共查询到20条相似文献,搜索用时 15 毫秒
1.
A. Paula Freitas M. Fernanda J. R. P. Proena Brian L. Booth 《Journal of heterocyclic chemistry》1995,32(2):457-462
Diazotisation of 1-acetamido-5-amino-4-cyanoimidazole 2 using sodium nitrite in aqueous acetic acid gave 5-azido-4-cyanoimidazole 3 in 94% yield. Reaction of 3 with active methylene compounds R1COCH2R2 [R1 = Me, R2 = COMe; R1 = Me, R2 = COPh; R1 = Me, R2 = COOEt] or malononitrile in the presence of base led either to imidazo[5,1-d][1,2,3,5]tetrazepines 6 and 8 or to imidazolyltriazoles 5 , 7 and 9 , depending on the reaction conditions. Tetrazepine 6c evolves to triazole 7c or 5c respectively in the presence of acid or by further treatment with base. Purine 10 was also isolated in the reaction of 3 with malononitrile. 相似文献
2.
Yoshihisa Kurasawa Tomoyoshi Hosaka Atsushi Takada Ho Sik Kim Yoshihisa Okamoto 《Journal of heterocyclic chemistry》1995,32(2):531-535
The 3-(arylhydrazono)methyl-2-oxo-1,2-dihydroquinoxalines 1a-h and 2a-e showed tautomeric equilibria between the hydrazone imine A and diazenyl enamine B forms in a series of mixed trifluoroacetic acid/dimethyl sulfoxide media. The substituent and solvent effects on the tautomer ratios of A to B in a series of mixed media were studied for compounds 1a-h and 2a-e by the nmr spectroscopy. In compounds 1a-h and 2a-e , the ratios of the tautomer B gradually increased with elevation of acid concentration, and the tautomer B exclusively existed in trifluoroacetic acid media. The various acid concentrations (C v/v%, C' mol/1) giving the 1:1 tautomer ratios [C(A:B = 1:1), C'(A:B = 1:1)] were obtained from all compounds (Figures 1–13), and the linear correlation of the Hammett σp values with the log C'(A:B = 1:1) values were observed for compounds 1a-h. The larger Hammett σp values brought about the larger acid concentrations C(A:B = 1:1) in compounds 1a-h and 2a-e , indicating that the higher acid concentration was required for the stabilization of tautomer B possessing the electron-withdrawing p-substituents R1, which weakened the basicity of the azo nitrogen atom. Moreover, the ester group R2 of compounds 2a-e was found to decrease the electron density of the azo nitrogen atom, since the acid concentration C(A:B = 1:1) of compound 2c (R1 = H, R2 = COOMe, σp = O) was 52%, whose value was larger than that of compound 1b (R1 = CN, R2 = H, σp = 0.66) [C(A:B = 1:1) = 42%]. 相似文献
3.
Aroop K. Roy Urszula G. Wettermark Gary M. Scheide Patty Wisian-neilson Robert H. Neilson 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3-4):147-153
Abstract The reactions of a variety of electrophiles with the N-silyl-P-trifluoroethoxyphosphoranimine anion Me3Sin°P(Me)(OCH2CF3)CH? 2 (1a), prepared by the deprotonation of the dimethyl precursor Me3SiN[dbnd]P(OCH2CF3)Me2 (1) with n-BuLi in Et2O at-78°C, were studied. Thus, treatment of 1a with alkyl halides, ethyl chloroformate, or bromine afforded the new N-silylphosphoranimine derivatives Me3SiN[dbnd]P(Me)(OCH2CF3)CH2R [2: R = Me, 3: R = CH2Ph, 4: R = CH[sbnd]CH2, 5: R = C(O)OEt, and 6: R = Br]. In another series, when 1a was allowed to react with various carbonyl compounds, 1,2-addition of the anion to the carbonyl group was observed. Quenching with Me3SiCl gave the O-silylated products Me3SiN[dbnd]P(Me)(OCH2CF3)CH2°C(OSiMe3)R1R2 [7: R 1 = R 2 = Me; 8: R 1 = Me, R 2 = Ph; 9: R1 = Me, R 2 = CH[sbnd]CH2; and 10: R 1 = H, R 2 = Ph]. Compounds 2–10 were obtained as distillable, thermally stable liquids and were characterized by NMR spectroscopy (1H, 13C, and 31P) and elemental analysis. 相似文献
4.
