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E. Campaigne K. Folting J. C. Huffman T. P. Selby 《Journal of heterocyclic chemistry》1981,18(3):575-580
Ethyl 4-chloroacetoacetate condenses with 4-amino-6-hydroxy-2-pyrimidinethiol to yield ethyl 3-hydroxy-5-oxo-7-aminothiazolino[3,2-a]pyrimidin-3-acetate ( 3 ), and not ethyl 3-hydroxy-5-amino-7-oxothiazolino[3,2-a]-pyrimidin-3-acetate, as previously reported. This compound reacts with ammonia to produce ethyl 4-(6′-amino-4′-oxo-2′-pyrimidinethiol)-3-aminocrotonate ( 8 ), the open chain structure of which accounts for the cyclization of 3 to the poly-cyclic lactam, 6a-hydroxy-5,6,6a,7-tetrahydro-8-thia-1,4-diazacycl[3.3.2]azine-2,5-dione, rather than the sterically more favorable lactone, when 3 was treated with triethylamine. Some other reactions of 3 are described, and the structures of 3 and 8 were comfirmed by single crystal X-ray diffraction analysis. 相似文献
125.
Dennett JN Knox SA Anderson KM Charmant JP Orpen AG 《Dalton transactions (Cambridge, England : 2003)》2005,(1):63-73
The synthesis, fluxionality and reactivity of the heterobimetallic complex [FeRu(CO)2(mu-CO)2(eta-C5H5)(eta-C5Me5)] are described. Complex exhibits enhanced photolytic reactivity towards alkynes compared to its homometallic analogues, forming the dimetallacyclopentenone complexes [FeRu(CO)(mu-CO){mu-eta]1:eta3-C(O)CR"CR'}eta]-C5H5)(eta-C5Me5)]( R'= R"= H; R'= R"= CO2Me; R'= H, R"= CMe2OH). Prolonged photolysis with diphenylethyne gives the dimetallatetrahedrane complex [FeRu(mu-CO)(mu-eta2:eta2-CPhCPh)(eta-C5H5)(eta-C5Me5)], which contains the first iron-ruthenium double bond. Complexes containing a number of organic fragments can be synthesised using , and . Heating a solution of gave the alkenylidene complex [FeRu(CO)2(mu-CO){mu-eta]1:eta2-C=C(CO2Me)2}(eta-C5H5)(eta-C5Me5)] through an unusual methylcarboxylate migration. Protonation and then addition of hydride to gives the ethylidene complex [FeRu(CO)2(mu-CO)(mu-CHCH3)(eta-C5H5)(eta-C5Me5)] via the ionic vinyl species [FeRu(CO)2(mu-CO)(mu-eta]1:eta2-CH=CH2)(eta-C5H5)(eta-C5Me5)][BF4]. Compound exhibits cis/trans isomerisation at room temperature. Protonation of dimetallacyclopentenone complexes gives the allenyl species [FeRu(CO)2(mu-CO)(mu-eta1:eta2-CH=C=CMe2)(eta-C5H5)(eta-C5Me5)][BF4]. Compound exist as three isomers, two cis and one trans. The two cis isomers are shown to be interconverting by sigma-pi isomerisation. The solid state structures of these compounds were established by X-ray crystallography and are discussed. 相似文献
126.
David L. Davies Andrew F. Dyke Andreas Endesfelder Selby A.R. Knox Pamela J. Naish A. Guy Orpen Dietrich Plaas Graham E. Taylor 《Journal of organometallic chemistry》1980,198(2):C43-C49
The ethyne-derived demetallocycle [Ru2(CO) (μ-CO){μ-C(O)C2H2}(η-C5H5)2 isomerises in boiling toluene to yield the μ-vinylidene complex [Ru2(CO)2(μ-CO)(μ-CCH2) (η-C5H5)2], which on protonation with dry HBF4 provides the μ-carbyne complex [Ru2(CO)2(μ-CO)(μ-CCH3)(η-C5H5)2][BF4]; the structure of each product has been determined by X-ray diffraction. The μ-carbyne cation is attacked by hydride to produce the μ-methylcarbene complex [Ru2(CO)2(μ-CO)(μ-CHCH3)(η-C5H5)2]. 相似文献
127.
David L. Davies Judith A.K. Howard Selby A.R. Knox Karen Marsden Kevin A. Mead Michael J. Morris Melvyn C. Rendle 《Journal of organometallic chemistry》1985,279(3):c38-c41
The complexes [Ru2(CO)2(μ-CO)(μ-CMe)(η-C5H5)2]? and [Ru2CO2(μ-CO)(μ-CCH2)(η-C5H5)2] react together to give [{Ru2CO)3(η-C5H5)2}2(μ-CMeCHCH)]+ and [{Ru3(CO)3(η-C5H5)3}(μ-CCH2CHC){Ru2(CO)3(η-C5H5)2}], each characterised by X-ray diffraction. The former results from ethylidyne-vinylidene linking followed by an alkylidyne to vinyl rearrangement. 相似文献
128.
A magnetized Iron CALorimeter (ICAL) detector at the India-based neutrino observatory (INO) is used to study neutrino oscillation sensitivity using atmospheric muon neutrino source. The ICAL detector will be able to detect muon tracks and hadron showers produced by neutrino interactions with the iron target. We have performed precision measurement analysis for the atmospheric neutrino oscillation parameters with the muon neutrino events, generated by Monte Carlo NUANCE event generator. A marginalized χ2 analysis based on reconstructed neutrino energy and muon zenith angle binning scheme has been performed to determine the sensitivity for the atmospheric neutrino mixing parameters, \(\sin ^{2}\theta _{23}\) and \(| {\Delta } m^{2}_{23}|\). 相似文献
129.
Selby JD Schulten C Schwarz AD Stasch A Clot E Jones C Mountford P 《Chemical communications (Cambridge, England)》2008,(41):5101-5103
The first structurally authenticated [2+2] cycloaddition products of any transition metal hydrazide complexes are reported; cycloaddition products of transition metal hydrazides with alkynes and heteroalkynes have been obtained for the first time; these are the first structurally authenticated cycloaddition products for any transition metal M=NNR(2) functional group. 相似文献
130.
Hayes CJ Sherlock AE Green MP Wilson C Blake AJ Selby MD Prodger JC 《The Journal of organic chemistry》2008,73(6):2041-2051
An alkylidene carbene 1,5-CH insertion has been used as a key step in an enantioselective total syntheses of omuralide, its C7-epimer, and (+)-lactacystin. An additional noteworthy feature of the synthesis is the use of a novel oxidative deprotection procedure, utilizing DMDO, for the conversion of a late-stage benzylidene acetal into a primary alcohol and a secondary benzoate ester. 相似文献