- Dihydrogen bond intermediated alcoholysis of dimethylamine-borane in nonaqueous media
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Dimethylamine-borane (DMAB) acid/base properties, its dihydrogen-bonded (DHB) complexes and proton transfer reaction in nonaqueous media were investigated both experimentally (IR, UV/vis, NMR, and X-ray) and theoretically (DFT, NBO, QTAIM, and NCI). The e
- Golub, Igor E.,Gulyaeva, Ekaterina S.,Filippov, Oleg A.,Dyadchenko, Victor P.,Belkova, Natalia V.,Epstein, Lina M.,Arkhipov, Dmitry E.,Shubina, Elena S.
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- Dehydropyrroliumsalze
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Reaction of pentachloro-2H-pyrrole with trimethylsilyldimethylamine gives azacyclopentadienylium chlorides which can be converted into inverse polarized azacyclopentadienones and 1-azafulvenes.
- Gompper, Rudolf,Junius, Martina
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Read Online
- The enthalpies of formation of bis(dimethylamino)cyanophosphine, (dimethylamino)dicyanophosphine, and tricyanophosphine
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The standard molar enthalpies of formation at the temperature 298.15 K of 2PCN(l), (CH3)2NP(CN)2(l), and P(CN)3(cr) have been determined by reaction calorimetry as -(0.4 +/- 3.2) kJ * mol-1, (189.3 +/- 5.0) kJ * mol-1, and (373.1 +/- 6.8) kJ * mol-1, respectively.Enthalpies of vaporization have been obtained from vapour-pressure measurements for the first two compounds and the corresponding values of ΔfH0m(g)/(kJ * mol-1) derived as (54.2 +/- 3.5), (228.7 +/- 5.5), and 448.4 +/- 7.4), respectively.The values of the bond enthalpies D(P-CN) in the cyanophosphines are discussed.
- Al-Maydama, H. M. A.,Finch, Arthur,Gardner, P. J.,Head, A. J.
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Read Online
- Studies in Cyclophosphazenes. Part 9. Influence of the Steric Requirements of the Amino-substituents on the Rates of Amination of 2-Amino-2,4,4,6,6-pentachlorocyclotri(λ5-phosphazenes)
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Measurements of the rates of amination of a number of aminopentachlorotriphosphazenes, N3P3Cl5(NRR') (R = n-Bu, R' = H; R = R'=n-Bu; R = i-Pr, R' = H; RR' = C5H10), with dimethylamine to give non-geminal disubstituted products have been made at two temperatures in tetrahydrofuran with the aim of elucidating the steric effects of the amino-substituents in these reactions.The values of the rate constants and of the activation parameters determined showed that steric effects are only very small.To resolve the conflict between these findings and others in literature in which appreciable steric influences were observed, the division of these amination reactions into three classes, each of which is affected by stric factors in its own way, is proposed.This enables much of the kinetic and preparative data on steric effects in these reactions to be rationalised in the framework of one general hypothesis.
- Goldschmidt, Jacob M.E.,Licht, Eliahu
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- Copper(II) complexes of tetradentate N2S2 donor sets: Synthesis, crystal structure characterization and reactivity
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Two mononuclear and one dinuclear copper(II) complexes, containing neutral tetradentate NSSN type ligands, of formulation [CuII(L1)Cl]ClO4 (1), [CuII(L2)Cl]ClO4 (2) and [CuIIsub
- Sarkar,Patra,Drew,Zangrando,Chattopadhyay
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Read Online
- Norbornane-2-spiro-α-cycloalkanone-α′-spiro-2″-norbornane-5,5″,6,6″-tetracarboxylic dianhydride, norbornane-2-spiro-α-cycloalkanone-α′-spiro-2″-norbornane-5,5″,6,6″-tetracarboxylic acid and ester thereof, method for producing norbornane-2-spiro-α-cycloalkanone-α′-spiro-2″-norbornane-5,5″,6,6″-tetracarboxylic dianhydride, polyimide obtained by using the same, and method for producing polyimide
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A norbornane-2-spiro-α-cycloalkanone-α′-spiro-2″-norbornane-5,5″,6,6″-tetracarboxylic dianhydride represented by the following general formula (1): wherein the formula (1), n represents an integer of 0 to 12, and R1s, R2, R3 each independently represents a hydrogen atom or the like.
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Page/Page column 55
(2016/10/17)
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- Stereoselective synthesis of (S)-dapoxetine: A chiral auxiliary mediated approach
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An imidazolidin-2-one chiral auxiliary mediated acetate aldol reaction was explored in the enantioselective synthesis of (S)-dapoxetine (SSRI). The diastereoselective aldol adduct was transformed to highly enantiopure (S)-dapoxetine with overall good yield.