《合成通讯》2013,43(6):785-790
Abstract The effect of microwave irradiation on the condensation reactions of arylaldehydes 1 and active methylene compounds 2 in aqueous media was studied and compared with “classical” conditions. The results show that the condensation was carried out only under microwave irradiation in the presence of ammonium chloride as a catalyst, followed by dehydration, to afford (E)‐olefins 3. The protocol was used to synthesize coumarins by a condensation reaction of salicylaldehyde or its derivatives with various derivatives of ethylacetate 5 (e.g., R3CH2CO2Et; R3: CO2Et, CO2Me, COMe, CN) in high yields. These investigations will contribute to the development of environmentally friendly and inexpensive processes in organic synthesis. 相似文献
5.
A strong deshielding effect is observed for the carbon signal of carbocation center (C+) in the 13C NMR spectra of coordinated propargyl cations [Cp2Mo2(CO)4(μ-η2,η3-(HC≡CCR1R2)]+ BF4− (R1 = R2 = H) 1, (R1 = Me, R2 = H) 2, and (R1 = R2 = Me) 3 when hydrogen is replaced by methyl; the effect increases with the Mo-C+ distance (75.37, 98.3, and 148.68 ppm for compounds 1, 2, and 3, respectively). This indicates that the back-donation of electron density from the metal onto the ligand makes a substantial
contribution to the stabilization of these cations.
Original Russian Text ? I.V. Barinov, V.A. Chertkov, 2009, published in Vestnik Moskovskogo Universiteta. Khimiya, 2009, No.
1, pp. 29–34. 相似文献
6.
Huiling Wang Yang Huazheng Wu Ye 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract O-Ethyl-N-alkylphosphoro(thioureido)thioates(II) were synthesized by the addition of O-ethyl-N-alkylphosphor-isothiocyanatidothioates(I) with corresponding alkyl or aryl amines, in which R=C1, -C3, R1, R2=H, alkyl or aryl. Their structures were confirmed by IR, 1H NMR, MS and elemental analysis. The results of bioassay showed that they had fairly good fungicidal and herbicidal activities. When II(R1=H,R2=i-Pr,Ph,aryl etc.) reacted with chloroacetyl chloride, the compounds III were given. 相似文献
7.
Zhanneta R. Gulyaeva Igor I. Patsanovsky Elenora A. Ishmaeva K. Micheal Pietrusiewicz 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract A series of derivatives R1R2P(X)R3, where R1=R2=Ph. R3= -CH=CH-Me, X=O(I); R1=Me, R2=Ph, R3= -CH=CH2, X=O(II); R1=R2=Ph, R3= -CH=CH2, X=Se(III) and R1R2P(O)-CH2C(O)OX, where R1=Ph, R2= -CH=CH2, X=Ment?(IV); R1=Ph-2-OMe, R2=Ph, X=Ment?(V); R1=R2=CH2Ph, X=Et(I), were investigated by means of dipole moments method. The problem of conjugation in phosphorylethylenes and conformation behaviour of phosphorylacetates was considered. DM (exp.) of (I-IV), determined in CC14 solution are 4.48(I), 4.27(II), 4.97(III), 4.21(IV), 5.21(V) and 4.02 D (VI). The intramolecular electronic interactions of phosphoryl group with unsaturated fragment did not displays in polarity properties of compounds (I-III). The experimental dipole moments of derivatives (I-III) are equal to the calculated values of DM. DM (IV-VI) is very sensitive to orientation of the P=O and C=O polar bonds. Because DM (exp.) of these compounds very sensitive to its orientation. DM (calc.) for cis- and trans- orientation of P=O and C=O dipoles are really different, that allows to drow the conclution that, in the contrast to the crystal state, the corresponded dipoles prefer an anti array in solution. 相似文献
8.
《Tetrahedron》1986,42(8):2243-2252
Thiocyanic acid HSCN is added to some acetylenic compounds R1-C&2 through a two-step one-pot procedure wich involves, first, the generation in CH2Cl2 of β-thiocyanato and/or β-isothiocyanato alkenyl mercuric coupounds R1-C (SCN)=CR2-Hg- by addition of mercury (II) thiocyanate Hg(SCN)2 to R1-C&2 then the substitution of mercury by hydrogen through acidic treatment. In proper conditions of stoechiometry and reaction time the process is tharmodynamically controlled and thus allows to obtain vinyl isothiocyanates R1-C(-NCS)CHR2 even when the isomeric vinyl thiocyanates are kinetically favoured. Preparation of 3,3- dimethyl 2-isothiocyanato 1-thiocyanato 1-butene is also reported. 相似文献
9.
