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1.
The rates of rearrangement in 1-phenyl-2,4,6-tris(p-methoxyphenyl)thiabenzene (4) and 1-(p-tri-fluoromethylphenyl)-2,4,6-triphenylthiabenzene (5) were determined and a crossover experiment was carried out with a mixture of these thiabenzenes. The possibility of 2,4-migrations in the thiopyran system under the reaction conditions was also studied by examining two samples of thiopyrans. The results indicate an intramolecular rearrangement which involves a 1,2- and 1,4-migration of 5-aryl groups in thiabenzenes.  相似文献   

2.
The room‐temperature crystal structures of four new thio derivatives of N‐methylphenobarbital [systematic name: 5‐ethyl‐1‐methyl‐5‐phenylpyrimidine‐2,4,6(1H,3H,5H)‐trione], C13H14N2O3, are compared with the structure of the parent compound. The sulfur substituents in N‐methyl‐2‐thiophenobarbital [5‐ethyl‐1‐methyl‐5‐phenyl‐2‐thioxo‐1,2‐dihydropyrimidine‐4,6(3H,5H)‐dione], C13H14N2O2S, N‐methyl‐4‐thiophenobarbital [5‐ethyl‐1‐methyl‐5‐phenyl‐4‐thioxo‐3,4‐dihydropyrimidine‐2,6(1H,5H)‐dione], C13H14N2O2S, and N‐methyl‐2,4,6‐trithiophenobarbital [5‐ethyl‐1‐methyl‐5‐phenylpyrimidine‐2,4,6(1H,3H,5H)‐trithione], C13H14N2S3, preserve the heterocyclic ring puckering observed for N‐methylphenobarbital (a half‐chair conformation), whereas in N‐methyl‐2,4‐dithiophenobarbital [5‐ethyl‐1‐methyl‐5‐phenyl‐2,4‐dithioxo‐1,2,3,4‐tetrahydropyrimidine‐6(5H)‐one], C13H14N2OS2, significant flattening of the ring was detected. The number and positions of the sulfur substituents influence the packing and hydrogen‐bonding patterns of the derivatives. In the cases of the 2‐thio, 4‐thio and 2,4,6‐trithio derivatives, there is a preference for the formation of a ring motif of the R22(8) type, which is also a characteristic of N‐methylphenobarbital, whereas a C(6) chain forms in the 2,4‐dithio derivative. The preferences for hydrogen‐bond formation, which follow the sequence of acceptor position 4 > 2 > 6, confirm the differences in the nucleophilic properties of the C atoms of the heterocyclic ring and are consistent with the course of N‐methylphenobarbital thionation reactions.  相似文献   

3.
Heterobimetallic Phosphanido-bridged Dinuclear Complexes - Syntheses of cis-rac-[(η-C5H4R)2Zr{μ-PH(2,4,6-iPr3C6H2)}2M(CO)4] (R?Me, M?Cr, Mo; R?H, M?Mo) The zirconocene bisphosphanido complexes [(η-C5H4R)2Zr{PH(2,4,6-iPr3C6H2)}2] (R?Me, H) react with [(NBD)M(CO)4] (NBD?norbornadiene, M?Cr, Mo) to give only one diastereomer of the phosphanido-bridged heterobimetallic dinuclear complexes cis-rac-[(η-C5H4R)2Zr{μ-PH(2,4,6-iPr3C6H2)}2M(CO)4] [R?Me, M?Cr ( 1 ), Mo ( 2 ); R?H, M?Mo ( 3 )]. However, no reaction was observed between [(η-C5H5)2Zr{PH(2,4,6-tBu3 C6H2)}2] and [Pt(PPh3)4]. 1—3 were characterised spectroscopically. For 1—3 , the presence of the racemic isomer was shown by NMR spectroscopy. No reaction was observed at room temperature for 3 and CS2, (NO)BF4, Me3NO or PH(2,4,6-Me3C6H2)2. With Et2AlH or PhC?CH decomposition of 3 was observed.  相似文献   

4.
2-Oxo-2H-1,4-benzoxazin-3-yl-(2,4,6-trimethylbenzoyl)ketene, which is generated upon thermal decarbonylation of 3-(2,4,6-trimethylbenzoyl)pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-trione, undergoes dimerization through [4+2] cycloaddition to give 2-(2-oxo-2H-1,4-benzoxazin-3-yl)-4-(2,4,6-trimethylbenzoyl)-3-(2,4,6-trimethylbenzoyloxy)pyrido[2,1-c]-[1,4]benzoxazine-1,5-dione. The resulting compounds formed a crystal solvate withp-xylene, whose crystal and molecular structure was established by X-ray diffraction analysis.  相似文献   

