首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
The syntheses of 1∶1‐macrocycles 3 (n=1), unsymmetrical macrocycle 5 (m=0, n=1), 2∶2‐macrocycle 5 (m=n=1 and 2), 3∶3 macrocycle 7, and several open‐chain ethereal compounds prepared from 2,5‐dichloro‐1,3,4‐thiadiazole 1 and various polyethylene glycols dianions are described. Structural proofs are afforded by their mass and NMR spectral features. The quaternization studies of a few macrocycles with methyl iodide at elevated temperature furnished a diketo derivative 8 through a facile Hilbert–Johnson reaction.  相似文献   

2.

Ab initio Hartree–Fock calculations at the HF/6?31 G* level of theory for geometry optimization and the MP2/6?31 G*//HF/6?31 G* and B3LYP/6-311G(2df,p)//HF/6?31 G* levels for a single point total energy calculation are reported for the important energy-minimum conformations of 1-oxo-thiane (1), 1-oxo-1,2-dithiane (2), 1-oxo-1,3-dithiane (3), 1-oxo-1,4-dithiane (4), 1,2-dioxo-1,2-dithiane (5), 1,3-dioxo-1,3-dithiane (6), and 1,4-dioxo-1,4-dithiane (7). According to the MP2/6-31G*//HF/6-31G* calculations, while the axial conformations of compounds 1, 2, and 4 are more stable than the equatorial forms by 6.0, 20.0, and 9.9 kJ mol?1, respectively, the equatorial geometry of 3 is 3.0 kJ mol?1 more stable than the axial form. The diaxial conformations of 5 and 7 are calculated to have similar energies, but the diaxial form of 6 is about 43 kJ mol?1 less stable than that of 5 or 7.  相似文献   

3.
《合成通讯》2013,43(22):3413-3417
ABSTRACT

Conditions for efficient resolution of (±)-1-(9-anthryl)ethylamine ((±)-1) by fractional crystallization of its salts with (S)-(+)-mandelic acid (2) are reported. When crystallization was performed by fast addition of chloroform solution of an equivalent of (±)-1 to the hot chloroform solution of (+)-2, crystals of mandelate of (+)-1-(9-anthryl)ethylamine ((R,S)-3) are collected in 56% yield. (R)-(+)-1 (98.6% e.e.) is isolated by extraction from bicarbonate solution of mandelate salt. Ulterior collection of four crops afforded (R,S)-3 with 71.5% cumulative yield and >98% e.e. of (+)-1 in a any single crop. With only 0.5 equivalents of (+)-2 crystallization afforded (R,S)-3 in 47.4% yield and (+)-1 with 98.1% e.e.  相似文献   

4.
New metallointercalators (1a1e) have been synthesized using the Schiff base, 4-[phenyl(phenylimino)methyl]benzene-1,3-diol and metal(II) ions, viz. Mn(II), Co(II), Ni(II), Cu(II), and Zn(II). They are characterized by analytical and spectral methods. Elemental analyses and molar conductance values reveal that the Schiff base metal(II) complexes have 1?:?2 stoichiometry and are non-electrolytes. The Schiff base (HL) binds with M(II) ions through azomethine and deprotonated phenolic groups. Thermal studies reveal the presence of water in 1a1c. Powder X-ray diffraction and SEM studies show that all the complexes are microcrystalline with homogenous morphology. In vitro biological activities of HL and 1a1e have been screened against bacteria and fungi by well diffusion technique, revealing that these complexes are good antimicrobial agents against various pathogens. The complexes exhibit better biological activities than HL. Complex 1d binds with Calf thymus DNA through intercalation and weak covalent interactions. The oxidative cleavage of 1a1e with pUC 19 DNA has also been explored. The results indicate that they bind to DNA through intercalation and are efficient metallointercalators and cleaving agents.  相似文献   

5.
董南  薛赛凤  陶朱  赵昱 《化学学报》2007,65(11):1045-1050
利用HPLC法考察了六、七元瓜环(Q[6], Q[7])与邻苯二胺(g1)、间苯二胺(g2)、对苯二胺(g3)、邻硝基苯胺(g4)、间硝基苯胺(g5)、对硝基苯胺(g6)的相互作用. 实验结果表明: Q[6]可与客体g1g3, g5形成1∶1的包结配合物; Q[7]与客体g1g6形成1∶1包结配合物, 同时计算了包结配合物的包结稳定常数, 探讨了主-客体的相互作用模式, 并利用1H NMR、紫外吸收光谱法进行了佐证.  相似文献   