- Khatik, Gopal L.,Sharma, Ratnesh,Kumar, Varun,Chouhan, Mangilal,Nair, Vipin A.
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p. 5991 - 5993
(2013/10/22)
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- Nucleophilic substitution reaction at the nitrogen of arylsulfonamides with phosphide anion
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A novel nucleophilic substitution reaction at the nitrogen of arylsulfonamides by means of phosphide anions has been described. This reaction allows for the efficient transformation of arylsulfonamides into synthetically valuable phosphamides, amines, and a variety of protected amines.
- Yoshida, Suguru,Igawa, Kazunobu,Tomooka, Katsuhiko
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supporting information
p. 19358 - 19361
(2013/02/22)
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- Highly chemoselective Pd-C catalytic hydrodechlorination leading to the highly efficient N-debenzylation of benzylamines
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(Equation Presented) In the presence of 1,1,2-trichloroethane, a novel procedure for the Pd-C catalytic N-debenzylation of benzylamines was established. The method proceeded in a synergistic catalytic system and directly gave the products as crystal amine hydrochlorides in practically quantitative yields.
- Cheng, Chuanjie,Sun, Jianwei,Xing, Lixin,Xu, Jimin,Wang, Xinyan,Hu, Yuefei
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supporting information; experimental part
p. 5671 - 5674
(2009/12/08)
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- Ammonia-dimethylchloramine system: Kinetic approach in an aqueous medium and comparison with the mechanism involving liquid ammonia
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After an exhaustive study of the system ammonia-dimethylchloramine in liquid ammonia, it was interesting to compare the reactivity of this system in liquid ammonia with the same system in an aqueous medium. Dimethylchloramine prepared in a pure state undergoes dehydrohalogenation in an alkaline medium: the principal products formed are N-methylmethanimine, 1,3,5- trimethylhexahydrotriazine, formaldehyde, and methylamine. The kinetics of this reaction was studied by UV, GC, and HPLC as a function of temperature, initial concentrations of sodium hydroxide, and chlorinated derivative. The reaction is of the second order and obeys an E2 mechanism (k1 =4.2 × 10-5 M-1 s-1, ΔH# = 82 kJ mol-1, ΔS# = -59 J mol-1 K-1) The oxidation of unsymmetrical dimethylhydrazine by dimethylchloramine involves two consecutive processes. The first step follows a first-order law with respect to haloamine and hydrazine, leading to the formation of an aminonitrene intermediate (k2 = 150 × 10-5 M-1 s -1). The second step corresponds to the conversion of aminonitrene into formaldehyde dimethylhydrazone at pH 13). This reaction follows a first-order law (k3 = 23.5 × 10-5 s-1) The dimethylchloramine-ammonia interaction corresponds to a SN2 bimoiecular mechanism (k4 = 0.9 × 10-5 M-1 s -1, pH 13, and T =25°C). The kinetic model formulated on the basis of the above reactions shows that the formation of the hydrazine in an aqueous medium comes under strong competition from the dehydrohalogenation of dimethylchloramine and the oxidation of the hydrazine formed by the original chlorinated derivative. A global model that explains the mechanisms both in an anhydrous and in an aqueous medium was elaborated.
- Stephan,Pasquet,Elkhatib,Goutelle,Delalu
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p. 340 - 351
(2008/09/21)
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- HIV integrase inhibitors
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The invention encompasses a series bicyclic pyrimidinone compounds of Formula I which inhibit HIV integrase and prevent viral integration into human DNA. This action makes the compounds useful for treating HIV infection and AIDS. The invention also encompasses pharmaceutical compositions and methods for treating those infected with HIV.
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(2010/11/27)
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- Nonracemic betti base as a new chiral auxiliary: Application to total syntheses of enantiopure (2S,6R)-dihydropinidine and (2S,6R)-isosolenopsins
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(Chemical Equation Presented) Total syntheses of enantiopure alkaloidal natural products (2S,6R)-dihydropinidine (as hydrochloride) and (2S,6R)-isosolenopsins (as hydrochlorides) were achieved in four steps and in 80-82% total yields by using a synthetic strategy of the formation-cleavage of 1,3-oxazinane. (S)-Betti base was proved to be an excellent chiral auxiliary and a novel Pd/C catalyzed N-debenzylation straightforward to amine hydrochloride was developed in the presence of CH2Cl2.