5.
Synthesis and Structure of Copper(I)Chalcogenolate-2,2′-Bipyridine Complexes [CuS(2,4,6-iPr3C6H2)]4(Bipy)2 and [CuSe(2,4,6-iPr3C6H2)]2(Bipy)2 The oligomeric homoleptical copper(I) chalcogenolate compounds [CuS(2,4,6-iPr3C6H2)]x=4,8 and [CuSe(2,4,6-iPr3C6H2)]6 react with 2,2′-bipyridine (Bipy) to yield the tetranuclear complex [CuS(2,4,6-iPr3C6H2)]4(Bipy)2 ( 4 ) and the dinuclear complex [CuSe(2,4,6-iPr3C6H2)]2(Bipy)2 ( 5 ). The structures of 4 and 5 were determined by X-ray analysis. In the eight-membered Cu4S4 core of 4 with chair conformation the copper atoms are linked by μ2-bridging selenolate ligands. Only two copper atoms are coordinated by 2,2′bipyridine. The corresponding copper(I) selenolate complex ( 5 ) forms a folded four-membered Cu2Se2 ring with μ2-bridging selenolate ligands. The Cu? Cu distance of 2.52 Å is relatively short. In contrast to the reaction performed with 2,2′-bipyridine, addition of phenantroline to 1 respectively 2 yields a dinuclear complex [CuS(2,4,6-iPr3C6H2)]2(Phen)2 ( 10 ). NMR spectroskopic and cryoscopic measurement of 4 show that this complex dissociates into smaller fragments in solution which undergo rapid exchange reactions. However, corresponding investigations performed on 5 indicate that the solid state structure is maintained in solution. The electrochemical behaviour of 4, 5 and 10 was studied in CH2Cl2 and in any case no reversible redox processes could be observed.  相似文献   

6.
The preparation of ylides of the general structure is described. Thermolysis of 14a (R = CH3, R' = H, Ar = C6H5) gave dimethylamine and 2,4-dimethyl-6-phenyl-s-triazine. Thermolysis of ylides 14b (R = C6H5; R' = CH3, Ar = C6H5) and 14c (R = C6H5, R' = CH3, Ar = p-tolyl) gave dimethylamine, ArCH = NCH3 and 1-methyl-2-Ar-4,6-diphenyl-1,2-dihydro-s-triazines ( 19a,b ). Triazines 19a and 19b were also prepared by condensation of N-methylbenzamidine with benzaldehyde and p-tolualdehyde, respectively. Thermolysis of 14d (R = C6H5, R1 = CH2C6H5,Ar = C6H5) gave 1-benzyl-2,4,6-triphenyl-1,2-dihydro-s-triazine ( 19c ) and N-benzylidenebenzylamine. Mechanistic aspects of these reactions are discussed.  相似文献   

7.
Coordinatively Unsaturated Iron Chalcogenolate Complexes with Trigonal Planar Ligand Spheres – Synthesis, Properties, and Reactions with Nitrogen and Oxygen Donor Molecules The new bulky organo-selenium compound 2,4,6-triphenylbenzeneselenole ( 1 A ) was synthesized by a multistep-reaction from 1,3,5-triphenylbenzene. 1 A was converted by oxidation into the air-stable bis(2,4,6-triphenylphenyl)diselenide ( 1 B ), which was characterized by X-ray diffraction. The stepwise reaction of [Fe2{N(SiMe3)2}4] with 1 A leads to the complexes [Fe2(SeC6H2-2,4,6-Ph3)2{N(SiMe3)2}2] ( 2 ) and [Fe2(SeC6H2-2,4,6-Ph3)4] ( 3 ), controlled by their molar ratios. The conversion of 2 to 3 is also described. In addition, the coordinatively unsaturated thiolate complexes [Fe2{SC6H3-2,6-(SiMe3)2}2{N(SiMe3)2}2] ( 4 ) and [Fe2{SC6H3-2,6-(SiMe3)2}4] ( 5 ) were synthesized by stepwise reaction of [Fe2{N(SiMe3)2}4] with 2,6-bis(trimethylsilyl)benzenethiole. It is also possible to convert the heteroleptic compound 4 into the homoleptic thiolate complex 5 . During our investigations of the reactivity of 5 towards small electroneutral molecules, the compounds [Fe2{SC6H3-2,6-(SiMe3)2}4 · (MeCN)2] ( 6 ) and [Fe{SC6H3-2,6-(SiMe3)2}2(OPEt3)] ( 7 ) were obtained. 6 is the product of the addition of two molecules of acetonitrile to 5 . The iron atoms of 6 are coordinated by three sulfur and one nitrogen atom in a distorted tetrahedral manner. When 5 is treated with triethylphosphine oxide instead of acetonitrile, the mononuclear complex 7 with the coordination number three is formed. The iron atom is surrounded by two sulfur and one oxygen donor functions.  相似文献   