6.
Zusammenfassung Beim Behandeln von1-Chloracetylaminofluoren-9-on-oxim (6) mit verd. KOH entsteht 3,4-Dihydro-2H-fluoreno[1,9-ef]-1,4-diazepin-3-on-1-oxid (7); durch Erhitzen von 1-Aminoacetyl-amino-fluoren-9-on (10) sowie durch Kondensation von 1-Aminofluoren-9-on mit Glycinesterhydrochlorid wird 3,4-Dihydro-2H-fluoreno[1,9-ef]-1,4-diazepin-3-on (11) erhalten. Es wird bewiesen, daß es sich bei7 und11 um Derivate des Fluoreno[1,9-ef]-1,4-diazepins (2) handelt und daß7 das 1-Oxid von11 ist. Die Synthesen weiterer Derivate von2 werden beschrieben.
On treating the oxime of 1-chloroacetylaminofluoren-9-one (6) with dilute aqueous potassium hydroxide, 3,4-dihydro-2H-fluoreno[1,9-ef]-1,4-diazepin-3-one-1-oxide (7), is formed; heating of 1-aminoacetylaminofluoren-9-one (10) and condensation of 1-aminofluoren-9-one with glycine ester hydrochloride both yield 3,4-dihydro-2H-fluoreno[1,9-ef]-1,4-diazepin-3-one (11). It is shown that both7 and11 are derivatives of fluoreno[1,9-ef]-1,4-diazepine (2) and that7 is the 1-oxide of11. The syntheses of several other derivatives of2 are reported.


Herrn Prof. Dr.F. Wessely zum 70. Geburtstag.  相似文献   

7.
Stereoselective syntheses on a gram scale of (3Z,6E,8E)-, (3Z,6E,8Z)-and (3Z,6Z,8Z)-3,6,8-dodecatrien-1-ol, 8, 9 and 10, respectively, are described. A key step of the synthesis of 8 consisted of a copper-mediated coupling reaction between 4-(2-tetrahydropyranyloxy)-1-butynylmagnesium bromide (15) and the mesyl ester of (2E,4E)-2,4-octadien-1-ol (14). A similar copper-mediated reaction between 15 and the mesyl ester of (E)-2-octen-4-yn-1-ol (19) was used to construct the C-12 carbon skeleton of 9. On the other hand, the synthesis of 10 was based on a palladium-promoted reaction between (Z)-1-bromo-1-pentene (23) and the organozinc bromide derived from 3,6-heptadiyn-1-yl acetate (27).  相似文献   

8.
James P. Donahue 《合成通讯》2013,43(23):3461-3471
The crystal structures of cis‐3‐iodoacrylic acid (1), trans‐3‐iodoacrylic acid (2), trans‐3‐iodoacrylic acid methyl ester (3), 3,3‐diiodopropanoic acid (4), and trans‐2,3‐diiodoacrylic acid (5) are reported. Compounds 1 and 2 are the kinetic and thermodynamic products, respectively, of the hydroiodination of propiolic acid. Compound 4 results from addition of a second equivalent of hydroiodic acid to 1 or 2, whereas 5 results from the addition of trace elemental iodine to propiolic acid.  相似文献   

9.
The polymeric precursor [RuCl2(CO)2]n reacts with the ligands, P∩P (a, b) and P∩O (c, d), in 1:1 M ratio to generate six-coordinate complexes [RuCl2(CO)2(?2-P∩P)] (1a, 1b) and [RuCl2(CO)2(?2-P∩O)] (1c, 1d), where P∩P: Ph2P(CH2)nPPh2, n = 2(a), 3(b); P∩O: Ph2P(CH2)nP(O)Ph2, n = 2(c), 3(d). The complexes are characterized by elemental analyses, mass spectrometry, thermal studies, IR, and NMR spectroscopy. 1a1d are active in catalyzed transfer hydrogenation of acetophenone and its derivatives to corresponding alcohols with turnover frequency (TOF) of 75–290 h?1. The complexes exhibit higher yield of hydrogenation products than catalyzed by RuCl3 itself. Among 1a1d, the Ru(II) complexes of bidentate phosphine (1a, 1b) show higher efficiency than their monoxide analogs (1c, 1d). However, the recycling experiments with the catalysts for hydrogenation of 4-nitroacetophenone exhibit a different trend in which the catalytic activities of 1a, 1b, and 1d decrease considerably, while 1c shows similar activity during the second run.  相似文献   

