10/03)
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- Process for preparation of high-purity organic compounds
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There is provided a method for obtaining a target organic compound such as an alkyladamantyl ester efficiently by purifying a crude organic compound which contains, as impurities, sublimable materials which start to sublime at temperatures lower than a boiling point of the target organic compound by use of such a simple method as distillation during its production process, without being adversely affected by adherence of the sublimable materials. The distillation is carried out in the presence of a compound having a boiling point which is lower than a boiling point of the target organic compound, e.g., a carbonyl-group-containing compound. For example, 2-methyl-2-adamantyl methacrylate (boiling point: 92° C./0.3 mmHg) containing sublimable impurities such as adamantane (sublimation starting temperature: room temperature or lower) is distilled in the presence of 1,3-dimethyl-2-imidazolidinone (boiling point: 225° C.).
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- Substituted guanidines: Introducing diversity in combinatorial chemistry
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(matrix presented) The guanidine moiety is an important motif present in many biologically active compounds. Fully substituted guanidines are of key importance for the development of bioactive molecules. The present paper reports on an efficient procedure for the direct solid-phase conversion of amines to fully substituted guanidines under very mild conditions.
- Del Fresno, Montserrat,El-Faham, Ayman,Carpino, Louis A.,Royo, Miriam,Albericio, Fernando
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p. 3539 - 3542
(2007/10/03)
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- A Willgerodt-Kindler Type Selenation of Dihalomethane Derivatives, Chloroform, and Sodium Trichloroacetate by Treating with a Base, Elemental Selenium, and an Amine
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Treatment of dihalomethane derivatives, chloroform, or sodium trichloroacetate with elemental selenium in the presence of NaH and an excess amount of an amine gave the corresponding selenoamides, selenoureas, and bis(selenocarbamoyl) triselenides in modest yields. These products were afforded from reactive intermediates related to "selenocarbonyl halides" and "selenophosgenoids" generated by the reaction of dichloromethanide ions and trichloromethanide ion with N-alkylated aminopolyselenide species (R2N-(Se)n-).
- Shimada, Kazuaki,Yamaguchi, Minoru,Sasaki, Tohru,Ohnishi, Kenji,Takikawa, Yuji
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p. 2235 - 2242
(2007/10/03)
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- Convenient Syntheses of N,N-Dialkylselenoamides and N,N,N',N'-Tetraalkylselenoureas by Treating Terminal gem-Dihaloalkanes, Chloroform , or Sodium Trichloroacetate with a Base, Elemental Selenium, and Amines
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Treatment of terminal gem-dihaloalkanes, chloroform or sodium trichloroacetate with elemental selenium in the presence of NaH and an excess amount of primary or secondary amines gave selenoamides and selenoureas in modest yields.
- Takikawa, Yuji,Yamaguchi, Minoru,Sasaki, Tohru,Ohnishi, Kenji,Shimada, Kazuaki
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p. 2105 - 2108
(2007/10/02)
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- Cobalt-catalyzed aminocarbonylation of geminal dihaloalkanes. Formation of 2-aminoamide and malonamide derivatives
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Co2(CO)8 catalyzed aminocarbonylation of geminal dihaloalkanes R2CX2 (R = H, CH3; X = Br, Cl) with NHEt2 affording R2C(NEt2)CONEt2 selectively in n-C6H14 using NEt3, while the yield of R2C(CONEt2)2 fairly increased in THF or benzene in aid of K2CO3.
- Miyashita,Kawashima,Kaji,Nomura,Nohira
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p. 781 - 784
(2007/10/02)
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- Oxidative coupling of amines and carbon monoxide catalyzed by palladium complexes. Mono- and double carbonylation reactions promoted by iodine compounds.
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Iodine is an effective promoter for the carbonylation of primary and secondary amines to ureas using palladium acetate as the catalyst and a base (e.g.K2CO3) in acetonitrile (3 h at 95 deg C and 2.7 atm).Oxamides are formed in excellent yields when secondary amines are carbonylated in the presence of iodide ion and oxygen, while primary amines give ureas as the principal product at 95 deg C, and oxamide at room temperature.
- Pri-Bar, Ilan,Alper, Howard
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p. 1544 - 1547
(2007/10/02)
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- The additivity of the thermodynamic properties of tetra-alkyl derivatives of carbamide
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The heat of combustion of tetraethylcarbamide has been determined by bomb calorimetry.The vapour pressure of liquid tetraethylcarbamide has been measured in the range 273.4-368.2 K by effusion and tensimetric methods.A triple thermal bridge has been used to measure the specific heat of tetraethylcarbamide in the range 160-370 K and its enthalpy of fusion has also been determined.The entropy of vaporisation of tetraethylcarbamide at 323.5 K was measured in a MID-200 differential microcalorimeter.The results obtained have been combined to calculate the enthalpy of formation of tetraethylcarbamide in various states of aggregation, and these values are compared with those calculated by an additive scheme.
- Kozyro, A. A.,Simirskii, V. V.,Kabo, G. Ya.,Frenkel', M. L.,Krasulin, A. P.,et al.
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p. 1274 - 1276
(2007/10/02)
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- Palladium-Catalysed Double Carbonylation of Aryl Halides To Give α-Keto Amides. Mechanistic Studies
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Various aryl halides are catalytically converted into α-keto amides and amides on treatment with secondary amines and carbon monoxide.Palladium complexes containing tertiary phosphine ligands, particularly diphenylmethylphosphine and 1,4-bis(diphenylphosphino)butane, are most effective among other transition-metal complexes.Detailed examination of factors controlling the reaction rates and selectivity for α-keto amide formation revealed the following characteristics of the reactions. (a) Reactivity of phenyl halide decreases in the order PhI > PhBr >> PhCl. (b) Oxidative addition of phenyl bromide constitutes the rate-determining step in double carbonylation of phenyl bromide, whereas in the reaction of phenyl iodide the rate determinig step is associated with the reaction of a catalitically active palladium species with carbon monoxide. (c) Introduction of an electron-withdrawing substituent into the para position of phenyl halide enhances the reactivity but decreases the selectivity for α-keto amide. (d) Employment of amines of high basicity (pKb Et2NH > piperidine > hexamethyleneimine > Me2NH > pyrrolidine probably reflects the decrease in steric bulkiness of amines. (f) Although primary amines are in general not suitable for the double carbonylation, tert-butylamine can be used because of its inertness to the product α-keto amide.Reactivity of trans-PdPh(I)(PMePh2)2 and trans-Pd(COPh)I(PMePh2)2, supposed intermediates in the catalytic reaction of PhI, toward amines and CO was examined.The relative reactivity of six secondary amines with the benzoylpalladium complex increasing in the order Pr2NH Et2NH piperidine Me2NH hexamethyleneimine pyrrolidine was found to be inversely correlated with decreasing selectivity order for α-keto amide formation in the catalytic systems.On the basis of the experimental results, a mechanism consisting of two catalytic cycles to produce α-keto amides and amides has been proposed.
- Ozawa, Fumiyuki,Soyama, Hidehiko,Yanagihara, Hisayoshi,Aoyama, Issei,Takino, Hiroaki,et al.
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p. 3235 - 3245
(2007/10/02)
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- Highly sterically hindered guanidines and process for the production thereof
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Compounds of the formula STR1 in which R1, R1 ', R2, R2 ' and R3 independently represent a C1-6 alkyl radical, in addition to which R3 may represent a hydrogen atom, the alkyl radicals together containing in all at least 8 carbon atoms, are provided for use as highly sterically hindered bases in chemical syntheses.
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