- Wang, Xinyan,Dong, Yanmei,Sun, Jianwei,Xu, Xuenong,Li, Rui,Hu, Yuefei
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p. 1897 - 1900
(2007/10/03)
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- High temperature-stabile silicon boron carbide nitride ceramics comprised of silylalkyl borazines,method for the production thereof, and their use
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The present invention concerns a process for producing silylalkylboranes containing the structural feature Si—C—B, new molecular silylalkylboranes, new molecular silyalkylborazines, new oligoborocarbosilazanes and polyborocarbosilazanes, a process for their production and their use as well as silicon boron carbide nitride ceramics and a process for their production.
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- Pyrazolopyrimidinone CGMP PDE5 inhibitors for the treatment of sexual dysfunction
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There is provided compounds of formula IA and of formula IB, wherein R1, R2, R3, R4and A have meanings given in the description, which are useful in the curative and prophylactic treatment of medical conditions for which inhibition of a cyclic guanosine 3′,5′-monophosphate phosphodiesterase (e.g. cGMP PDE5) is desired.
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- NOVEL SULFONYL DERIVATIVES
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Sulfonyl derivatives represented by the following general formula (I): Q1-Q2-T1-Q3-SO2-QA and drugs containing the same (wherein Q1 is an optionally substituted, saturated or unsaturated, five- or six-membered cyclic hydrocarbon group, a five- or six-membered heterocyclic group, or the like; Q2 is a single band, oxygen, sulfur, C1-C6 alkylene or the like; QA is optionally substituted arylalkenyl, heteroarylalkenyl or the like; and T1 is carbonyl or the like). These compounds have potent FXa-inhibitory effects and promptly exert satisfactory and persistent antithrombotic effects through oral administration, thus being useful as anticoagulant agents little accompanied with side effects.
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- Heterocyclic derivatives and their use as antithrombotic agents
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The present invention relates to antithrombotic compounds comprising the group Q, Q having formula (I), wherein the substructure (i) is a structure selected from (a, b and c), wherein X is O or S; X′ being independently CH or N; and m is 0, 1, 2 or 3; wherein the group Q is bound through an oxygen atom or an optionally substituted nitrogen or carbon atom, or a pharmaceutically acceptable salt thereof or a prodrug thereof. The compounds of the invention are therapeutically active and in particular are antithrombotic agents.
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- Cycloadditions of nitrile oxides to amidoximes. A general synthesis of 3,5-disubstituted 1,2,4-oxadiazole-4-oxides
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The cycloaddition of nitrile oxides to amidoximes is a general method for the synthesis of 3,5-disubstituted 1,2,4-oxadiazole-4-oxides with the same or different substituents. The yields are only moderate since an equivalent amount of the nitrile oxide is consumed by reaction with the amine released in the fragmentation of the primary cycloadducts and reforms the amidoxime. With excess nitrile oxides the 1,2,4-oxadiazole-4-oxides undergo a disproportionation reaction to yield nitroso carbonyl intermediates and 1,2,4-oxadiazoles.
- Quadrelli, Paolo,Invernizzi, Anna Gamba,Falzoni, Mario,Caramella, Pierluigi
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p. 1787 - 1796
(2007/10/03)
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- Stable, sterically-protected, bonded phase silicas prepared from bifunctional silanes
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Compositions of Formula (I): STR1 wherein R is a group selected in accordance with an intended application; R1 and R2 are protecting groups; and P is a substrate are provided. Methods of producing these compositions are also provided.
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- The enthalpies of formation of (dimethylamino)dichlorophosphine, bis(dimethylamino)chlorophosphine, and tris(dimethylamino)phosphine
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The standard molar enthalpies of formation at the temperature 298.15 K of (CH3)2NPCl2 (l), 2PCl(l), and 3P(l) have been determined by reaction calorimetry as -(286.3 +/- 2.4) kJ*mol-1, -(220.1 +/- 2.3) kJ*mol-1, and -(112.8 +/- 2.3) kJ*mol-1, respectively.Enthalpies of vaporization have been obtained from vapour-pressure measurements and the corresponding values of ΔfH0m(g) derived as -(245.5 +/- 2.5) kJ*mol-1, -(174.2 +/- 2.6) kJ*mol-1, and -(71.3 +/- 2.4) kJ*mol-1, respectively.The values of the bond enthalpies D(P-Cl) and D(P-N) in substituted phosphines are discussed.
- Al-Maydama, H. M. A.,Finch, Arthur,Gardner, P. J.,Head, A. J.
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p. 273 - 280
(2007/10/02)
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- METHOD OF TREATING DISORDERS OF THE DOPAMINERGIC SYSTEMS USING 2,5-DIAMINOTETRALINES
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The invention relates to novel 2,5-diaminotetralines of the formula: STR1 wherein R1, R2, R3 and R4 are defined herein, processes for preparing them and their use in pharmaceutical compositions. The novel 2, 5-diaminotetralines are useful in treating diseases caused by disorders of the dopaminergic systems.