8.
The crystals of a new melaminium salt, 2,4,6‐tri­amino‐1,3,5‐triazine‐1,3‐diium bis(4‐hydroxy­benzene­sulfonate) dihydrate, C3H8N62+·2C6H5O4S?·2H2O, are built up from doubly proton­ated melaminium(2+) residues, dissociated p‐phenol­sulfonate anions and water mol­ecules. The doubly protonated melaminium dication lies on a twofold axis. The hydroxyl group of the p‐hydroxybenzenesulfonate residue is roughly coplanar with the phenyl ring [dihedral angle 13 (2)°]. A combination of ionic and donor–acceptor hydrogen‐bond interactions link the melaminium and p‐hydroxybenzenesulfonate residues and the water mol­ecules to form a three‐dimensional network.  相似文献   

9.
The extractability of palladium nitro complexes with the charge state of sulfur and oxygen atoms in thiacalix[4]arenas in the cone and 1,3-alternate conformations are compared. The results of X-ray photoelectron and X-ray emission studies indicate the presence of considerable electron density on the bridging sulfur atoms, which is due to the contribution of the sulfur 3p AO to the upper occupied MOs of molecules. A series of changes in the electron density on sulfur atoms in the order calixarene thioethers > thiacalixarenes > dialkylsulfides ((C10H21)2S) > (C6H5)2S not completely coincide with changes in their extrability, which can be caused by different nature and stoichiometry of the formed palladium complexes.  相似文献   

10.
Fifteen [C6H5(X)FeCp]+ cations with substituents X having different electron-donating or electron-withdrawing effects were treated with NaBH4 in glyme or THF. The relative distributions of products from o-, m-, p- and ipso-additions of the hydride ion to the arene ring were determined by high resolution 1H NMR. For the η6-N,N-dimethylaniline-η5-cyclopentadienyliron cation with the most electron-donating of the substituents studied, only m- and p-hydride addition products were obtained, while in the reaction with the η6-nitrobenzene-η5-cyclopentadienyliron cation, which contained the most electron-withdrawing of the substituents investigated, only the o-addition product was formed. For the other 13 cations, with X  C6H5O, CH3O, p-CH3C6H4S, C6H5CH2, (CH3)3C, CH3, CH3CH2, C6H5, Cl, COOCH3, C6H5CO, CN and p-CH3C6H4SO2, o-, m- and p-hydride addition products were obtained in all cases, with a few instances also giving very minor amounts of ipso-adducts. The relative product distributions observed were interpreted by suggesting that while electronic effects played a major role, steric factors and free valency effects favoring o-addition as suggested by MO calculations [5] could also exert their influence in giving rise to the overall results.  相似文献   

11.
1H-NMR data (11.74 Tesla) for the gold(I) complexes [R3P-Au-(2,3,4, 6-tetra-O-acetyl-1-thio-β-D -glucopyranosido-S)] (R = Et, Cyclohexyl, C6H5, p-CH3OC6H4) with sulfur coordination to gold, are reported. The resonances associated with the sugar protons have been assigned although these have similar chemical environments. The coordination chemical shifts, Δδ, for the Au? S? C? H proton are ≈? 0.6 ppm, and support S-coordination to gold.  相似文献   

12.
Abstract

The reaction of sulfimides with hydroxide ion in methanol gave the corresponding sulfoxide (the solvolysis product) and/or the corresponding α-methoxysulfide (the Pummerer type product). The pseudo first order rates for the solvolysis reaction and the Pummerer type reaction were determined using a large excess of potassium hydroxide. The rates of the solvolyses are correlated with [sgrave] values and the values of ρ X = +1.2 and ρ Y = +0.8 were obtained for aryl methyl N-aryl-sulfonylsulfimides (p-XC6H4S(NSO2C6H4Y-p)CH3), and both the activation enthalpy and entropy calculated are δH≠ = 18.8 kcal mol?1 and δS≠ = –23.9 e.u. (PhS(NSO2C6H4CH3-p)CH3), respectively. Hammett correlation with [sgrave] values for the Pummerer type reaction gave ρz = +2.0 for N-aryl-sulfonyltetramethylenesulfimides ((CH2)4SNSO2C6H4Z-p), and the activation enthalpy and entropy are δH≠ = 27.9 kcal mol?1 and δS≠ = +13.3 eu ((CH2)4SNSO2C6H4CH3-p), respectively. All these observations suggest that the solvolysis reaction proceeds via the initial nucleophilic attack of hydroxide ion on the sulfur atom of the sulfimide namely via an S N 2 process at the sulfur atom whereas the Pummerer type reaction proceeds by way of the E 1cb mechanism.  相似文献   

