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Sequential ring-closing metathesis (RCM)-Kharasch cyclizations are promoted by the Grubbs metathesis catalysts and provide rapid access to bicyclic lactones and lactams. 相似文献
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Stephen A. Eastham Michael R. Hallett Andrea Modi James E. Painter Peter Quayle Dean C. Ricketts 《Tetrahedron》2008,64(5):936-948
The development of a formal synthesis of aflatoxin B2 is described, which utilizes a Dötz benzannulation reaction as a key step. 相似文献
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Asai S. Azuelos G. Buttar C. Cavasinni V. Costanzo D. Cranmer K. Harper R. Jakobs K. Kanzaki J. Klute M. Mazini R. Mellado B. Quayle W. Richter-Ws E. Takemoto T. Vivarelli I. Wu Sau Lan 《The European Physical Journal C - Particles and Fields》2003,32(2):s19-s54
The European Physical Journal C - The potential for the discovery of a Standard Model Higgs boson in the mass range m H < 2 m Z in the vector boson fusion mode has been studied for the ATLAS... 相似文献
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Michael R. Attwood Mark L. Lewis Peter Quayle Simon P. Thompson 《Tetrahedron letters》2006,47(21):3607-3611
α-Alkoxystannanes undergo oxidation upon treatment with cerium ammonium nitrate generating oxonium ions, which can be trapped in an intramolecular fashion affording furo[2,3-b]pyrans. 相似文献
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Adams CJ Bartlett IM Boonyuen S Connelly NG Harding DJ Hayward OD McInnes EJ Orpen AG Quayle MJ Rieger PH 《Dalton transactions (Cambridge, England : 2003)》2006,(28):3466-3477
Reduction of [M(CO)2(eta-RC[triple bond]CR')Tp']X {Tp' = hydrotris(3,5-dimethylpyrazolyl)borate, M = Mo, X = [PF6]-, R = R' = Ph, C6H4OMe-4 or Me; R = Ph, R' = H; M = W, X = [BF4]-, R = R' = Ph or Me; R = Ph, R' = H} with [Co(eta-C5H5)2] gave paramagnetic [M(CO)2(eta-RC[triple bond]CR')Tp'], characterised by IR and ESR spectroscopy. X-Ray structural studies on the redox pair [Mo(CO)2(eta-PhC[triple bond]CPh)Tp'] and [Mo(CO)2(eta-PhC[triple bond]CPh)Tp'][PF6] showed that oxidation is accompanied by a lengthening of the C[triple bond]C bond and shortening of the Mo-C(alkyne) bonds, consistent with removal of an electron from an orbital antibonding with respect to the Mo-alkyne bond, and with conversion of the alkyne from a three- to a four-electron donor. Reduction of [Mo(CO)(NCMe)(eta-MeC[triple bond]CMe)Tp'][PF6] with [Co(eta-C5H5)2] in CH2Cl2 gives [MoCl(CO)(eta-MeC[triple bond]CMe)Tp'], via nitrile substitution in [Mo(CO)(NCMe)(eta-MeC[triple bond]CMe)Tp'], whereas a similar reaction with [M(CO){P(OCH2)3CEt}(eta-MeC[triple bond]CMe)Tp']+ (M = Mo or W) gives the phosphite-containing radicals [M(CO){P(OCH2)3CEt}(eta-MeC[triple bond]CMe)Tp']. ESR spectroscopic studies and DFT calculations on [M(CO)L(eta-MeC[triple bond]CMe)Tp'] {M = Mo or W, L = CO or P(OCH2)3CEt} show the SOMO of the neutral d5 species (the LUMO of the d4 cations) to be largely d(yz) in character although much more delocalised in the W complexes. Non-coincidence effects between the g and metal hyperfine matrices in the Mo spectra indicate hybridisation of the metal d-orbitals in the SOMO, consistent with a rotation of the coordinated alkyne about the M-C2 axis. 相似文献
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William Clegg Fiona J. Lawlor Gerry Lesley Todd B. Marder Nicholas C. Norman A.Guy Orpen Michael J. Quayle Craig R. Rice Andrew J. Scott Fabio E.S. Souza 《Journal of organometallic chemistry》1998,550(1-2)
The synthesis and spectroscopic characterisation of the new diborane(4) compounds B2(1,2-O2C6Cl4)2 and B2(1,2-O2C6Br4)2 are reported together with the diborane(4) bis-amine adduct [B2(calix)(NHMe2)2] (calix=Butcalix[4]arene). B–B bond oxidative addition reactions between the platinum(0) compound [Pt(PPh3)2(η-C2H4)] and the diborane(4) compounds B2(1,2-S2C6H4)2, B2(1,2-O2C6Cl4)2 and B2(1,2-O2C6Br4)2 are also described which result in the platinum(II) bis-boryl complexes cis-[Pt(PPh3)2{B(1,2-S2C6H4)}2], cis-[Pt(PPh3)2{B(1,2-O2C6Cl4)}2] and cis-[Pt(PPh3)2{B(1,2-O2C6Br4)}2] respectively, the former two having been characterised by X-ray crystallography. In addition, the platinum complex [Pt(PPh3)2(η-C2H4)] reacts with XB(1,2-O2C6H4) (X=Cl, Br) affording the mono-boryl complexes trans-[PtX(PPh3)2{B(1,2-O2C6H4)}] as a result of oxidative addition of the B–X bonds to the Pt(0) centre; the chloro derivative has been characterised by X-ray crystallography. 相似文献