- Latent Nucleophilic Carbenes
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Using DFT and ab initio calculations, we demonstrate that noncyclic formamidines can undergo thermal rearrangement into their isomeric aminocarbenes under rather mild conditions. We synthesized the silylformamidine, for which the lowest activation energy in this process was predicted. Experimental studies proved it to serve as a very reactive nucleophilic carbene. The reactions with acetylenes, benzenes, and trifluoromethane proceeded via insertion into sp, sp2, and spCH bonds. The carbene also reacted with the functional groups, such as CHO, COR, and CN at double or triple bonds, displaying high mobility of the trimethylsilyl group. The obtained silylformamidine can be considered as a latent nucleophilic carbene. It can be prepared in bulk quantities, stored, and used when the need arises. Calculation results predict similar behavior for some other silylated formamidines and related compounds.
- Hurieva, Anastasiya,Koidan, Georgyi,Kostyuk, Aleksandr,Kyrylchuk, Andrii A.,Marchenko, Anatoliy,Rozhenko, Alexander B.,Rusanov, Eduard B.,Shvydenko, Kostiantyn
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- IMINE-TYPE QUATERNARY AMMONIUM SALT CATALYST, PREPARATION METHOD THEREOF AND USE THEREOF FOR PREPARATION OF POLYISOCYANATE COMPOSITION
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Disclosed is an imine-type quaternary ammonium salt catalyst, wherein the catalyst has a general structure formula shown by formula I below; in the formula, R1 and R2, respectively, are independently selected from a C1-C20 linear alkyl or a branched C3-C20 alkyl, and a C1-C20 hydroxylalkyl, a C3-C8 cycloalkyl, and arylated alkyl; R3 is a linear or branched alkyl, cycloalkyl or aryl; and R4 is hydrogen, aryl, a linear C1-C15 alkyl or branched C3-C15 alkyl. Also disclosed are a method for preparing the catalyst and a polyisocyanate composition prepared therefrom. The catalyst, by introducing an imine structure, on the basis of ensuring high catalytic activity thereof, is allowed to have properties of high temperature decomposition and inactivation, and when applied to the synthesis of polyisocyanate, can effectively prevent the risk of explosive polymerization caused by an uncontrolled reaction.
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Paragraph 0021; 0057-0058; 0077-0078
(2020/12/13)
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- Organic [...] compound
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This method for producing an organic silyl amine compound (3) represented by general formula (3) is characterized in that ammonia is removed by reactive distillation when an organic disilazane compound (1) represented by general formula (1) is reacted with an alkyl amine represented by general formula (2). An organic silyl amine compound can be obtained by this production method with high productivity without producing a salt. (In the formulae, each of R1, R2 and R3 independently represents a linear or branched alkyl group having 1-7 carbon atoms, a cyclic alkyl group having 3-5 carbon atoms or a phenyl group; and each of R4 and R5 independently represents a hydrogen atom, a linear or branched alkyl group having 1-5 carbon atoms or a cyclic alkyl group having 3-5 carbon atoms, provided that R4 and R5 are not hydrogen atoms at the same time.)
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Paragraph 0069; 0070; 0071; 0072; 0073; 0074; 0075-0078
(2018/05/26)
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- METHOD FOR PRODUCING DIALKYLAMINOSILANE
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In a method for synthesizing dialkylaminosilane from a reaction of dialkylamine with chlorosilane as the method for producing dialkylaminosilane, a large amount of dialkylamine hydrochloride is produced as a by-product, in addition to objective dialkylaminosilane. Therefore, upon obtaining objective dialkylaminosilane, reduction of volumetric efficiency caused by a large amount of a solvent is prevented, and dialkylaminosilane is produced at a low cost and in a large amount. Dialkylaminosilane having a small halogen content is produced with high volumetric efficiency by using, as a solvent upon allowing dialkylamine to react with chlorosilane, an aprotic polar solvent having high solubility in dialkylamine hydrochloride and metal chloride each produced as a by-product by the reaction, and straight-chain or branched hydrocarbon having high solubility in dialkylaminosilane and hard to dissolve a halogen compound therein.
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Paragraph 0044-0048
(2018/03/09)
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- An Alumino-Mannich Reaction of Organoaluminum Reagents, Silylated Amines, and Aldehydes
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A multi-component coupling using organoaluminum reagents, silylated amines, and aldehydes results in the formation of tertiary amines. Both alkenyl- and alkylaluminum reagents undergo reaction with iminium ion substrates for which the corresponding Petasis borono-Mannich reactions are unsuccessful.