Kolomnikova G. D. Petrovskii P. V. Sorokin P. V. Dolgushin F. M. Yanovsky A. I. Chizhevsky I. T. 《Russian Chemical Bulletin》2001,50(4):706-715
The reaction of OsCl2(PPh3)3 with [nido-7-R1-8-R2-C2B9H10]K+ produced a series of new exo-nido-osmacarborane complexes exo-nido-5,6,10-[Cl(Ph3P)2Os]-5,6,10-(-H)3-10-H-7-R1-8-R2-7,8-C2B9H6 (1: R1 = R2 = H; 2: R1 = R2 = Me; 3: R1 = R2 = PhCH2; 4: R1 + R2 = 1,2-C6H4(CH2)2; 5: R1 = H, R2 = Me) in which the osmium-containing group is linked to the nido-carborane ligand through three two-electron three-center bonds. Compounds 1—5 are formed as mixtures of symmetric (a) and asymmetric (b) isomers; pure symmetric isomers 2a and 4a were isolated by fractional crystallization, and the mixture of isomers 3a, was quantitatively separated into individual compounds 3a and 3b by column chromatography on silica gel. Detailed analysis of the 31P{1H}, 1H, 11B NMR spectra of 1a,b—5a,b and 2D 1H-1H{11B} and 11B{1H}-11B{1H} NMR spectra of 3a and 3b was performed. The structures of isomers 2a and 4a were confirmed by an X-ray diffraction study. According to the NMR and X-ray diffraction data, the isomerism of exo-nido-complexes 1a,b—5a,b is actually the cis—trans-isomerism of ligand arrangement in the octahedral coordination of the Os atom. 相似文献
10.
Dmitry V. Moiseev Brian R. James Aleksey V. Gushchin 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6):678-690
Abstract Phosphonium zwitterions of the known type R3P+CH(Ar)CH2CO2 ? (II) are obtained as a racemic mixture in moderate yield via a 1:1 reaction of cinnamic acids (Ar = phenyl, or substituted phenyl) with [HO(CH2)3]3P in acetone at room temperature under Ar. The products are characterized by elemental analysis, 31P{1H}-, 1H-, and 13C{1H}-NMR spectroscopies, and mass spectrometry, although they contain a minor coproduct formed via neutralization of the positive and negative charges of II with the respective acid and phosphine reactants (see Experimental Section). In CD3OD, the monodeuterated salts R3P+CH(Ar)CH(D)CO2 ? are formed as a mixture of diastereomers with d.r. values of ~2 to 8, depending on substituent groups present in the organic acid; in these studies, 2-HO-cinnamic acid is the most reactive, and β-methylcinnamic acid is the least reactive. 相似文献
11.
I. V. Borisova N. N. Zemlyanskii A. K. Shestakova V. N. Khrustalev Yu. A. Ustynyuk e. A. Chernyshev 《Russian Chemical Bulletin》2000,49(9):1583-1592
Photolysis and thermal decomposition of betaines R3P−CR1R2−SiR3R4−S− (1) follows two main pathways: (a) a Corey—Chaykovsky type reaction with elimination of Ph3P and generation of silathiirane
(2) and (b) a retro-Wittig type reaction accompanied by elimination of R3P=CR1R2 and generation of silanethione R3R4Si=S (3). Highly reactive compounds2 and3 undergo subsequent transformations to give derivatives of tetrahydro-1,4-dithia-2,5-disilin, 1,3-dithia-2,4-disilolane, and
phosphonium salts ofsymm-tetraorganodisilthiane dithiolates [Ph3P+CHR1R2]2[(R3R4SiS−)2S]. The structures of the compounds obtained were established by X-ray diffraction analysis and multinuclear NMR spectroscopy.
For part 3, see Ref. 1.
The betaines Et3P+CHMeSiMe2S− and Et3P+CHMeSiPh2S− with alkyl groups at the phosphorus atom are distinguished by high thermal stability; their spectral characteristics do not
change during storage of solutions of these compounds in pyridine-d5 or metastable solutions in benzene-d6 for 1–2 years at −20°C in sealed evacuated tubes or on heating (150°C) for 15 h.
Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1594–1603, September, 2000. 相似文献
12.
