The 2,4-bis-functionalized phenol 1 is dehydrogenated regioselectivity with potassium ferricyanide, affording the corresponding p-quinonemethide 2 . Hydrolysis of 2 affords a mixture of dithioacetal 5a and benzaldehyde 6 ; 1,6-addition of thiols to 2 gives the dithioacetals 5 of benzaldehyde 6 ; reaction of 2 with 2,2′-azobis(isobutyronitrile) (= 2,2′-dimethyl-2,2′-azobis(propanenitrile)) leads to 9a, 9b , and 10 , addition products of the 1-cyano-1-methylethyl radical. The structures of all products are confirmed mainly by 1H- and 13C-NMR spectroscopy, and the mode of their formation is discussed. 相似文献
Condensation of 4-bromo- ( 4 ) and 4-nilro-l,8-naphthalimides ( 5 ) with 2-aminobenzenethiol gave 4-(2-aminoulicnylthio)-1,8-naphthalimides ( 7 ). Cyclisalion of 7 by the: Pschorr reaction afforded benzo[k,l] thioxanthene-3,4-dicarboximides ( 8 ), also obtained by reaction ol amities with benzo[k,l] thioxanthene-3,4-dicarboxylie anhydride ( 11 ). 相似文献
5,6,7,8-Tetrafluoro-4-hydroxy-2H-chromen-2-one reacts with methylamine to give methylammonium 5,6,7,8-tetrafluoro-2-oxo-2H-chromen-4-olate, regardless of the solvent. The reaction of 3-acetyl-5,6,7,8-tetrafluoro-4-hydroxy-2H-chromen-2-one with the same amine in ethanol or acetonitrile leads to the formation of methylammonium 3-acetyl-5,6,7,8-tetrafluoro-2-oxo-2H-chromen-4-olate, while in dimethyl sulfoxide 5,6,8-trifluoro-7-methylamino-3-(1-methylaminoethylidene)-3,4-dihydro-2H-chromene-2,4-dione is formed. The latter is also formed in the reaction of 5,6,7,8-tetrafluoro-4-hydroxy-3-(1-iminoethyl)-2H-chromen-2-one with methylamine in DMSO, whereas in ethanol and acetonitrile 5,6,7,8-tetrafluoro-3-(1-methylaminoethylidene)-3,4-dihydro-2H-chromene-2,4-dione is obtained. 5,6,7,8-Tetrafluoro-3-(1-methylaminoethylidene)-3,4-dihydro-2H-chromene-2,4-dione reacts with methylamine, yielding 7-mono-or 5,7-bis(methylamino)-substituted derivatives. 相似文献
The polymerization of methylated β‐cyclodextrin (m‐β‐CD) 1 : 1 host‐guest compounds of methyl methacrylate (MMA) ( 1 ) or styrene ( 2 ) is described. The polymerization of complexes 1 a and 2 a was carried out in water with potassium peroxodisulfate (K2S2O8)/sodium hydrogensulfite (NaHSO3) as radical redox initiator at 60°C. Unthreading of m‐β‐CD during the polymerization led to water‐insoluble poly(methyl methacrylate) (PMMA) ( 3 ) and polystyrene ( 4 ). By comparison, analogously prepared polymers from uncomplexed monomers 1 and 2 in ethanol as organic solvent with 2,2′‐azoisobutyronitrile (AIBN) as radical initiator showed significantly lower molecular weights and were obtained in lower yields in all cases. Polymerization of m‐β‐CD complexed MMA in water, initiated with 2,2′‐azobis(N,N ′‐dimethyleneisobutyroamidine) dihydrochloride, occurred much faster than the polymerization of uncomplexed MMA in methanol under similar conditions. Furthermore, it was shown, that the precipitation polymerization of complexed MMA from homogeneous aqueous solution can be described by equations (Pn–1 ∝ lsqb;Irsqb;0.5) similar to those for classical polymerization in solution. 相似文献
The reaction of aminofluorsilanes of the type (R=H,F) (Me3Si)2N?SiF2R with two moles of ammonia, or of a mono- or dialkylamine, yields the corresponding amino-compounds, e.g. (Me3Si)2N?Si(F)R?NH2, (Me3Si)2N?Si(F)R?NHR′ and (Me3Si)2N?Si(F)R?NR2′ (R′=Me, Et). Analogous products are obtained by reaction of the aminofluorosilanes with lithium salts of amines with bulky organic substituents in a 1 : 1 molar ratio. Alkoxy- and aryloxyaminofluorosilanes are prepared by the reaction of sodium alcoholates and sodium phenolate with (Me3Si)2N?Si(F2)R (R=H, C2H3, C2H5, C6H5). The i.r.-, mass-,1H- and19F-NMR spectra of the above compounds are reported. 相似文献