10.
The molecular and crystal structures of two diastereomeric 3-oxo-2,3-dihydrobilatrienes-abc1 and2 are determined at low (1, 2) and room temperature (2). The configurations at the exocyclic double bond in position 4 are found to be (Z) for1 and (E) for2. Tautomerism, conformation and crystal packing of1 and2 can be understood on the basis of the pattern of intra- and intermolecular hydrogen bonds. Compared to1, a more open helix conformation is found for the (E) diastereomer2. An analysis of crystallographically observed temperature factors of2 yields the result that the highest flexibility is found for the saturated lactam ring.Herrn Prof.Josef Schurz zum 60. Geburtstag gewidmet.  相似文献   

11.
1-Unsubstituted dihydro-6-methyl-2(1H)-pyrimidinethiones undergo an aminolysis in dialkylformamides or methylformamide resp., at higher temperature, and then are rearranged to 4-dialkylaminodihydro-2(1H)-pyridinethiones6 a, b or the 4-methylamino compound6 c. 1-Alkyl- and 1-aryldihydro-6-methyl-2(1H)-pyrimidinethiones1 b, c and tautom, methylenecompounds2b,c resp., react at the same conditions withDMF not only to 4-alkylamino-or 4-arylaminodihydro-2(1H)-pyridinethiones6 c, d but also to 4-dimethylaminodihydro-2(1H)-pyridinethiones6 a. From 3-substituted dihydro-6-methyl-2(1H)-pyrimidinethiones only the 3-aryl compound12 b is converted byDMF to the corresponding dihydro-4-dimethylamino-1-phenyl-2(1H)-pyridinethione14. Also 4-alkylamino- and 4-arylaminodihydro-2(1H)-pyridones18a, b are formed by heating inDMF at 230°C from 1-alkyl- and 1-aryldihydro-2(1H)-pyrimidinones15b, c and of methylene compounds16b, c resp. 2-Methylimino- and 2-phenyliminodihydro-1,3-thiazinethiones19a, b react inDMF viaDimrothrearrangement to the corresponding 1-alkyl- and 1-phenyl-dihydro-2(1H)-pyrimidinethiones1 b, 2 b, 1 c, 2 c and further to 4-alkylamino-and 4-arylaminodihydro-2(1H)-pyridinethiones6 c, d.  相似文献   

12.
The cyclization of 1,3,5-hexatrien-1-one, 1, and the Z- and E-isomers of 1-aza-1,3-butadienylketene 3 were studied using the semiempirical AM1 and PM3 methods. Cyclizations of compounds 1 and Z-3 are shown to occur via a mono-rotation mechanism with barriers of 15.49 and 32.85 kcal/mol respectively. The reactions proceed via non-planar transition states which result from rotation of the methylene group for compound 1 and the imino group for compound Z-3. Cyclization of E-3 proceeds via a non-rotatory mechanism through a planar transition state. The activation barrier is 4.83 kcal/mol (AM1). The electronic structures of the initial and final states, and of some intermediate structures, including the transition states for the cyclization of compounds 1 and 3, were analyzed by the natural orbital method using HF/6-31G*//AM1 calculations. Energetic, structural, and orbital criteria indicate the heteroelectric mechanism for the cyclization of compound E-3 and the pericyclic mechanism for the cyclization of compounds 1 and Z-3.  相似文献   