- Tarasewicz, Anika,Ensan, Deeba,Batey, Robert A.
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supporting information
p. 6071 - 6074
(2018/04/27)
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- METHOD FOR PRODUCING SILYLAMINE
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PROBLEM TO BE SOLVED: To provide a method for producing a silylamine with higher efficiency and at lower cost than a conventional method. SOLUTION: There is provided a method for producing a silylamine in which R1R2R3SiNR4R5 is obtained by reacting a disilazane represented by R1R2R3SiNHSiR1R2R3 (provided that R1, R2 and R3 each independently represent an alkyl group having 1 to 3 carbon atoms or an alkenyl group having 2 to 3 carbon atoms) and an amine represented by R4R5NH (provided that R4 and R5 each independently represent an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms or a phenyl group) in the presence of a non-protonic highly polar solvent and a strong acid or an ammonium salt thereof. COPYRIGHT: (C)2015,JPOandINPIT
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Paragraph 0023; 0024; 0025; 0026
(2016/12/12)
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- Reaction of iodo(trimethyl)silane with N,N-dimethyl carboxylic acid amides
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The reactions of iodo(trimethyl)silane with N,N-dimethylformamide and N,N-dimethylacetamide Me2NCOR (R = H, Me) at a molar ratio of 1: 2 involved mainly cleavage of the N-C(=O) bond with formation of up to 80% of N,N-dimethyltrimethylsilylamine Me3SiNMe2 and the corresponding acyl iodide RCOI. In the reaction with N,N-dimethylformamide, formyl iodide HCOI was detected for the first time by gas chromatography-mass spectrometry. The contribution of Me-N bond cleavage, leading to N-methyl-N-trimethylsilyl derivative Me(Me3Si)NCOR and methyl iodide was considerably smaller. Another by-product was the corresponding N-methyl imide MeN(COR)2 formed by reaction of the initial amide with acyl iodide. The primary intermediate in the reaction of iodo(trimethyl)silane with DMF and DMA is quaternary ammonium salt [Me2(Me3Si)N +COR] I- which decomposes via dissociation of the N-CO and N-Me bonds.
- Voronkov,Tsyrendorzhieva,Lis,Rakhlin
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experimental part
p. 791 - 793
(2010/10/04)
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- A Simple and Highly Diastereoselective One-Pot Synthesis of Mannich-Bases
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A convenient one-pot procedure for the synthesis of β-amino ketones 5 from economical shelf reagents is described. Iminium salts 3 are generated in virtually quantitative yields from secondary amines 1 and aldehydes 2 mediated by NaI/Me3SiCl/NEt3. Subsequently, the salts 3 are used for the in situ aminoalkylation of enamines 4. The method provides the Mannich bases 5 in high yields and excellent diastereoselectivities (>96 % ds). It can also be applied for the aminoalkylation of other nucleophiles such as imines or electron-rich aromatic compounds.
- Arend, Michael,Risch, Nikolaus
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p. 974 - 976
(2007/10/03)
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- Tetra(amino)methanes: Implications of their structure and reactivity pattern for hypothetical carbon nitride frameworks
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Because of their possible role as model compounds for the structural units of carbon nitride C3N4, the preparation, structural chemistry, and some representative reactions of tetra(amino)methanes have been (re)investigated. In the crystal, C(NMe2)4 (1) has a molecular geometry close to D2d symmetry as proposed by theoretical calculations using state-of-the-art density functional methods. The coordination of the central carbon atom is distorted tetrahedral and the configuration of the nitrogen atoms is strongly pyramidal, as opposed to almost planar in the tetra(amino)silanes. Tetra(pyrrolidinyljmethane has a similar core structure, with all heterocyclic substituents in an envelop conformation flexible in solution. Tetra(piperidinyl)methane is more rigid in solution, owing to a more congested structure, with much higher inversion barriers for the six-membered rings. Hydrolysis of 1 leads to Me2NH and hexamethylguanidinium hydroxide, and treatment of 1 with HAuCl4(aq) affords crystalline [C(NMe2)3]+ AuCl4-, the structure of which has also been determined. Compound 1 is a strong nucleophile and can be used as an aminating agent, converting e.g. halosilanes into dimethylaminosilanes, with the guanidinium cation as the leaving group. The experimental results are discussed in the light of recent predictions regarding bulk carbon nitrides. WILEY-VCH Verlag GmbH, 1997.