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- Phosphoramidite compounds and process for production thereof
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Phosphoramidite compounds of the general formula STR1 wherein each of R1 and R2 represents a hydroxyl group having a protective group, or the group --OR4, R3 represents a hydrogen atom, a hydroxyl group having a protective group, or the group --OR4, R4 represents the group STR2 X represents a secondary amino group, R5 represents an allylic residue or a protective group capable of being split off by beta-cleavage, and BAOC represents a nucleoside base residue in which the amino or imino group is protected with an allyloxycarbonyl-type residue, with the proviso that only one of R1, R2 and R3 represents the group--OR4. The compounds can be produced by reacting a nucleoside represented by the general formula STR3 wherein each of R1 ' and R2 ' represents a hydroxyl group which may have a protective group, R3 ' represents a hydrogen atom, or a hydroxyl group which may have a protective group, and BAOC is as defined, with the proviso that only one of R1 ', R2 'and R3 ' is a hydroxyl group, with a phosphoramide compound represented by the general formula STR4 wherein X and R5 are as defined, and Y represents a secondary amino group or a halogen atom.
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- Reaktionen koordinierter Liganden V. Pentacarbonylhalogenaminophosphinkomplexe (CO)5MPRXNR'2 durch Umsetzung von (CO)5MPR(NR'2)2 mit Halogenwasserstoff
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Aminophosphines RP(NR'2)2 (R = Ph, cyclo-Hex, (-)-Men, t-Bu; R' = Me, Et) as ligands L in complexes (CO)5ML (M = Cr, Mo, W) have been found to react with HX (X = Cl, Br) mainly under substitution of only one of the two dialkylamino groups by halogen.Under similar conditions the free phosphines are converted into the dihalogenphosphines.The halogenamino complexes (CO)5MPRXNR'2 are readily accessible by this reaction, the mechanism of which is discussed.The preparation of several new compounds RP(NR'2)2 is reported.
- Diemert, K.,Kuchen, W.,Lorenzen, D.
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- α,α-DICHLOROALDEHYDES AND α,α-DICHLOROCARBOXYLIC ACIDS FROM LONG CHAIN 1-ALKANOLS. IMPROVED CHLORINATION IN THE SYSTEM DMF-CHCl3-MgCl2
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Production of α,α-dichloroaldehydes by direct chlorination of 1-alkanols with chlorine gas, catalyzed by DMF and DMF*HCl, was extended to long chain compounds (CnH2n+1OH; n = 5, 6, 8, 10, 12, 14, 16, 18).Two problems specific to the longer chains were solved to obtain isolated yields in the range 70-85 percent; a) parasitic radical chlorination was largely controlled by shielding from light; b) alkyl alkanoate side product (8 percent for n = 8 but 25 percent for n = 16 or 18) was decreased to 0-2 percent in the presence of MgCl2*H2O.Homogeneity of the reaction medium was improved with chloroform as a cosolvent.Oxidation of the aldehydes to dichlorocarboxylic acids proceeded smoothly with aqueous KMnO4 up to the tetradecanal.For the longer chains 30 percent hydrogen peroxide-NaHCO3 in acetone (overnight at 48-52 deg C) was the preferred oxidant.
- Buyck, L. De,Casaert, F.,Lepeleire, C. De,Schamp, N.
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p. 525 - 534
(2007/10/02)
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- Alkylation of cyclic and high polymeric phosphazenes via reactions between aluminum alkyls and aminophosphazenes
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(Dimethylamino)chlorophosphazenes react with (CH3)3Al, (C2H5)2AlCl, or (C2H5)3Al to replace chlorine atoms geminal to the amino groups by alkyl units. Subsequent treatment of these products with hydrogen chloride brings about replacement of the dimethylamino groups by chlorine. These reactions have been investigated for cyclic phosphazene trimers that bear one, two, or three dimethylamino units, for cyclic phosphazene tetramers that bear two or four dimethylamino units, and for a mixed-substituent high polymeric phosphazene substrate. Chlorine replacement by aluminum alkyls is promoted by the electron-supplying character of the amino side groups, and three plausible mechanisms are presented. Alkylation is accompanied by phosphorus-nitrogen bond cleavage during reactions that involve the high polymer. The new cyclophosphazenes were characterized by elemental analysis, mass spectrometry, and 31P and 1H NMR analysis. The high polymeric derivatives were also examined by gel permeation chromatography and differential scanning calorimetry.