13.
Uniform quality basis sets (UQ-NG ; N=3, 4, 5), with s = p and sp, and a 6-31 G* basis set have been optimized for the sulfur atom. These uniform quality basis sets in their uncontracted and contracted forms were used, together with other basis sets reported in the literature (a total of 40 basis sets), to study their accuracy in predicting the bond length and bond angle of H2S.  相似文献   

14.
We report a facile approach for the synthesis of homochiral 1,2-disubstituted ferrocene-functionalized Lewis acids and acid/base pairs. The synthesis is based on chiral induction facilitated by the ortho sulfinyl subsitutent in S-Fc{S(O)p-tol}, S-1, to obtain the key intermediate S,Sp-1,2-fc{S(O)p-tol}(BMes2), S,Sp-2a (p-tol = C6H4Me-4, Mes = C6H2Me3-2,4,6). Subsequent substitution of the -S(O)p-tol substituent in S,Sp-2a gives access to a range of enantiomerically pure Sp-1,2-ferrocene-functionalized Lewis acids and acid/base pairs including the first homochiral 1-phosphino-2-borylferrocene. Enantiomeric excesses (e.e.s) of >95% have typically been achieved using this methodology.  相似文献   

15.
The primary phosphines MesPH2 and tBuPH2 react with 9-iodo-m-carborane yielding B9-connected secondary carboranylphosphines 1,7-H2C2B10H9-9-PHR (R=2,4,6-Me3C6H2 (Mes; 1 a ), tBu ( 1 b )). Addition of tris(pentafluorophenyl)borane (BCF) to 1 a , b resulted in the zwitterionic compounds 1,7-H2C2B10H9-9-PHR(p-C6F4)BF(C6F5)2 ( 2 a , b ) through nucleophilic para substitution of a C6F5 ring followed by fluoride transfer to boron. Further reaction with Me2SiHCl prompted a H−F exchange yielding the zwitterionic compounds 1,7-H2C2B10H9-9-PHR(p-C6F4)BH(C6F5)2 ( 3 a , b ). The reaction of 2 a , b with one equivalent of R'MgBr (R’=Me, Ph) gave the extremely water-sensitive frustrated Lewis pairs 1,7-H2C2B10H9-9-PR(p-C6F4)B(C6F5)2 ( 4 a , b ). Hydrolysis of the B−C6F4 bond in 4 a , b gave the first tertiary B-carboranyl phosphines with three distinct substituents, 1,7-H2C2B10H9-9-PR(p-C6F4H) ( 5 a , b ). Deprotonation of the zwitterionic compounds 2 a , b and 3 a , b formed anionic phosphines [1,7-H2C2B10H9-9-PR(p-C6F4)BX(C6F5)2][DMSOH]+ (R=Mes, X=F ( 6 a ), R=tBu, X=F ( 6 b ); R=Mes, X=H ( 7 a ), R=tBu, X=H ( 7 b )). Reaction of 2 a , b with an excess of Grignard reagents resulted in the addition of R’ at the boron atom yielding the anions [1,7-H2C2B10H9-9-PR(p-C6F4)BR’(C6F5)2] (R=Mes, R’=Me ( 8 a ), R=tBu, R’=Me ( 8 b ); R=Mes, R’=Ph ( 9 a ), R=tBu, R’=Ph ( 9 b )) with [MgBr(Et2O)n]+ as counterion. The ability of the zwitterionic compounds 3 a , b to hydrogenate imines as well as the Brønsted acidity of 3 a were investigated.  相似文献   

16.
Through complexation reaction of arynyl Fe-S complexes A (μ-p-CH3C6H4C≡CS) (μ-RS) Fe2 (CO)6 with Co2 (CO)8, eight mixed cluster complexes B [μ-p-CH3C6H4C2Co2 (CO)6S](μ-RS) Fe2 (CO)6 have been synthesized. Reactivity of the complexation reaction is approximately equivalent to that of the reaction of diarylacetylene with Co2 (CO)8. Conformational analysis has shown that R groups in complexes A are linked to sulfur atoms by a- and e-bond, whereas that in B only by an e-type of bond.  相似文献   

