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A. V. Anisimov G. N. Murina L. V. Mozhaeva N. B. Kazennova E. A. Viktorova 《Chemistry of Heterocyclic Compounds》1984,20(6):599-601
The direction of the reaction of alkyl furfuryl ethers and sulfides with n-butyllithium is in agreement with the results of basic H-D exchange in the same compounds: In the case of the ethers H-D exchange and metallation take place primarily in the free a position of the furan ring, whereas in the case of the sulfides these reactions take place primarily at the methylene group of the side chain located between the sulfur atom and the furan ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 744–746, June, 1984. 相似文献
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The Ag+ induced reaction of α-chloronitrones with unsaturated ethers goes in two parallel competitive directions. On the one hand cycloadducts like 3 are formed and on the other hand oxonium ions like 4. Formation of analogous oxonium compounds occurs also when α-alkoxynitrones are treated with Et3O+BF4? in 1,2-dichloroethane. Formation of oxonium compounds with the enol-ethers is practically irreversible and leads to enol-ether fragmentation. With the saturated ethers compounds like 25 were formed and were used as a potential source of N-alkyl-N-vinyl-nitrosonium ions. 相似文献
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N-Aminophthalimide (I) reacted with a variety of aromatic aldehydes to give the related arylideneaminophthalimides (III-X), although typical ketones such as acetone and benzophenone did not under the specific conditions employed. Catalytic reduction of benzylideneaminophthalimide (III) led to N-benzylaminophthalimide (XI), a stable acid-free precursor of benzylhydrazine. 相似文献
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Pellissier A Bretonnière Y Chatterton N Pécaut J Delangle P Mazzanti M 《Inorganic chemistry》2007,46(9):3714-3725
The crystal and molecular structure and the stability of lead and calcium complexes of two chelates containing picolinate chelating groups in different geometries have been investigated in order to relate the ligand affinity and selectivity for lead over calcium with the ability of the ligand to accommodate a stereochemically active lone pair. The crystal structures of the lead complexes of the diprotonated and monoprotonated tripodal ligand tpaa2- show that the three picolinate arms of the tripodal ligand coordinate the lead in an asymmetric way leaving a gap in the coordination sphere to accommodate the lead lone pair. As a consequence of this binding mode, one picolinate arm is very weakly bound and therefore can be expected to contribute very little to the complex stability. Conversely, the geometry of the dipodal ligand H2dpaea is designed to accommodate the lead lone pair; in the structure of the [Pb(dpaea)] complex the donor atoms of the ligand occupy only a quarter of the coordination sphere, reducing the sterical interaction between the lead lone pair with respect to the H3tpaa complexes. As a result, in the lead structures of H2dpaea all the ligand donor atoms are strongly bound to the metal ion leading to increased stability. The high value of the formation constant measured for the lead complex of the dipodal dpaea2- (log beta11(Pb)=12.1(3)) compared to the lower value found for the one of the tripodal tpaa3- (log beta11(Pb)=10.0(1)) provides direct evidence of the influence of the stereochemically active lead lone pair on complex stability. As a result, since the ligand geometry has little effect on the stability of the calcium complex, a remarkable increase in the Pb/Ca selectivity is observed for dpaea-(10(6.6)) compared to tpaa3- (10(1.5)), making the dipodal ligand a good candidate for application as extracting agent for the lead removal from contaminated water. 相似文献
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Vladimir A. Potapov 《Tetrahedron letters》2011,52(36):4606-4610
Highly chemo-, regio-, and stereoselective syntheses of novel organoselenium compounds from selenium dichloride or dibromide and unsaturated ethers are described. The reactions of selenium dichloride with allyl and propargyl phenyl ethers afford either annulated products or bis-adducts depending on the conditions. The first examples of annulation of 3-chloromethyl- and 3-chloromethylene-2,3-dihydro-1,4-oxaselenine to the benzene ring are reported. 相似文献