- Allcock, Harry R.,Desorcie, James L.,Steven Rutt
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p. 612 - 619
(2008/10/08)
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- Preparation and properties of substituted (η5-divinylborane) (η5-cyclopentadienyl)cobalt complexes
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(η5-Chlorodivinylborane)(η 5-cyclopentadienyl)cobalt (1) readily undergoes the nucleophilic substitution at boron. Treatment of 1 with 2 equiv of an amine or an alcohol in the presence of base produces (η5-aminodivinylborane) (η5-cyclopentadienyl)cobalt and (η5-alkoxydivinylborane) (η5-cyclopentadienyl)cobalt complexes, respectively. Treatment of 1 with Grignard reagents gives alkyl- and aryl(η5-divinylborane)(η5-cyclopentadienyl)cobalt complexes. LiBH4 reacts with 1 to produce (η5-divinylborane)(η5-cyclopentadienyl)cobalt in high yield.
- Mintz, Eric A.
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p. 1788 - 1791
(2008/10/08)
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- REACTIONS OF N-POLYFLUOROPHENYLCARBONIMIDOYL DICHLORIDES WITH PRIMARY AND SECONDARY AMINES. KINETICS AND MECHANISM. SYNTHESIS OF POLYFLUORINATED CABODIIMIDES, CHLOROFORMAMIDINES, GUANIDINES AND BENZIMIDAZOLES
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The reactions of N-polyfluorophenylcarbonimidoyl dichlorides with primary and secondary aliphatic and aromatic amines have been studied.With primary aliphatic amines, the reactions led to carbodiimides or guanidines, depending on the amount of amine.The carbodiimides obtained reacted with amines to form guanidines.The reactions with primary aromatic amines produced only triarylguanidines.N-Pentafluorophenylcarbonimidoyl dichloride (I) reacted with tetrafluoro-o-phenylene diamine to give 2-pentafluoroanilino-4,5,6,7-tetrafluorobenzimidazole.Polyfluorinated benzimidazole derivatives were also produced by the thermolysis of polyfluorinated triarylguanidines.Heating of N1,N2,N3-tris(pentafluorophenyl)guanidine with K2CO3 in dimethylformamide led to 1,2,3,4,7,8,9,10-octafluoro-5-pentafluorophenyl-5H-benzimidazobenzimidazole.N-Polyfluorophenylcarbonimidoyl dichlorides reacted with various secondary amines alredy at room temperature giving N-polyfluorophenylchloroformamidines in high yields.Elevated temperature and prolonged reaction time led to formation of N-polyfluorophenylguanidines.Kinetics and mechanism of the reactions of N-polyfluorophenylcarbonimidoyl dichlorides with primary and secondary amines in acetonitrile at 25 deg C have been studied.The reactions have been found to proceed by a bimolecular nucleophilic addition-elimination mechanism via a tetrahedral intermediate.Possible reasons of formation of different products in the above transformations are discussed in terms of this mechanism.
- Kolesnikova, I. V.,Petrova, T. D.,Platonov, V.E.,Mikhailov, V. A.,Popov, A. A.,Savelova, V.A.
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p. 217 - 246
(2007/10/02)
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- Influence of ortho Methyl and Isopropyl Substituents on the Reactivity of N-t-Butyl P-Arylphosphonamidic Chlorides with Isopropylamine and t-Butylamine: Steric Acceleration of Metaphosphonimidate Formation by an Elimination-Addition Mechanism; Contrasting Behaviour of N,N-Dimethyl P-A...
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The two types of phosphonamidic chloride ArP(O)(Cl)NMe2, (5) and ArP(O)(Cl)NHBut (7) have been prepared with Ar=Ph, o-MeC6H4, 2,4,6-Me3C6H2, and 2,4,6-Pri3C6H2.Both types give the expected phosphonic diamide substitution products with PriNH2 and ButNH2 in MeCN, but the two types display contrasting reactivity.With ButNH2 the NMe2 substrates (5) become progressively less reactive as the degree of steric crowding increases, and although the decrease is quite small (70-fold overall) it seems consistent with an associative N2(P)> mechanism.These substrates react >=100 times faster with PriNH2, than with ButNH2 and in PriNH2-ButNH2 competitive experiments they give almost exclusively (>=99percent) the product derived from the less hindered PriNH2.For the NHBut substrates (7) with ButNH2, there is little difference in reactivity between the Ph and o-MeC6H4 compounds, and between the 2,4,6-Me3C6H2 and 2,4,6-Pri3C6H2 compounds, but remarkably the more crowded pair of substrates is the more reactive, by a factor of ca. 100.Also, in competitive experiments these substrates display relatively little preference for reaction with PriNH2.Here a dissociative elimination-addition mechanism, with a metaphosphonimidate intermediate, is seen to be important.A possible explanation of the steric acceleration is advanced.The ability of (7; Ar=Ph) to undergo substitution by elimination-addition makes possible the phosphonylation of unreactive nucleophiles such as ButOH and Pri2NH under mild conditions.