13.
((CH3)2Au)2C2O4 (1), ((CH3)2AuSCN)2 (2), (CH3)2AuSSP(OCH3)2 (3), and (CH3)2AuSSP(OC2H5)2 (4) were prepared and recrystallized from hexane to determine their crystal structures and analyze them by thermal methods (TGA). The compounds have been investigated as new possible precursors for metal–organic chemical vapor deposition (MOCVD). Compounds 1 and 2 are solids, while 3 and 4 are liquids. Crystal structures of 1 and 2 have been studied by single-crystal X-ray diffraction (XRD): compounds are monoclinic, space group for 1 P21/c, for 2 P21/n. Compound 1 has crystal parameters a?=?7.6952(5)?Å, b?=?11.1814(8)?Å, c?=?12.2893(8)?Å, α?=?90°, β?=?104.922(4)°, γ?=?90°; 2 has crystal parameters a?=?5.6184(3)?Å, b?=?15.2744(6)?Å, c?=?6.9202(3)?Å, α?=?90°, β?=?102.864(2)°, γ?=?90°. These are neutral complexes, in which molecules are only connected by van der Waal's interactions. Thermal gravimetric analyses (TGA) have shown that 3 and 4 evaporate practically without decomposition. MOCVD experiments were carried out at lower pressure using 3 and 4 as precursors. The films were grown on Si substrate and investigated by XRD and SEM.  相似文献   

14.
Tetrahydro-6-methyl- and-6-phenyl-2-oxopyrimidine-5-carboxylic acids5, 8 resp are obtained on hydrogenolysis of the corresponding benzyl esters4, 7; 1-methyl compounds (5, 8) are also formed by hydrolysis of the ethyl and benzyl esters (3, 4, 6, 7) in alcoholic KOH. Benzyl esters4 which are unsubstituted at position1 are converted by alcoholic KOH into ethyl esters3. Phenols convert3, 4, 5, depending on the substituent in position 1, into 6-hydroxyphenyltetrahydro-2(1H)-pyrimidinones (10) or di(tri)phenylalkanes11, 12. Bromination of the pyrimidine-carboxylic acids5 or of the tert butyl esters18 leads to the 6-bromomethyl- and dibromomethyl derivatives15, 16, which are easily transformed into furo-[3,4-d]pyrimidines17. Thermal decarboxylation of carboxylic acids5 c, f, g lead to dihydro-2(1H)-pyrimidinones13 a, c, d.  相似文献   

15.
A new ligand (L) which consists of cyclotriphosphazene and 1,3,4-oxadiazole units is reported. Two new Ag(I) coordination compounds {[Ag(L)SO3CF3] n (1) and Ag2L2(NO3)2 (2)} based on L and Ag(I) salts are obtained. Compound 1 features a 1-D chain, in which the ligand L adopts a divergent trans-conformation, whereas 2 is a discrete binuclear Ag(I) molecule in which L adopts convergent cis-conformation. Compounds 1 and 2 are fully characterized by 1H-NMR, Infrared, elemental analysis, X-ray powder, and single-crystal diffraction. Luminescent properties of 1 and 2 are investigated.  相似文献   

16.
Abstract

Synthesis of methyl O-β-D-galactopyranosyl-(1→2)-β-D-glucopyranoside 1, methyl O-β-D-galactopyranosyl-(1→3)-β-D-glucopyranoside 2, methyl O-β-D-galactopyranosyl-(1→4)-β-D-glucopyranoside 3, methyl O-β-D-galactopyranosyl-(1→6)-β-D-glucopyranoside 4, methyl O-β-D-galactopyranosyl-(1→4)-[O-β-D-galactopyranosyl-(1→6)]-β-D-glucopyranoside 5, and methyl O-β-D-galactopyranosyl-(1→2)-[O-β-D-galactopyranosyl-(1→3)]-β-D-glucopyranoside 6, using 2,3,4,6 tetra-O-acetyl-α-D-galactopyranosyl trichloroacetimidate or 2,3,4,6 tetra-O-acetyl-α-D-galactopyranosyl bromide as a glycosyl donor and selectively protected derivatives of methyl O-β-D-glucopyranoside as glycosyl acceptors are described.  相似文献   

