共查询到20条相似文献,搜索用时 31 毫秒
1.
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
2.
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
3.
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
4.
Jun Yin 《Journal of organometallic chemistry》2005,690(19):4265-4271
A versatile synthetic route to conjugated bimetallic ruthenium complexes with σ,σ-bridging azobenzene chains was developed, and new ruthenium complexes with various ligands were synthesized and characterized. These bimetallic complexes showed a remarkable absorption in the visible region (λmax: 452-483 nm), and undergo trans-to-cis isomerization under UV light irradiation for short time. Electrochemical study showed that the metal centers in bimetallic complexes containing the CHCHC6H4NNC6H4CHCH bridge interact with each other. 相似文献
5.
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
6.
Bror J. Wik 《Journal of organometallic chemistry》2007,692(15):3223-3230
The oxidation of the Pt(IV) tetramethyl complex [ArNCHCHNAr]PtMe4 (Ar = 2,6-Me2C6H3) has been investigated in acetonitrile and dichloromethane. Cyclic voltammetry demonstrates that the irreversible oxidation of [ArNCHCHNAr]PtMe4 occurs at a slightly less positive oxidation potential than the irreversible oxidation of the analogous Pt(II) species [ArNCHCHNAr]PtMe2. The product distribution arising from the oxidation depends strongly on the reaction conditions and includes cationic Pt(IV) species (acetonitrile, dichloromethane solvents) and Pt(II) species (dichloromethane only). Evidence is presented that suggests that homolytic cleavage of a weakened PtC bond in is involved in the oxidatively induced reactions. 相似文献
7.
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
8.
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
9.
Michael I. Bruce Benjamin G. Ellis Allan H. White 《Journal of organometallic chemistry》2005,690(7):1772-1783
Several complexes have been obtained from reactions carried out in early attempts to prepare the diynyl complexes Ru(CCCCR)(dppe)Cp* (R = H, SiMe3). These have been identified crystallographically as the acyl complex Ru{CCC(O)Me}(dppe)Cp* (3), the cationic imido complex [Ru{CCC(NH2)Me}(dppe)Cp*]PF6 (4), the binuclear butenynylallenylidene [{Ru(dppe)Cp*}2{μ-CCC(OMe)CHCMeCC}]PF6 (5), and the bis(ethynyl)cyclobutenylidene [{Ru(dppe)Cp*}2{μ-CCC4H2(SiMe3)CC}]PF6 (6). NMR studies of 5 have revealed the existence of two isomers. Plausible routes for their formation from the putative butatrienylidene intermediate [Ru(CCCCH2)(dppe)Cp*]+ (A) are discussed. 相似文献
10.
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
11.
12.
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
13.
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
14.
Jason M. Lynam Tracy D. Nixon Adrian C. Whitwood 《Journal of organometallic chemistry》2008,693(19):3103-3110
Reaction of cis-[RuCl2(dppm)2] (dppm = 1,2-bis(diphenylphosphino)methane) with PhCCH and NaPF6 utilising methanol as solvent results in the formation of the η3-butenynyl complex [Ru(η3-PhCCCCHPh)(dppm)2][PF6] in good yield. Similar reactions with ButCCH and PrnCCH resulted in the corresponding alkyl-substituted complexes and all three of these compounds have been characterised by NMR spectroscopy and X-ray crystallography. The mechanism of this reaction has been probed by employing labelling experiments with both PhCCD and PhC13CH allowing the identity of possible intermediates in the reaction to be determined. Furthermore, [Ru(η3-PhCCCCHPh)(dppm)2][PF6] has been shown to be an effective regio- and stereo-selective catalyst for the dimerisation of PhCCH to Z-PhCCCHCHPh in the absence of solvent. In contrast, no evidence for the formation of alkyne coupling was obtained from the reaction of cis-[RuCl2(dppe)2] (dppe = 1,2-bis(diphenylphosphino)ethane) with PhCCH and NaPF6. 相似文献
15.
