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1.
Qibo Liu 《Journal of fluorine chemistry》2010,131(11):1082-1085
Chlorotrifluoroethene is converted in situ to [F2CCFSiMe3]. The crude [F2CCFSiMe3] solution is reduced with lithium aluminum hydride to (HFCCFSiMe3), which (without isolation) is converted to (Z)-HFCCFSnBu3. Subsequent metallation and trapping of the vinyllithium reagent with Bu3SnCl gives (E)-Bu3SnCFCFSnBu3 in 73% overall yield. Only two isolation steps are required and the use of Me3SiCl and F2CCFCl provides a cheap, economical route to this useful synthon. 相似文献
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Qibo Liu 《Journal of fluorine chemistry》2011,132(2):78-87
(Z)-HFCCFZnI was stereoselectively synthesized from activated zinc dust and (Z)-HFCCFI that was synthesized from chlorotrifluoroethene in a sequential manner. Compared to (E)-HFCCFZnI, (Z)-HFCCFZnI was more challenging to prepare in terms of sluggish metallation and formation of by-products, and underwent slower and incomplete Negishi coupling with aryl iodides. In a modification of Negishi coupling, (E)-α,β-difluorostyrenes were stereospecifically prepared in good to excellent yields under mild conditions from aryl iodides and (Z)-HFCCFZnI with the co-catalysis of Pd(PPh3)4/Cu(I)Br. Experimental investigation and mechanistic rationalization suggested that Cu(I)Br would be a scavenger of free ligands for the facilitation of Pd(PPh3)2 formation, and a supplier of ligand for the metathesis process. Alternatively, (Z)-HFCCFSnBu3 and aryl iodides with an electron-withdrawing group underwent Stille-Liebiskind coupling to afford (E)-α,β-difluorostyrenes. 相似文献
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Dilip K. Sinha-Mahapatra Vedavati G. Puranik 《Journal of organometallic chemistry》2004,689(22):3501-3512
Addition of PhSH-NEt3 or PhSeNa to PhCCC(OC2H5)M(CO)5 [M = Cr or W] afforded stable, β-chalcogenide tethered conjugated carbene complexes 3-6 as a mixture of E,Z-isomers. The Z-configuration was ascribed to those isomers that readily yield cyclometallated complexes. Aminolysis with methylamine yielded corresponding amino carbene complexes as mixtures of E,Z-isomers. Alkylation by methyl iodide afforded separable E,Z-isomers of dimethylamino complexes. One-step aminolysis of ethoxy carbene complexes with dimethylamine furnished only the Z-isomer of the dimethylamino complex. The Z-isomer of dimethylamino carbene complexes yielded cyclometallated products on warming. Representative crystal structures of these complexes confirm isomer assignments. Only E-isomers of the S or Se-tethered ethoxy complexes undergo benzannulation reaction with alkynes, with loss of chalcogenide atom. 相似文献
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Treatment of RuHCl(CO)(PPh3)3 with (3E,5E,7E,9E,11E)-HCC-(CHCH)5- CCH produces [RuCl(CO)(PPh3)2]2[μ-(CHCH)7]. The later complex reacts with PMe3 to give [RuCl(CO)(PMe3)3]2[μ-(CHCH)7], the structure of which has been confirmed by X-ray diffraction. The through-space distance from one Ru to the other is 19.88 Å. 相似文献
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Michael I. Bruce Benjamin G. Ellis Allan H. White 《Journal of organometallic chemistry》2005,690(3):792-801
Whereas {Ru(dppm)Cp*}2(μ-CCCC) (2) is the only product formed by deprotonation of [{Ru(dppm)Cp*}2{μ(CCHCHC)}]+ with dbu, a mixture of 2 with Ru{CCCHCH(PPh2)2[RuCp*]}(dppm)Cp* (3) and {Cp*Ru(PPh2CHCCH-)}2 (4) is obtained with KOBut. A similar reaction with [{Ru(dppm)Cp*}2{μ(CCMeCMeC)}]+ (5) gave Ru{CCCMeCH(PPh2)2[RuCp*]}(dppm)Cp* (6). X-ray structures of 4, 5 and 6 confirm the presence of the 1-ruthena-2,4-diphosphabicyclo[1.1.1]pentane moiety, which is likely formed by an intramolecular attack of the deprotonated dppm ligand on C(1) of the vinylidene ligand. Protonation of {Ru(dppe)Cp*}2(μ-CCCC) (8-Ru) regenerates its precursor [{Ru(dppe)Cp*}2{μ(CCHCHC)}]2+ (7-Ru). Ready oxidation of the bis(vinylidene) complex affords the cationic carbonyl [Ru(CO)(dppe)Cp*]PF6 (9) (X-ray structure). 相似文献