- Jockisch, Alexander,Schier, Annette,Schmidbaur, Hubert
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p. 1739 - 1744
(2007/10/03)
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- DIALKYL(TRIMETHYLSILYL)TETRATHIOPHOSPHATES IN SYNTHESIS OF SUBSTITUTED TETRATHIOPHOSPHATES
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Reactions of S,S'-dialkyl-S''-trimethylsilyl tetrathiophosphates with aldehydes, acetals, ortho ethers, aminals, thioacetals, bis(thiocyanato)methane, disulfides and alkyl halides resulted in the products of tetrathiophosphate structure.Key words: S,S'-Dialkyl-S''-trimethylsilyl tetrathiophosphates; organic substances; substituted tetrathiophosphates.
- Nizamov, Il'Yas S.,Kuznetzov, Vladislav A.,Batyeva, Elvira S.
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p. 249 - 258
(2007/10/02)
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- DIALKYL TRIMETHYLSILYL TETRATHIOPHOSPHATES. SYNTHESIS AND TRANSFORMATIONS
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We have developed an efficient method for synthesizing dialkyl trimethylsilyl tetrathiophosphates, which react with aldehydes, acetals, ortho esters, thioacetals, bis(thiocyanato)methane, diethyl disulfide, and alkyl halides to give a number of new tetrathiophosphate derivatives.
- Nizamov, I.S.,Kuznetsov, V.A.,Batyeva, E.S.,Al'fonsov, V.A.
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p. 1196 - 1198
(2007/10/02)
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- Trialkylsilylating agent and process for preparing N,N-disubstituted aminotrialkylsilane using the same
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A silylating agent comprising an N-(trialkylsilyl)benzanilide having the following general formula: STR1 wherein R1 is a lower alkyl group. This agent is reacted with a secondary amine to produce an N,N-dialkylaminotrialkylsilane. This process is free of formation of amine hydrochlorides as by-products. Therefore, the problem associated with disposal of such amine hydrochlorides and the problem of limitations on the use of the silane compound product due to mixing of such amine hydrochlorides can be obviated effectively.
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- SYNTHESIS AND NMR INVESTIGATION OF PHOSPHINEIMINOPHOSPHONIUM ORGANOFLUOROPHOSPHATE SALTS
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The reaction of N-trimethylsilylphosphinineimines, Me3SiN=PR1R2R3 (R1, R2, and R3=hydrocarbon or NMe2 group) with the fluorophosphoranes, MePF4, PhPF4, and Me2PF3 has furnished fluorophosphineiminophosphonium organofluorophosphates, involving the anions, - (R=Me, Ph) or -, respectively.The characterization of these salts by 1H, 19F, and 31P n.m.r. spectroscopy is descriebed.The n.m.r. parameters are discussed in term of electronic structure.The 2JPP coupling constant was determined to be positive by triple resonance experiments on two of the compounds.
- Bartsch, Rainer,Harris, Robin K.,Norval, Elizabeth M. (nee McVicker),Stadelmann, Wilhelm,Stelzer, Othmar,Schmutzler, Reinhard
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p. 135 - 144
(2007/10/02)
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- Process for preparing polyisocyanato/polyisocyanurates by catalytic cyclotrimerization of polyisocyanates
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Polyisocyanurate/polyisocyanates of enhanced stability are prepared by partial catalytic cyclotrimerization of a polyisocyanate in the presence of a catalytically effective amount of an aminosilyl catalyst and wherein the cyclotrimerization reaction is terminated when a predetermined desired amount of isocyanurate groups has been attained, by adding to the reaction mixture, after the cooling thereof to a temperature of below 50° C., a reaction terminating amount of an organic catalyst deactivating compound comprising at least one free hydroxyl moiety, or the reaction product of such hydroxylated organic catalyst deactivating compound with an isocyanate.
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- N,N-Dimethyl(timethylsilyl)amine: Crystal and Molecular Structure at 116 K and Gas Phase Structure by Electron Diffraction
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The structure of NMe2(SiMe3) has been studied in the crystalline phase at 116 K by X-ray crystallography and in the gas phase at 295 K by electron diffraction.The solid phase structure consists of essentially isolated molecules with a Si-N bond length of 1.7194(12) Angstroem.The geometry at silicon is nearly tetrahedral and that at nitrogen is slightly non-planar, with angles CNC 111.95(12), SiNC 122.92(10) and 122.91(10) deg.The molecule possesses non-crystallographic Cs symmetry and the N-bonded methyl groups are distorted from planarity towards the unique Si-bonded methyl group, which is bent back to give an NSiC angle of 113.93(6) deg.The conformation of the Si-methyl groups is such that one CH vector of each is approximately parallel to the NSi direction; for those bonded to nitrogen, one CH bond of each lies close to the CSiN plane.In the vapour the SiNC2 skeleton was found to be planar.Principal parameters (ra) are: r(Si-N) 1.710(5), r(Si-C) 1.868(4), r(C-N) 1.462(4) Angstroem; angles SiNC 121.4(5), NSiC 110.3(7), CNC 117.1(10) deg.The molecule is distorted from Cs symmetry by a 9.6(20) deg twist of the SiMe3 group and by twists of -12.1(45) deg for each of the methyl groups on silicon.