17.
The first complete pH-rate profile (HO-4 ÷ pH 12) for an amide is reported. Hydration of carbonyl moiety is suggested to be the first step of the reaction between HO-4 ÷ pH 6.  相似文献   

18.
Investigations on Syntheses and Reactions of Fluorophenylmercury Compounds with the Ligands 2-FC6H4, 2,6-F2C6H3, and 2,4,6-F3C6H2 2,6-F2C6H3HgCl and 2,4,6-F3C6H2HgCl are synthesized via the reactions of the corresponding phenylmagnesium compounds and HgCl2. 2-FC6H4HgCl is selectively obtained only in a reaction involving intermediately formed Cd(2-FC6H4)2. The diphenylmercury derivative Hg(2,4,6-F3C6H2)2 is obtained while stirring a dichloromethane solution of 2,4,6-F3C6H2HgCl for several days. The direct mercuration of 1,3,5-trifluorobenzene with Hg(OCOCF3)2 yields, depending on the stoichiometry, 2,4,6-trifluorophenylmercury trifluoroacetate and 1,3-bis(trifluoroacetatomercuri)-2,4,6-trifluorobenzene which is converted into the corresponding chloromercuri derivative by treatment with hydrochloric acid in CH3CN. As a product of the reaction of 1,3,5-trifluorobenzene and HgO in CH3COOH only 2,4,6-trifluorophenylmercury acetate is isolated although spectroscopic evidence has been found for double and triple mercurated derivatives. All compounds are characterized by elemental analyses, nmr and mass spectra. The reaction of Hg(2,4,6-F3C6H2)Cl and Cd(CF3)2 · 2 CH3CN gives Hg(2,4,6-F3C6H2)CF3 which slowly dismutates in CH2Cl2 solution into Hg(2,4,6-F3C6H2)2 and Hg(CF3)2. The ligand exchange of Hg(2,4,6-F3C6H2)2 and TeCl4 selectively gives Te(2,4,6-F3C6H2)2Cl2 and Hg(2,4,6-F3C6H2)Cl. Transmetalations of Hg(2,4,6-F3C6H2)2 and gallium or tin give NMR spectroscopic evidence for the new derivates Ga(2,4,6-F3C6H2)3 and Sn(2,4,6-F3C6H2)4.  相似文献   

19.
Recently, experimental and theoretical determination of electric currents induced by finite bias voltages in p‐xylylene chains attached to gold contacts revealed higher conductance of these systems in comparison with p‐phenylene homologous chains. To gain more insight into the conducting properties of these oligophenyl structures, ab initio studies were carried out on the electronic properties of two different p‐xylylene‐like chains (pX1 and pX2) and the p‐phenylene (pP) chain attached to gold contacts, with molecular formulas AuCH2(C6H4)nCH2Au (n=1–5), Au2C(C6H4)nCAu2 (n=1–5), and Au(C6H4)nAu (n=1–5), respectively. The molecules were subjected to finite bias voltages ranging from 0 to 5 V. Analysis of the intramolecular electron transfer and electron delocalization revealed a completely opposite response to electric perturbation of pX2 in comparison with pX1 and pP. Thus, in pX2 the applied voltage causes an increase in the electron delocalization within the rings together with a large electron transfer and energetic stabilization. On the contrary, the same voltages partially destroy the electron delocalization in pX1 and pP, produce a large local electron polarization in the benzene rings, and a smaller energetic stabilization. These differences can be rationalized in terms of the role played by polarized valence bond structures in the total wave function. Theoretical estimation of the I/V profiles indicates that pX2 chains are much better electronic conductors than pX1 and pP.  相似文献   

20.
The organomercury compounds HgR2 (R = 2-Cl,6-FC6H3, 2,6-F2C6H3, 2,3,6-F3C6H2, m-HC6F4, p-HC6F4, or C6F5) and RHg(O2CR) (R = 2-Cl,6-C6H3, 2,6-F2C6H3 or 2,3,6-F3C6H2) have been obtained in moderate – good and low yields respectively from decarboxylation reactions of the corresponding mercury(II) fluorobenzoates in boiling pyridine. By contrast, mercury(II) 2,3,4-5-tetrafluorobenzoate gave a low yield of CO2, a trace of Hg(o-HC6F4)2 and a very low yield of o-HC6F4Hg(O2CC6F4H-o). The 199Hg NMR spectra of the diorganomercurials (R = 2-Cl,6-FC6H3, 2,6-F2C6H3, 2,3,6-F3C6H2, 2,4,6-F3C6H2, 2,6-Cl2C6H3, o-HC6F4, m-HC6F4, p-HC6F4 or C6F5) are discussed.  相似文献   

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