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The alkenylaminoallenylidene complex [Ru(η5-C9H7){CCC(NEt2)[C(Me)CPh2]}{κ(P)-Ph2PCH2CHCH2}(PPh3)][PF6] (2) has been prepared by the reaction of the allenylidene [Ru(η5-C9H7)(CCCPh2){κ(P)-Ph2PCH2CHCH2}(PPh3)][PF6] (1) with the ynamine MeCCNEt2. The reaction proceeds regio- and stereoselectively, and the insertion of the ynamine takes place exclusively at the CβCγ bond of the unsaturated chain. The secondary allenylidene [Ru(η5-C9H7){CCC(H)[C(Me)CPh2]}{κ(P)-Ph2PCH2CHCH2}(PPh3)][PF6] (3) is obtained, in a one-pot synthesis, from the reaction of aminoallenylidene 2 with LiBHEt3 and subsequent treatment with silica. Moreover, the addition of an excess of NaBH4 to a solution of the complex 2 in THF at room temperature gives exclusively the alkynyl complex [Ru(η5-C9H7){CCCH2[C(Me)CPh2]}{κ(P)-Ph2PCH2CHCH2}(PPh3)] (5). The heating of a solution of allenylidene derivative 3 in THF at reflux gives regio- and diastereoselectively the cyclobutylidene complex [Ru(η5-C9H7) (PPh3)][PF6](4) through an intramolecular cycloaddition of the CC allyl and the CαCβ bonds in the allenylidene complex 3. The structure of complex 4 has been determined by single crystal X-ray diffraction analysis. 相似文献
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Thomas Haas 《Journal of organometallic chemistry》2011,696(4):946-955
Copper-catalyzed reaction of [Cp(PPh3)NiCl] with the terminal alkynes H-CC-C(O)R (R = O-Menthyl, NMe2, Ph) yields the alkynyl complexes [Cp(PPh3)Ni-CC-C(O)R]. Subsequent O-methylation with either [Me3O]BF4 or MeSO3CF3 affords cationic allenylidene complexes, [Cp(PPh3)NiCCC(OMe)R]+X¯ (X = BF4, SO3CF3). N-Alkylation of Cp(PPh3)Ni-pyridylethynyl complexes likewise gives cationic allenylidene complexes. [Cp(PPh3)Ni-CC-C(CH)4N] adds BF3 at nitrogen. Modification of the ligand sphere in these nickel allenylidene complexes is possible by replacing PPh3 by PMe3 in the alkynyl complex precursors. The first allenylidene(carbene)nickel cation, [Cp(SIMes)NCCC(OMe)NMe2]+, is accessible by successive reaction of [Cp(SIMes)NiCl] with H-CC-C(O)NMe2 and [Me3O]BF4. By the analogous sequence an allenylidene complex containing the chelating (diphenylphosphanyl)ethylcyclopentadienyl ligand can be prepared. DFT Calculations were carried out on the allenylidene complex cation [Cp(PPh3)NiCCC(OMe)NMe2]+ and on its precursor, the alkynyl complex [Cp(PPh3)Ni-CC-C(O)NMe2]. Based on the spectroscopic data and a X-ray structure analysis the bonding in the new nickel allenylidene complexes is best represented by several resonance forms, an alkynyl resonance form considerably contributing to the overall bond. 相似文献
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Fang Liu 《Journal of organometallic chemistry》2010,695(6):809-3960
A series of heterobinuclear ferrocene-ruthenium complexes Fc(CHCH)nRuCl(CO)(PMe3)3 (n = 1, 3; n = 2, 12), Fc(CHCH)RuCl(CO)(Py)(PPh3)2 (4), and trimetallic Fc(CHCH)RuCl(CO)(PPh3)2(Py-E-(CHCH)Fc) (6) have been prepared. The length of the molecular rods is extended by successive insertion of CHCH spacers in the bridging ligands or the ancillary ligands. The respective products have been fully characterized and the structures of 3 and 12 have been established by X-ray crystallography. Electrochemical studies have revealed that ethenyl heterobimetallic complexes display two successive one-electron processes, and that intermetallic electronic communication between the two endgroups is attenuated with the increase of the length of the conjugated bridge. The electrochemical behavior of the trimetallic complex reveals strong electronic communication between ruthenium and ferrocene transmitted through the ethenyl bridge, however, it also reveals a very weak interaction between ruthenium and ferrocene transmitted through the (E)-CHCH-Py bridge. 相似文献