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Conclusions Electron transfer from the reducing agent to the complex occurs when the electron donors, sodionaphthalene and sodiomalonic ester, act on (1,5-cyclooctadiene)duroquinonenickel, with the formation of the [(C8H12)(DQ)Ni]–· anion radicals, which proved to be thermally less stable and more reactive than the anion radicals of bis(duroquinone)nickel.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2320–2322, October, 1975. 相似文献
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Conclusions Two-component catalysts based on Pd(acac)2 or PdCl2 and Ph2P permit one to carry out the regioselective cross- coup ling of isoprenylmagnesium bromide with allyl ethers and esters, allyl halogenides, involving the simultaneous insertion of elemental sulfur into the metal-carbon bond, which results in the formation of higher order allyl sulfides, which are not easily accessible (by other means).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 410–413, February, 1987.The authors thank A. A. Panasenko and R. R. Muslukhova for help in interpreting the13C-NMR spectra. 相似文献
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Swor CD Hanson KR Zakharov LN Tyler DR 《Dalton transactions (Cambridge, England : 2003)》2011,40(34):8604-8610
Non-coordinated hydroxymethylphosphines react readily with primary and secondary amines by the phosphorus Mannich reaction. To determine if this reactivity can be used to synthesize phosphine macrocycles, trans-Fe(DHMPE)(2)Cl(2) (DHMPE = 1,2-bis(dihydroxymethylphosphino)ethane) was prepared and reacted with various amines. However, no phosphorus Mannich reactivity was observed. In order to understand why no reactions occurred, the Mannich reactivity of the borane-coordinated hydroxymethylphosphines DHMPE·2BH(3) and Ph(2)PCH(2)OH·BH(3) was investigated. These borane-coordinated phosphines also did not undergo the phosphorus Mannich reaction. These results suggest that the lone pair of electrons on the phosphorus atom is essential for the phosphorus Mannich reaction to occur, and therefore it is not possible to use this reaction in a templated synthesis of phosphine macrocycles. It is speculated that the mechanism of the phosphorus Mannich reaction may involve a methylenephosphonium intermediate, analogous to an iminium in the standard Mannich reaction. X-ray crystal structures of trans-Fe(DHMPE)(2)Cl(2) and DHMPE·2BH(3) are also presented. Both crystal structures display an extended hydrogen-bonding network in the solid state. 相似文献
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Summary A study was made of regularities observed in the copolymerization of various vinyl sulfides with various other monomers; the copolymers were isolated, and their properties were studied. 相似文献
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Wataru Ando Toshiya Furuhata Yukio Hanyu Toshikazu Takata 《Tetrahedron letters》1984,25(36):4011-4014
A variety of sulfur-containing five- and six-membered cyclic compounds was obtained by the acid-catalyzed and thermal reactions of an allene episulfide with various electrophiles. 相似文献
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Dimethyl acetylenedicarboxylate reacts with 7-dehydrocholesteryl acetate (I) by nucleophilic addition at C7. Two products are obtained, resulting from subsequent hydrogen abstraction from C9 (II) and from C14 (III) respectively. Addition-abstraction, hitherto unreported for esters of acetylenedicarboxylic acid, appears to be the sole reaction mode with this highly hindered diene-system. Structure proof is supported by NMR spectroscopy as well as by chemical transformations of the adducts. On treatment with base one of the adducts undergoes a prototropic rearrangement. 相似文献
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O. N. Nuretdinova 《Russian Chemical Bulletin》1965,14(10):1871-1872
Summary A study was made of the addition of the ethyl- and phenyldichlorophosphines to propylene sulfide and of phosphenyl chloride to ethylene sulfide. 相似文献
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Carbonation of the parent cyclononatetraene dianion gives a mixture of (a) the minor products, 1,3,6-cyclononatriene-5,9- and 5,8-dicarboxylic acids, and (b) the major product, bis(5-carboxy-1,3,6-cyclononatrien-9-yl). In contrast, the 9,9-dimethyl dianion affords almost entirely a mixture of the two monocyclic diacids. Similar results are obtained on trimethylsilylation. Conformations of the products are discussed. 相似文献