Robert J. Angelici 《Journal of organometallic chemistry》2008,693(5):847-856
As in transition metal complexes, CN-R ligands adsorbed on powdered gold undergo attack by amines to give putative diaminocarbene groups on the gold surface. This reaction forms the basis for the discovery of a gold metal-catalyzed reaction of CN-R, primary amines (R′NH2) and O2 to give carbodiimides (R′-NCN-R). An analogous reaction of CO, RNH2, and O2 gives isocyanates (R-NCO), which react with additional amine to give urea (RNH)2CO products. The gold-catalyzed reaction of CN-R with secondary amines (HNR′2) and O2 gives mixed ureas RNH(CO)NR′2. In another type of gold-catalyzed reaction, secondary amines HN(CH2R)2 react with O2 to undergo dehydrogenation to the imine product, RCHN(CH2R). Of special interest is the high catalytic activity of gold powder, which is otherwise well-known for its poor catalytic properties. 相似文献
16.
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
17.
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
18.
The Perkow reaction of triethyl phosphite and β-alkoxyvinyl trihalogenomethyl ketones, which have common acyclic or cyclic structural fragment: -O-CC-C(O)CX2Cl, yielded dienyl phosphates: -O-CC-C[OP(O)(OEt)2]CX2 where X = F or Cl, whereas γ-bromo-β-methoxy-α,β-unsaturated trifluoromethyl ketone CF3C(O)CHC(OMe)CH2Br gave diene CF3C[OP(O)(OEt)2]CH-C(OMe)CH2. 相似文献
19.
The new ferrole Fe2(CO)6[μ-η2,η4-(Fc)CC{C(H)C(R)S}CC(SiMe3)] [R = SiMe3 (1) and R = Fc (2)] and ruthenoles Ru2(CO)6[μ-η2,η4-(Me3Si)CC{SC(Fc)C(H)}CC(Fc)] 3 and Ru2(CO)6[μ-η2,η4-(Me3Si)CC(SCCFc)C(H)C(Fc)] 4, have been obtained from the reactions of M3(CO)12 (M = Fe, Ru) and FcCCSCCSiMe3 through S-C bond activations and C-C coupling reactions. Thermolysis of Ru2(CO)6[μ3-η2,η4,η3-(Me3Si)CC{SC(Fc)C(SCCSiMe3}Ru(CO)3}CC(Fc)] alone and in the presence of HCCFc, yielded the compounds Ru2(CO)6[μ-η2,η4-(Me3Si)CC{SC(Fc)C(SCCSiMe3)}CC(Fc)] 5 and Ru2(CO)6[μ-η2,η4-(Me3Si)CC{SC(Fc)C(SCCSiMe3)C(H)C(Fc)}CC(Fc)] 6, respectively. The crystal structures of the compounds 1, 3, 4 and 6 are reported. 相似文献
20.
Michael I. Bruce Martyn Jevric Wyona Patalinghug Brian W. Skelton Natasha N. Zaitseva 《Journal of organometallic chemistry》2008,693(17):2915-2920
Addition of [I(py)2]BF4 to Ru(CCH)(dppe)Cp∗ gave the iodovinylidene [Ru(CCHI)(dppe)Cp∗]BF41, which could be deprotonated to Ru(CCI)(dppe)Cp∗ 2. The attempted preparation of Ru(CCCCI)(dppe)Cp∗, followed by derivatisation with tcne, gave the dienynyl Ru{CCC[C(CN)2]CIC(CN)2}(dppe)Cp∗ 3. The Pd(0)/Cu(I)-catalysed reaction of 3 with Ru{CCCCAu(PPh3)}(dppe)Cp∗ afforded Ru{CCCC(CN)2CC(CN)2Au(PPh3)}(dppe)Cp∗ 4 by formal replacement of I+ by [Au(PPh3)]+. XRD structures of 1-4 are reported. 相似文献