A systematic study of the mesomorphic properties of three series of copper(II) complexes based on β-diketonate ligands containing branched side chains is reported. These disc-like compounds have four, six and eight flexible alkoxy side chains appended to the central core, in which two or four side chains were substituted by bulkier secondary alkoxy groups: 1-methylbutyloxy R ' = C5(2°) or 1-methylheptyloxy R ' = C8(2°). The mesomorphic results indicated that at least eight side chains are required to form stable columnar mesophases; other compounds with four or six side chains are not mesogenic regardless of the combination of the carbon length on the alkoxy or secondary alkoxy groups of the side chains. The compounds 3 with shorter R ' = C5(2°) side chains were all non-mesogenic regardless of the carbon length of three alkoxy side chains (R = C8, C10, C12) used. However, when the longer 1-methylheptyloxy side chain R ' = C8(2°) was substituted, the compounds 3b-3e with various alkoxy groups (R = C6, C7, C8, C10, C12) exhibited columnar phases. The mesophases were characterized and identified as columnar hexagonal phases (Colh), as expected, by thermal analysis and optical polarized microscopy. The presence of the introduced secondary alkoxy groups apparently appeared to influence the formation of columnar phases. The clearing points were relatively lower than other similar copper(II) compounds not substituted by secondary alkoxy side chains. 相似文献
13.
H. Vogt V. Kolleck L. Riesel 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract Carbonyl compounds react with CBr2F2 in the presence of phosphanes, RP (R = Ph, NR;), and metals (M = Zn, Cd, Pb) forming geminal difluoroolefins (eq. 1)1. R′CHO + CBr2F2 + R3P + M → R′CH=CF2 + MBr2 + R3PO (1) Without any doubt this reaction has to occur via the intermediate formation of difluoromethylene phosphoranes, which then undergo the Wittig reaction with carbonyl compounds (eq. 2). R3P=CF2 + R′CHO → R3PO + R′CH=CF2 (2). 相似文献
14.
Novel copolymerization of ethylene with substituted allenes(CH2=C = CH—R,1:R = n-butyl,2:R =n-octyl) using bis(β-enaminoketonato)titanium catalysts[PhN = C(R2)CHC(R1)O]2TiCl2(1a:R1 = CF3,R2 = CH3;1b:R1 = Ph,R2 = CF3) has been investigated.In the presence of modified methylaluminoxane,these catalysts can copolymerize ethylene with substituted allenes,affording copolymers with unimodal molecular weight distributions and homogeneous compositions.By varying the reaction conditions,the comonomer incorporation can be tuned in the range of 0-3.6 mol%.1H-NMR spectra reveal that the copolymerization proceeds through 1,2-insertion fashion of allene comonomer exclusively,and the regioselective nature maintains under various reaction conditions.The retained intra-chain double bond can be converted into the epoxy group under mild conditions. 相似文献
15.
Ralph-Matthias Schoth Gerd-Volker Röschenthaler 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract The imido derivates of 2-trifluoroacetylphenol, 1 (R1=H, Me, iPr) react with the isocyanatophosphites (R2O)2PNCO, 2 (R2[dbnd]Et, R2-R2[dbnd]CMe2-CMe2) to yield the bicyclic compounds 3, wheras in case of 1 (R1[dbnd](CH2)2NMe2) the λ3σ3P compounds 4 are found. The phosphorus(III) chlorides R3PC12 (R3[dbnd]Ph, OEt) and 1 (R1[dbnd]H, Me) give rise to furnish the tricyclic phosphoranes 5. However with 1 (R1[dbnd]iPr) phosphite 6 is obtained, which adds hexafluoracetone to give the 1,3,2λ5σ5-dioxaphospholane 7. 2-(Trifluoracetoxy)pyridine 8. reacts with Tris(trimethylsily1)phosphite to yield the bis(phosph0nate) 10. Some molecular structures are discussed on the basis of x-ray diffraction results. 相似文献
16.
J. Drabowicz S. Masson C. Mauger W. Midura M. Mikolajczyk J.-F. Saint-Clair 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1)
Abstract As phosphorus-based members of the biologically relevant thiosalicylic acid, monoesters of ortho-sulfinylated phenylphosphonic acids such as 3 and 4 (series a, R1=Me; b, R22-C6H4C02H) are of special interest. They might act both as potential sources of new anionic bidentate ligands for the synthesis of cisplatin analogues[1] and as suitable precursors of phosphorus-containing endocyclic sulfoximides and hypervalent organo-sulfur species. We have therefore undertaken the synthesis of these compounds. The starting phenylphosphonic acid diisopropylesters 1 were formed by using a LDA-induced thiophosphate-mercaptophosphonate rearrangement[2] described earlier and converted into their dimethyl counterpans 2 by means of a trans-silylation procedure followed by alkylation. We have now performed the selective half-hydrolysis of phosphonic acid diesters 1.2 and sulfoxidation of the resulting monoesters. 相似文献
17.