- Blake, Alexander J.,Ebsworth, E. A. V.,Rankin, David W. H.,Robertson, Heather E.,Smith, D. Ewan,Welch, Alan J.
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- INTERACTION OF P(III) COMPOUNDS WITH SILYL HALIDES. THE MECHANISM OF THE REACTION OF PHOSPHOROUS TRIAMIDES WITH TRIALKYLSILYL HALIDES
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The reaction of phosphorous hexamethyltriamide with trimethylsilyl iodide or bromide provides a convenient synthesis of the corresponding N,N,N',N'-tetramethylphosphorodiamidous halide.Low temperature (31)P NMR studies gave evidence of the formation of a phosphonium salt-type complex with direct P-Si bonding in the first step of the reaction. Analogous phosphonium salt intermediates involving P-P bonds were found to be involved in some ligand exchange process between two tricoordinated phosphorus species.
- Cypryk, Marek,Chojnowski, Julian,Michalski, Jan
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p. 2471 - 2478
(2007/10/02)
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- 246. Monofunctional (Dimethylamino)silane as Silylating Agent
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The reaction of triorganyl(dimethylamino)silanes with surface-hydrated silicon dioxide has been studied.These silylating agents are easy to prepare from the corresponding chloro or bromosilanes with dimethylamine.The resulting products are thermally stable and relatively volatile.Reaction with surface-hydrated silicon-dioxide preparations at a50-250 deg C for 170 h yields a dense grafted layer.However, with (dimethylamino)silanes having strongly polar substituents, a retreatment of the surface-modified silica seems to be necessary in order to attain maximum coverage.
- Szabo, Katalin,Le Ha, Ngoc,Schneider, Philippe,Zeltner, Peter,sz. Kovacs, Ervin
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p. 2128 - 2142
(2007/10/02)
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- A New Method for the Preparation of Asymmetrically Substituted Phosphiniminophosphonium Salts n3P-N=PR3>X
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Tri-n-butylfluorophosphonium bromide and N-trimethylsilylphosphinimines R3P=N-SiMe3 react with formation of trimethylsilyl bromide and fluoride and mixed phosphiniminophosphonium bromides/fluorides, n3P-N=PR3>Br/F.Metathetical reactions with sodium iodide, ammonium hexafluorophosphate and potassium perchlorate yield the corresponding phosphiniminophosphonium iodides, hexafluorophosphates and perchlorates, respectively.The cations n3P-N=PR3>(+) behave as phase-transfer agents.In the presence of these cations permanganate anion is transferred from aqueous solu tions into benzene. - Key words: Silylphosphinimine; Tri-n-butylfluorophosphonium Bromide, Metathesis Reactions
- Bartsch, Rainer,Stelzer, Othmar
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p. 267 - 271
(2007/10/02)
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- 19-Hydroxy-PGI2 compounds
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Prostacyclin and prostacyclin-type derivatives having a 19-hydroxy feature are disclosed, including processes for preparing them and the appropriate intermediates. The compounds are useful for pharmacological purposes such as inhibition of blood platelate aggregation.
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- 2-Decarboxy-2-hydroxymethyl-19-hydroxy-PG1 analogs
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Prostaglandin derivatives having a 19,20-didehydro, a 19-hydroxy, or a 19-keto feature are disclosed, including processes for preparing them and the appropriate intermediates. A typical 19-hydroxy compound of this invention is 19-hydroxy-19-methyl-PGF2α, methyl ester, represented by the formula STR1
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- Bicyclic lactones
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Process for preparing bicyclic lactone acrylic aldehydes and ketones of the formula STR1 wherein "n" is one or 2, wherein R1, is hydrogen, methyl, or ethyl, and wherein R4 is hydrogen or a blocking group; and those aldehydes, ketones, and intermediates prepared therein. The aldehydes and ketones are useful intermediates in preparing prostaglandins and analogs having pharmacological utility.
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