- Freeman, Sally,Harger, Martin J.
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p. 1399 - 1406
(2007/10/02)
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- Photolysis of Dimethylcarbamoyl Azide in the Presence of a Cyclic Aminimide
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Dimethylcarbamoyl azide has been photolyzed in the presence of methyl isocyanate to produce the cyclic aminimide 1,1,4-trimethyl-1,2,4-triazolidine-3,5-dione 1,2-ylide (6) and the azo compound N-(dimethylcarbamoyl)-N,N'N'-trimethylazodicarboxamide (7).The azo compound 7 arises a photolytic reaction between dimethylcarbamoyl azide and aminimide 6.Mechanistic studies support a reaction path involving intermolecular-assisted loss of nitrogen from the azide as a result of interaction with aminimide 6.
- Gibson, Harry H.,Weissinger, Keith,Abashawl, Aida,Hall, Greg,Lawshae, Tom,et al.
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p. 3858 - 3861
(2007/10/02)
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- Benzofuran derivatives and their therapeutic applications
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This invention relates to compounds having the general formula: STR1 in which STR2 is selected from: a radical STR3 in which R'1 is hydrogen and R'2 is selected from hydrogen; C1-6 alkyl; C2-6 alkenyl; C2-6 alkynyl; phenyl; phenyl C1-6 alkyl; mono-, di- and trimethoxyphenyl C1-6 alkyl; C1-6 alkoxy; benzyloxy; di-C1-6 alkylamino-C1-6 alkyl; C1-6 hydroxyalkyl; C1-6 alkyloxycarbonyl-C1-6 alkyl; a radical STR4 in which R"1 and R"2 are C1-6 alkyl; a radical STR5 in which n is selected from 4, 5 and 6; the radical STR6 and the radical STR7 and their pharmacologically acceptable inorganic and organic acid addition salts. Said compounds are therapeutically useful for the treatment of dysrhythmia.
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- PHOSPHORIC, PHOSPHONIC, AND PHOSPHINIC ACID AMIDES AS BASES
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Potentiometric titration in nitromethane, IR- and NMR-spectroscopy were used to study the processes of protonation and H-bonding for a number of phosphoric, phosphonic and phosphinic acid amides. 12N)nP(O)R23-n(R1=Me, Et; R2=EtO, Me, Et; n=1-3) including 1,3,2-dioxa-, 1,3,2-oxazaphospholane and phosphorinane derivatives>.It was shown that in these compounds the center of the highest basicity is the oxygen of the phosphoryl group.
- Matrosov, E. I.,Kryuchkov, E. E.,Nifantyev, E. E.,Kozachenko, A. G.,Kabachnik, M. I.
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- Nucleophilic Substitutions of (Z)-Perchloro-1,3-butadiene-1-carbonitrile with Sodium Phenolate and Secondary Aliphatic Amines
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The title compound 1 is threefold substituted by sodium phenolate in dioxane at 70 deg C or by sec. aliphatic amines in ether at room temperature, yielding the merocyanine-like compounds 3 or 2a - d.The structure 2 is based on UV spectroscopic investigations and degradation with hydrochloric acid to 6.Ring closure of 2 occurs under amine elimination to the 2(1H)-pyridinones 7 with sulfuric acid and to the pyridine 8a with dry hydrogen chloride.
- Roedig, Alfred,Grohe, Klaus,Sommer, Herbert
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p. 1733 - 1738
(2007/10/02)
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- Reactions of Monoprotic Thioureas with Ethyl α-Chloroacetoacetate, Ethyl Bromomalonate, and Ethyl Bromocyanoacetate
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N,N,-Dialkyl-N'-arylthioureas (1) with ethyl α-chloroacetoacetate, furnished dialkylamine hydrochlorides, aryl isothiocyanates, 2-arylimino-1,3-oxathioles (2), 2-arylimino-3-aryl Δ4-thiazolines (3), diarylthioureas (9), and carbonyl sulphide.With ethyl bromomalonate the products were dialkylamine hydrobromides, aryl isothiocyanates, 2-arylimino-3-arylthiazolidin-4-ones (11), and diarylthioureas (9).Ethyl bromocyanoacetate gave an ethyl cyanothio>acetate (13).Compound (13) with triethylamine gave the starting thiourea (1) and diethyl dicyanofumarate.