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Kamil I. Utegenov 《Journal of organometallic chemistry》2011,696(21):3408-3414
The addition of phosphines to the manganese allenylidene complexes Cp(CO)2MnCCC(Ph)R (R = H, Ph) proceeds selectively at the Cα atom to result in the α-phosphonioallenyl complexes Cp(CO)2Mn−-C(+PR31)CC(Ph)R. The protonation of the latter affords the η2-(1,2)-phosphonioallenes Cp(CO)2Mn{η2-(1,2)-HC(+PR31)CC(Ph)R}, rather than the phosphoniovinylcarbenes Cp(CO)2MnC(+PR31)-HCC(Ph)R. All complexes obtained are stereochemically rigid and do not isomerize into the η2-(2,3)-phosphonioallene isomers. 相似文献
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The synthesis of the new ruthenium(II) allenylidene complex [ClRu(dppe)2CCC11H6N2][OTf] (4) (dppe = 1,2-bis(diphenylphosphino)ethane) terminated with a 4,5-diazafluorene ligand is reported. Further coordination of that metal allenylidene to ruthenium and rhenium moieties leads to the bimetallic adducts [ClRu(dppe)2CCC11H6N2{Ru(bpy)2}][B(C6F5)4]3 (5a), [ClRu(dppe)2CCC11H6N2{Ru(tBu-bpy)2}][PF6]3 (5b) and [ClRu(dppe)2CCC11H6N2{Re(CO)3Cl}][OTf] (6). Their optical and electrochemical properties show that the allenylidene moiety is an attractive molecular clip for the access to larger original redox-active homo/heteronuclear multi-component supramolecular assemblies. The X-ray crystal structure of the allenylidene metal building block is also described. 相似文献
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Isao Yamaguchi Ayaka Kado Hiroki Fukumoto Moriyuki Sato 《European Polymer Journal》2010,46(5):1119-1130
Reactions of N-(2,4-dinitrophenyl)-4-arylpyridinium chlorides (aryl (Ar) = phenyl and 4-pyridyl) with piperazines caused the ring opening of the pyridinium ring and yielded polymers that consisted of 5-piperazinium-3-aryl-penta-2,4-dienylideneammonium chloride units [N(CH(R)CH2)2N+(Cl−)CHCHC(Ar)CHCH, RH, Me, and phenyl]. However, the same reactions occurring in the presence of piperidine yielded oligomers that consisted of 5-piperazinium-3-aryl-penta-2,4-dienylideneammonium chloride units having piperidine and/or piperazine rings at both ends. 1H NMR spectra suggested that π-electrons of the penta-2,4-dienylideneammonium group of the polymers and the oligomers were delocalized. UV-vis measurements revealed that the π-conjugation system expanded along the polymer and oligomer chains due to the orbital interaction between electrons on the two nitrogen atoms of the piperazinium ring. Conversion of the piperazinium ring from the boat form to the chair form caused decrease in the π-conjugation length. The rate constants of the conversion of the oligomers depended on their chain lengths. The surface of pellets that were molded from the polymers and oligomers exhibited metallic luster. These polymers and oligomers underwent electrochemical oxidation in solution. 相似文献
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Matthias Drexler 《Journal of organometallic chemistry》2005,690(16):3700-3713
Pentacarbonyl dimethylamino(methoxy)allenylidene tungsten, [(CO)5WCCC(OMe)NMe2] (1b), reacts with one equivalent of primary amines, H2NR, by selectively replacing the methoxy group to give dimethylamino(amino)allenylidene complexes, [(CO)5WCCC(NHR)NMe2]. When the amine is used in excess both terminal groups, OMe as well as NMe2, are replaced by the primary amino group giving [(CO)5WCCC(NHR)2 ]. The NHR substituent in these complexes may be modified by deprotonation with LDA followed by alkylation. The replacement of the methoxy group in 1b by a secondary amino group, NR2, can be achieved