17.
Abstract

N-Aryl-S,S-dialkylsulfimides, 1, with R1 = alkyl other than CH3, have been rearranged by heating in ethanol yielding o-alkylthiomethyl-anilines, 2, as main products. Isomeric o-methylthioalkyl-anilines, 14, are formed in minor amounts only. Reactions of sulfimides, 1, with R1 = CH3, with certain alkylating or acylating agents yielded o-methylthiomethylated, N-alkylated or -acylated products 9. Mechanistic considerations are discussed. The rearrangement of sulfimides 1 has been assumed to occur via [2,3]-sigmatropic reactions of intermediate azasulfonium ylids 3. Attempts to resolve (+)-camphor-10-sulfonates of N-aryl sulfimides failed, but optically active N-aryl sulfimides could be obtained by reaction of anilines with optically active sulfoxides and P4O10. Optically active 2,6-disubstituted sulfimides, 1, could be rearranged in ethanolic KOH to yield optically active cyclohexadienimines 12, indicating a transfer of asymmetry from sulfur to carbon and supporting the assumption of a sigmatropic rearrangement.  相似文献   

18.
Abstract

Vibrational spectra of (CH3O) n SbCl5–n . n = 1: 1; n = 2: 2: n = 3: 3: n = 4: 4; n = 5: 5; have been recorded. According to ir and Raman data 1–5 are centrosymmetrical bridged dimers. The Raman spectra of 3–5 exhibit v(Sb–O) doublets of terminal CH3O at 530–541 and 550–570 cm?1; vibrations of the 4-membered Sb2O2 ring, observed in the 500–517 cm?1 region of the ir spectra of 1–5, are absent. The v(C–O) bands of bridged and terminal CH3O are shifted to higher wave numbers (60 and 31 cm?1, respectively) in the series 15. The stability of the dimers increases in the series 1 < 2 < 3 < 4 ? 5. At 100–120°C and in CH3CN solutions dimers of 1–3 dissociate to monomers (v(Sb–O) 537–540 cm?1, ir data). The monochloride, 4, is partially dissociated in CH3CN. On solution of the tetrachloride, 1, in benzene a dimer-monomer equilibrium has been observed, with the dimeric form being predominant.  相似文献   

19.
Abstract

The reactivity of 1-alkyl-1,2-diphospholes in cycloaddition reactions with dienes, dienophiles or 1,3-dipoles was examined. 1-Alkyl-1,2-diphospholes (2 ) exhibit dual reactivity and act as diene toward maleic acid derivatives or as dienophiles with 2,3-dimethyl-1,3-butadiene. The 1-alkenyl-1,2-diphospholes (4 ) are readily involved in intramolecular [4 + 2] cycloaddition reactions leading to cage phosphines (5 ). Interaction of 1-alkyl-1,2-diphospholes (2) with 1,3-dipolar reagents (diphenyldiazomethane and nitrones) results in formation of the bicyclic phosphiranes (8) and dimers of 1-alkyl-1,2-diphosphole oxides (9) or bicyclic phosphine oxides (10) with a β-lactam moiety depending on temperature.  相似文献   

20.
Summary Alkyl ketone hydrazones1 are oxidized withtert-butylhypochlorite to give geminal chloro azo compounds2. These react with SbCl5 to give 1-aza-2-azonia-allene salts3 as reactive intermediates which are intercepted with nitriles to yield 3H-1,2,4-triazolium salts5. In most cases these salts rearrange spontaneously to form 1H-triazolium salts6. Hydrolysis of6e–g by NaOH provide bases7a–c, which react with picric acid to give 1H-pyrazolium picrates8.
Synthese von 1,2,4-Triazoliumsalzen: Reaktion von 1-Azo-2-azonia-allensalzen mit Nitrilen
Zusammenfassung Alkylketonhydrazone1 werden durchtert-Butylhypochlorit zu geminalen Chlorazoverbindungen2 oxidiert. Diese reagieren mit SbCl5 zu 1-Aza-2-azonia-allensalzen3, welche mit Nitrilen unter Bildung von 3H-1,2,4-Triazoliumsalzen5 abgefangen werden. In den meisten Fällen lagern diese spontan zu 1H-Triazoliumsalzen6 um. Hydrolyse von6e–g mit NaOH führt zu den Basen7a–c, welche mit Pikrinsäure 1H-Pyrazoliumpikrate8 bilden.
  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号