Atom transfer polymerization of styrene using N-aryl-substituted pyridinimines and N,N′-diaryl-substituted diimines as N,N′-ligands in the presence of Cu(I)Br and 1-phenylethyl bromide has been investigated and compared with the analogous 2,2′-bipyridine system. A molar mass increase which is consistent for a controlled polymerization with a target molar mass of 10000 g · mol−1 is observed with the 2,2′-bipyridine ( 1 ) and the pyridinimine ( 2a ) systems. The polymerization of styrene with the N,N′-diimine system ( 3 ) is much less controlled, yielding polymers with higher molar masses than expected. 相似文献
Kinetics of 2,2′-azobisisobutyronitrile initiated polymerization of styrene in N,N-dimethylformamide (DMF) were investigated in the presence of dichloro bis(N,N-dimethylformamide)copper(II) complex. The complex was prepared in situ by mixing tetrakis(N,N-dimethylformamide)copper(II) perchlorate with LiCl in the molar ratio of 1:2. The equilibrium constant for was calculated by the limiting logarithmic method as 1.07 × 1010 l2 mol?2. The velocity constant at 60 for the interaction of polystyryl radical with Cu(DMF)2Cl2 is 2.16 × 104 l. mol?1 sec?1. 相似文献
Abstract The poly-Diels-Alder addition between the new bisdiene 1,4-bis(5-methoxy-2-oxazolyl)benzene (4) and N,N′-hexamethylene-bis[2-(2,5-dihydro-2,5-dioxo-pyrrole-1-yl) acetamide] (7) is described. The structure of the resulting polyadduct 12 was proved by 1H NMR spectroscopy with the aid of the low-molecular-weight model compounds 1,4-bis(1,3-dihydro-7-hydroxy-1,3-dioxo-2-phenyl-pyrrolo[3,4-c] pyridine-4-yl)benzene (9) and N,N'-hexamethylene-bis[2-(1, 3-dihydro-7-hydroxy-6-methyl-1,3-dioxo-4-phenyl-pyrrolo [3,4-c]pyridine-2-yl)acetamide] (11). The reaction proceeds via the aromatization of the primarily formed cycloadducts. Polyadduct 12 shows a number average degree of polymerization Pn of about 11 – 12 (Mn = 8500 ? 9200 g/mol), calculated from 1H NMR endgroup signals. 相似文献
Formation of Intramolecularly Stabilized Diazaphosphorinane Derivatives with the Trimethylethylenediamine and the Tetramethylguanidine Group as Substituents at Phosphorus: Investigation of intramolecular Me2N → P Interactions In the reaction of trimethylchlorophosphonium chloride 1 with N-trimethylsilyl-N′,N′,N″,N″-tetramethylguanidine 2 the expected guanidine-substituted trimethylphosphonium chloride 3 was formed, presumably via the ammonium chloride 3a which could not be isolated. By contrast, the reaction of the related chloromethyldimethylchlorophosphonium chloride 5 with N-trimethylsilyl-N,N′,N′-trimethylethylenediamine 6 and N-trimethylsilyl-N′,N′-dimethylethylene diamine, 7 , respectively, furnished in an unusual fashion six-membered heterocycles, the ammonium-phosphonium dichlorides 10 and 11 . Their formation involved cleavage of both the P? Cl and the C? Cl bond, followed by intramolecular C←N-acceptor-donor interaction. A similar C←N interaction was not observed in the reaction of 5 with 2 , and the acyclic product 12 was formed. The reaction of chloromethylmethylchlorophosphine 13 with the hydrogen peroxide/urea 1:1-adduct led to chloromethylmethylphosphinic acid 14 . Attempts at the reaction of 14 with 2 or with SOCl2 were unsuccessful. The reaction products were characterized by 1H-, 13C-, 31P- and, in two cases, by 15N-NMR-spectroscopy. 相似文献
The reactivity of 1-phenylbutadiene (1-PBD) in cationic polymerization and the monomer structure were investigated. 1-PBD polymerized at ?78°C in several solvents initiated by cationic catalysts such as stannic chloride and tungsten hexachloride. The polymerizations proceeded predominantly via 3,4-type propagation mode, and gave low molecular weight polymers. More than one double bond of 1-PBD was consumed during the polymerizations, probably due to transfer and cyclization reactions. 1-PBD was several times as reactive as styrene and trans-1,3-pentadiene in copolymerizations. The Hammett plots of reactivities of ring-substituted 1-PBD in cationic polymerization gave the p-value of -1.20, which is 0.6 times that of styrene. The 1H and 13C NMR chemical shifts of ring-substituted 1-PBD were measured and discussed in relation to the reaction mechanism. 相似文献