by a stepwise process. Addition of Li[NR2] to the Cγ atom of 1b affords an alkynyl tungstate. Subsequent OMe− elimination induced by TMS-Cl/SiO2 yields the allenylidene complexes [(CO)5WCCC(NR2)NMe2]. When bidentate diamines are used instead of monoamines both substituents, OMe and NMe2, are replaced and allenylidene complexes are formed in which Cγ constitutes part of a 5-, 6-, or 7-membered heterocycle. The reaction of [(CO)5CrCCC(OMe)NMe2] (1a) with diethylene triamine affords an allenylidene complex with a heterocyclic endgroup carrying a dangling CH2CH2NH2 substituent. All reactions follow a strict regioselective attack of the nucleophile at Cγ and proceed with good to excellent yields. The addition of N-H to the CαCβ bond is not observed. By applying either one of these routes nearly any substitution pattern in bis(amino)allenylidene complex can be realized. 相似文献
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Lise Baiget Jean Escudié Gabriela Cretiu Nemes Luminita Silaghi-Dumitrescu 《Journal of organometallic chemistry》2005,690(2):307-312
Dechlorofluorination of ArSb(F)-C(Cl)CR2 (CR2 = fluorenylidene, Ar = 2,4,6-tri-tert-butylphenyl) by tert-butyllithium afforded a 3,4-bis(fluorenylidene)-1,2-distibacyclobutane. The formation of the latter probably involves the transient stibaallene ArSbCCR2 followed by a head-to-head dimerization via two SbC double bonds. Molecular orbital calculations at the ab initio and DFT levels support the head-to-head dimerization of ArSbCCR2 with the formation of a 1,2-distibacyclobutane. 相似文献
18.
Guangwei Wang 《Tetrahedron letters》2009,50(26):3220-11349
In situ OH metalation with iBu2AlH and hydrozirconation with HZrCp2Cl of HOCH2CCH, (E)-HOCH2CHCHCCH, and HOCH2CCCH3 followed by Pd-catalyzed alkenyl-alkenyl coupling with (E)-BrCHCHCO2Et and (E)-BrCHC(Me)CO2Et using PEPPSI-IPr (7) as a catalyst provides a highly efficient and selective (?98% all-E) route to ω-hydroxy di- and trienoic acid esters (1a-6a). The corresponding phosphonate esters (1c-4c) of ?98% isomeric purity can be obtained via conventional bromination-phosphonation in >80% yields. As expected, their carbonyl olefination is ca. 85-90% E-selective with alkyl aldehydes but ?98% E-selective with PhCHO and some α,β-unsaturated aldehydes under the conditions used. 相似文献
19.
David J. Armitt Jonathan C. Morris Allan H. White 《Journal of organometallic chemistry》2009,694(1):1-8561
In contrast to the usual formal [2+2]-cycloaddition reaction, (NC)2CC{CC(SiPri3)}2, containing bulky alkynyl substituents, reacts with Ru(CCPh)(PPh3)2Cp to give the unprecedented cyclobutenylidene complex Ru{C(CN)2C[CC(SiPri3)]CC(SiPri3)CPhC}(PPh3)Cp, formed by addition of one of the CC(SiPri3) groups to the Ru-CCPh moiety and subsequent electronic reorganisation. 相似文献
20.
Christopher M. Timperley Matthew J. Waters Jackie A. Greenall 《Journal of fluorine chemistry》2006,127(2):249-256
Reactions of perfluoroisobutene (PFIB), perfluoropropene (PFP) and chlorotrifluoroethene (CTFE) with benzenethiol and 2-methoxybenzenethiol in acetonitrile, with potassium carbonate as base, were compared. PFIB reacted with benzenethiol to give ketene thioacetal (CF3)2CC(SAr)2 and with 2-methoxybenzenethiol to give mono- and bis-vinyl species (CF3)2CCFSAr and (CF3)2CC(SAr)2. PFP reacted with both thiols to give the addition product CF3CFHCF2SAr and vinyl isomers CF3CFCFSAr (6:1 E/Z ratio). CTFE reacted with several methoxy-substituted arylthiols to give addition products of structure CFClHCF2SAr. The arylthiols used throughout the study imitate biological thiols. Inhalation toxicities of the fluoroalkenes decrease in the order PFIB > PFP > CTFE and correlate with their reactivities towards the model thiols, supporting the current view that their toxicity relates to their ability to react with biological thiols. 相似文献