Edwin Weber Annett Zaumüller Wilhelm Seichter Mátyás Czugler 《Supramolecular chemistry》2013,25(4):351-359
Abstract Four new host compounds 1–3 (a, b) derived from malic acid as different optical species and having particular lateral substituents were synthesized. Their properties in crystalline inclusion formation were studied and discussed. Crystal structures of a free host compound 1 and its ethanol inclusion complex [1·EtOH (1:1)] have been determined by X-ray analysis [1: orthorhombic, P212121, a = 9.304(3), b = 14.950(3), c = 15.712(3) Å, Dc = 1.248 Mg·m?3, Z = 4, R = 0.039 for 2474 reflexions; 1·EtOH (1:1): triclinic, P 1; a = 11.945(3), b = 14.080(3), c = 16.029(4) Å, α = 106.82(2), β = 97.74(2), γ = 89.93(2)°, Dc = 1.187 Mg·m3, Z = 4, R = 0.096 for 10404 data]. Spontaneous resolution occurs during crystallization in crystals of 1. An interesting H-bonding pattern develops that probably is responsible for the inclusion formation with ethanol in the associate crystal. 相似文献
18.
V. V. Yanilkin B. I. Buzykin R. M. Eliseenkova N. I. Maksimyuk N. V. Nastapova 《Russian Chemical Bulletin》1999,48(11):2065-2068
Electrochemical reduction of 1-X-1-R1-5-methyl-2-phenyl-7-R2-1,2-dihydro-1,2,4,3-tri-azaphospholo[4,5-a]quinolines1–5 (1: X is the lone electron pair (LEP), R1=Et2N, R2=Me;2: X=LEP, R1=Ph, R2=H;3: X=S, R1=Et2N, R2=H;4: X=LEP, R1=Et2N, R2=H;5: X=LEP, R1=MeO, R2=H) in DMF with 0.1M Bu4NI as supporting electrolyte is reversible and results in metastable radical anions. Radical anions of compounds1–3 efficiently reduce 1,2-dichloro-2-methoxycarbonyl-2-methylcyclopropane both in the presence and in absence of Ni11 ions. Effective reduction rate constants have been evaluated.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2088–2091, November, 1999. 相似文献
19.
A. V. Makarycheva-Mikhailova E. A. Tronova V. Yu. Kukushkin 《Russian Chemical Bulletin》2005,54(3):610-614
The reaction of the nitrile platinum(IV) complex trans-[PtCl4(EtCN)2] with amino acid esters H2NC(R1)(R2)CO2Me (R1 = R2 = H, H-Me, Me-Me, H-Ph) and H2NCH2CH2CO2Me in CH2Cl2 produces the amidine complexes trans-[PtCl4{ Z-NH=C(Et)NHC(R1)(R2)CO2Me}2] and trans-[PtCl4{ Z-NH=C(Et)NHCH2CH2CO2Me}2], which were isolated in 70–80% yields and characterized by elemental analysis, mass spectrometry, IR spectroscopy, and 1H and 13C{1H} NMR spectroscopy. The structures of the complexes with R1 = R2 = H (1), R1 = H, R2 = Me (2), and R1 = H, R2 = Ph (4) were established by X-ray diffraction analysis.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 601–605, March, 2005. 相似文献
20.
C. Paradisi G. Scorrano A. Visentini P. Traldi 《Journal of mass spectrometry : JMS》1986,21(4):171-174
A series of 2-chlorovinyl methyl sulphides, CH3SCR1?CR2Cl (R1, R2 = H, Me, Et, t-Bu, Ph; R1 = H, R2 = CH3) has been analysed under electron impact conditions. The most significant common fragmentations involve primary loss of Cl˙ and methyl radicals. Analysis of the phenyl-substituted derivative suggests that loss of CH3˙ is a lower activation energy process than loss of Cl˙. The characteristic loss of CH3SCl from the same derivative has been examined with respect to the structure of the resulting fragment by means of suitable model compounds. 相似文献