- Singh, Harjit,Ahuja, Amarjit S.,Malhotra, Nageshwar
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p. 653 - 656
(2007/10/02)
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- Studies in Cyclophosphazenes. Part 10. The Mechanism for trans-Isomer Preference in the Non-geminal Diamination of Hexachlorocyclotriphosphazene
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With the aim of elucidating the mechanistic origins of trans preference as observed in the amination reactions of chlorocyclophosphanzenes, a kinetic study of the reactions of pentachloro(dimethylamino)cyclotriphosphazene, N3P3Cl5(NMe2), with NMe2H in tetrahydrofuran produce cis-and trans-N3P3Cl4(NMe2)2 has been undertaken.Gas chromatograpic analysis was employed to follow the changes in the concentrations of the components of the product mixture with time, from which rate constants for both cis and the trans reactions at various temperatures, as well as the values of the enthalpies and the entropies of activation of both reactions, have been evaluated.The data show that the trans prefence is due solely to the fact that ΔS(exit)trans>ΔS(exit)cis.To explain the origin of trans preference the operation of modified substituent-solvating effect is postulated, according to which the substituent, after protonation, functions as a neighbouring group that by intramolecular acid catalysis facilitates departure of the chloride ion.This mechanism specifically favours the formation of the trans isomer as for steric reasons it cannot aid the formation of the cis isomer.
- Goldschmidt, Jacob M. E.,Goldstein, Rebecca
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p. 1283 - 1288
(2007/10/02)
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- Chloro(dimethylamido) compounds of tantalum(V): Preparations, properties, and structures of [Ta(NMe2)3Cl2]2, TaCl3(NMe2)2(HNMe2), Ta(NMe2)3Cl2(HNMe2), and [TaCl2(NMe2)2(HNMe2)]2O
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Ta(NMe2)5 and Me3SiCl (2 equiv) in pentane solvents react to give a microcrystalline precipitate of [TaCl2(NMe2)3]2 according to the stoichiometric reaction Ta(NMe2)5 + 2Me3SiCl → 1/2[TaCl2(NMe2)3]2 + 2Me3SiNMe2. Addition of HNMe2 to [TaCl2(NMe2)3]2 yields TaCl2(NMe2)3(HNMe2) quantitatively. From the reaction between TaCl5 and HNMe2 (5 equiv) in benzene, TaCl3(NMe2)2(HNMe2), TaCl2(NMe2)2(HNMe2), and [TaCl2(NMe2)2(HNMe2)]2O have been isolated and characterized. The first compound was originally prepared by Carnell and Fowles; the latter two compounds are new ones and are formed as minor products in the reaction. The rapid (NMR time scale) and reversible reaction between TaCl3(NMe2)2(HNMe2) and HNMe2 to give TaCl2(NMe2)3(HNMe2) and Me2NH2+Cl- has been established. All the compounds have been characterized by elemental analyses, IR spectroscopy, variable-temperature 220-MHz 1H NMR spectroscopy, and mass spectroscopy. The solid-state molecular structures of [TaCl2(NMe2)3]2, TaCl3(NMe2)2(HNMe2), and [TaCl2(NMe2)2(HNMe2)]2O have been determined by single-crystal X-ray studies. In each compound, tantalum is in a distorted octahedral environment. The Ta-NMe2 groups contain short Ta-N bond distances (1.96 ? averaged) and have planar Ta-NC2 groups indicative of extensive nitrogen p to tantalum d π bonding. The disposition of Me2N- ligands about tantalum is such that tantalum achieves the maximum effect of this π donation, viz., fac in [TaCl2(NMe2)3]2, which has a planar central Ta2(μ-Cl)2 moiety and cis in both TaCl3(NMe2)2(HNMe2) and [TaCl2(NMe2)2(HNMe2)]2O. The latter compound has a nearly linear Ta-O-Ta moiety (174°) with short Ta-O bond distances (1.92 ? averaged) indicative of oxygen p to tantalum d π bonding. The spectroscopic data are consistent with the view that TaCl2(NMe2)3(HNMe2) adopts a similar structure with a fac-Ta(NMe2)3 group. Crystal data are as follows. For [TaCl2(NMe2)3]2: space group = P21/n, a = 10.464 (3) ?, b = 13.224 (4) ?, c = 8.450 (2) ?, β = 98.07 (1)°, Z = 2, V = 1157.6 (1) ?3. For TaCl3(NMe2)2(HNMe2): space group = P21/c, a = 9.750 (3) ?, b = 10.330 (2) ?, c = 14.300 (4) ?, β = 112.05 (1)°, Z = 4, V = 1335.0 (1) ?3. For [TaCl2(NMe2)2(HNMe2)]2O: space group = P21/c, a = 8.314 (1) ?, b = 20.480 (4) ?, c = 15.778 (3) ?, β = 112.22 (1)°, Z = 4, V = 1243.5 (1) ?3.