2-Ethoxycarbonyl-5,6,7,8-tetrafluorochromone reacts with methylamine differently, depending on the solvent nature and the
amount of the amine: in DMSO and MeCN, the fluorine atom at the C(7) atom is initially replaced and then the C(2) and/or C(9)
are attacked, while in ethanol, the reaction involves the C(2) atom with opening of the pyrone ring. The reaction of 3-ethoxycarbonyl-5,6,7,8-tetrafluoro-2-methylchromone
with methylamine results, regardless of the solvent, in opening of the chromone ring and the formation of intermediate ethyl
3-(3,4,5,6-tetrafluoro-2-hydroxyphenyl)-2-(1-methylamino)ethylidene-3-oxopropionate, which undergoes intramolecular cyclization
to give 5,6,7,8-tetrafluoro-3-(1-methyl-amino)ethylidene-3,4-dihydro-2H-benzopyran-2,4-dione.
Dedicated to Academician N. S. Zefirov on the occasion of his 70th birthday.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2093–2098, September, 2005. 相似文献
Mercury(II) complex, [Hg((3,4-MeO-Bza)2En)I2] (I), where (3,4-MeO-Bza)2En = N,N′-bis(3,4-dimethoxybenzaldehyde)ethylenediimine, has been synthesized from the reaction of HgI2 with (3,4-MeO-Bza)2En in methanol as solvent at 50°C. It was characterized by elemental analysis (CHN), 1H-NMR spectroscopy and confirmed by single-crystal X-ray diffraction analysis. The complex I crystallizes in the monoclinic system, with space group P21/c, having one symmetry-independent Hg2+ ion coordinated in a distorted tetrahedral geometry by two N atoms of the Schiff base ligand and by two I atoms. The Schiff base ligand (3,4-MeO-Bza)2En acts as a chelating ligand and coordinates via two N atoms to the mercury center. It adopts an (E, E) conformation. 相似文献
The reactions of N,N′-dimethyl-N,N′-bis(trimethylsilyl)urea 8 and N-methyl-N′-phenyl-N,N′-bis(trimethylsilyl)urea 9 with phenylselenenyl chloride 6 and p-chlorophenylselenenyl chloride 7 furnished the N-arylseleno-N,N′-diorgano-N′-(trimethylsilyl)ureas 10–13 . The reactions of 10–13 with MePCl2 and PhPCl2 resulted in the formation of a new class of compounds, the 2-arylseleno-2-chloro-1,2,3-triorgano-1,3,2λ5-diazaphosphetidin-4-ones 14–19 . The new selenophosphoranes 20 and 21 were obtained in the reaction of 15 and 17 with p-nitrophenol in the presence of triethylamine. The identity and structure of the new compounds were established by 1H- and 13C-NMR spectroscopy, elemental analysis, 31P- and 77Se-NMR spectroscopy in the case of the selenophosphoranes 14–21 , and mass spectrometry in the case of 11 and 13 . A possible mechanism of the reaction leading to the selenophosphoranes is discussed. Single-crystal X-ray structure analyses of the selenophosphoranes 19 and 20 were conducted. Both display distorted trigonal bipyramidal geometry at phosphorus, the major distortions being imposed by the four-membered rings. 相似文献
The syndiotactic polymerization of styrene with exo-[(η5-isodiCp)TiCl3] 1/methylalumoxane (MAO; isodiCp=isodicyclopentadienyl) was studied as well as the ethylene/styrene copolymerization with exo-[{η5:η1(N)-isodiCp(SiMe2Nt-Bu)}TiCl2] 2/MAO. These two catalytic systems are stable during polymerization. The half-sandwich titanocene 1 exhibits good syndiospecificity and average activity. The bridged half-sandwich amino complex 2 was found to incorporate styrene into polymer chains at 70 °C. Activity results decrease with increasing styrene concentrations. 相似文献