- Chisholm, Malcolm H.,Huffman, John C.,Tan, Loon-Seng
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p. 1859 - 1866
(2008/10/08)
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- The Mechanism of Photolysis of Some Benzyltrimethylammonium Salts in Water and in Alcohols
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Photolysis of a range of benzyltrimethylammonium and 3,5-dimethoxybenzyltimethylammonium salts in water or methanol at 253.7 nm gave typically benzyl alcohols (or benzyl methyl ethers), toluenes, bibenzyls and isomers, and di- and tri-methylammonium salts.By detailed sensitisation and quenching experiments it was established that, in the photolysis of benzyltrimethylammonium bromide in aqueous t-butyl alcohol, benzyl t-butyl ether, benzyl alcohol, and some toluene were produced by a singlet pathway and bibenzyl by a triplet pathway.A general mechanistic scheme for all the photolyses studied is thus suggested.
- Appleton, David C.,Bull, David C.,Givens, Richard S.,Lillis, Veronica,Kenna, James Mc,et al.
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- Aminolysis of trifluoromethylchlorophosphoranes. Preparation and characterization of the trifluoromethyltris(dimethylamino)phosphonium ion, CF3P[N(CH3)2]3+
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The new trifluoromethyltris(dimethylamino)phosphonium ion has been prepared from CF3PCl4 or (CF3)2PCl3 and dimethylamine. The latter case involves substitution of CF3 by dimethylamine yield
- Poulin,Tomlinson,Cavell
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- Preparation of hexamethylphosphoramide
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An improved process for preparing hexamethylphosphoramide by reacting phosphorus oxychloride and dimethylamine in a liquid diluent, the improvement comprising employing hexamethylphosphoramide as the liquid diluent.
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- 2-Chloroethanephosphonic acid derivatives
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New and valuable 2-chloroethane-phosphonic acid derivatives having a strong biological action, agents for controlling the growth of plants containing these compounds as active ingredients, a process for influencing the growth of plants with these compounds, and a process for their preparation.
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- Electroless nickel- boron plating bath. Effects of variables on deposit properties
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Electroless nickel plating solutions using dimethylamine borane as the reducing agent are characterized by the unusual properties of the deposits. Nickelboron alloys up to 99. 9% nickel are obtained with proper control of a given set of plating bath conditions. The '%'pure'%' deposits have relatively low resistivity, 6 to 15 microhm- cm. The composition of the alloy remains constant over long periods of solution operation. The hardness of nickel- boron alloys deposited from solutions operated in the acid pH range lies in the range of 700 to 800 Vickers hardness number, for the as- plated deposit. The properties of the deposit are reported and discussed.
- MALLORY GO
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p. 319 - 327
(2008/10/08)
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- Low-spin binuclear titanium complexes. III. The preparation and characterization of heptachlorodititanate(VI) salts
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Treatment of bis(dimethylamino)chloroboranehexachlorodititanium(VI), [(CH3)2N]2BCl·Ti2Cl 6, with HCl affords bis(dimethylamine)dichloroboronium heptachlorodititanate(VI), {[(CH3)2/sub
- Kyker,Schram
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p. 2319 - 2327
(2008/10/08)
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- Synthesis and characterization of some perfluorophenylphosphine derivatives
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Bis(pentafluorophenyl)chlorophosphine and pentafluorophenyldichlorophosphine are prepared in good yields from pentafluorophenylmagnesium bromide and phosphorus trichloride. The reactions of the halophosphines with the Lewis bases water, ammonia, dimethylamine, and 2-methylaziridine produced substituted phosphines. Oxidative chlorination of bis(pentafluorophenyl)phosphinamide followed by dehydrohalogenation gave perfluorophenylphosphonitriles. The infrared and pertinent proton magnetic resonance spectra of these compounds are discussed.
- Magnelli,Tesi,Lowe Jr.,Mcquistion
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p. 457 - 461
(2008/10/08)
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- The chemistry of tetrakis(dimethylamino)diboron
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Tetrakis(dimethylamino)diboron reacts with certain protonic acids to give substituted diboron compounds. With hydrogen sulfide, a six-membered ring compound containing two boron-boron bonds is formed. Hydrogen cyanide, chloride, and bromide react to yield tetrasubstituted products which are stabilized by dimethylamine molecules firmly attached to the boron atoms by coordination linkages. The physical and chemical properties characterizing these compounds are given and structures are discussed.
- Malhotra
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p. 862 - 865
(2008/10/08)
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