@article {2027,
	title = {Transformations of cyclic olefins mediated by tungsten nitrosyl complexes},
	journal = {Organometallics},
	volume = {27},
	number = {18},
	year = {2008},
	note = {ISI Document Delivery No.: 348URTimes Cited: 3Cited Reference Count: 35Buschhaus, Miriam S. A. Pamplin, Craig B. Blackmore, Ian J. Legzdins, Peter},
	month = {Sep},
	pages = {4724-4738},
	type = {Article},
	abstract = {This report describes investigations that have elucidated the nature, extent, and mechanism of the cyclic-olefin oligomerization effected by a series of tungsten precatalysts, with particular focus on Cp*W(NO)(CH2CMe3)(2) (1) and Cp*W(NO)(CH2SiMe3)(eta(2)-CPhCH2) (2). Upon thermolysis, these precatalysts oligomerize simple cyclic olefins, from cyclopentene to cyclooctene, into ring-retaining oligomers as high as dodecamers (depending on the substrate) with remaining sites of unsaturation. Precatalyst initiation involves the coupling of one equivalent of the substrate with the reactive 16e intermediate thermally generated by the precatalyst (i.e., an alkylidene by 1 or an eta(2)-alkyne complex by 2), followed by rearrangement of the coupled ligand in the metal{\textquoteright}s coordination sphere either to an olefin or to a diene (with concomitant loss of two hydrogen atoms). The rearranged ligand is displaced from the metal center as two equivalents of substrate coordinate to form a putative bis-olefin complex, Cp*W(NO)(cyclic olefin)2, that represents the convergent entry point to the catalytic cycle for the precatalysts. The coordinated olefins undergo metal-mediated coupling to form a metallacyclopentane complex. The metallacycle then undergoes beta-hydrogen activation and reductive elimination to generate an eta(2)-cyclic-olefin dimer. Further incorporation of substrate leads to formation of trimers and higher oligomers. Alternatively, expulsion of any coordinated oligomer from the tungsten center regenerates the reactive bis-olefin complex. Finally, decomposition of the tungsten catalyst species is consistent with a bimetallic pathway. All new organometallic complexes have been characterized by conventional spectroscopic and analytical methods, and the solid-state molecular structures of several compounds have been established by X-ray crystallographic analyses.},
	keywords = {1, 3-CYCLOHEXADIENE, ALKYLIDENE COMPLEXES, C-H ACTIVATION, CATALYTIC-ACTIVITY, CRYSTAL-STRUCTURES, CYCLOHEXENE, METATHESIS, MOLYBDENACYCLOBUTANES, MOLYBDENUM, REACTIVITY},
	isbn = {0276-7333},
	url = {<Go to ISI>://000259236100022},
	author = {Buschhaus, M. S. A. and Pamplin, C. B. and Blackmore, I. J. and Legzdins,Peter}
}
@article {706,
	title = {Thermal activation of hydrocarbon C-H bonds by Cp*M(NO) complexes of molybdenum and tungsten},
	journal = {Accounts of Chemical Research},
	volume = {36},
	number = {4},
	year = {2003},
	note = {ISI Document Delivery No.: 669GJTimes Cited: 54Cited Reference Count: 36},
	month = {Apr},
	pages = {223-233},
	type = {Review},
	abstract = {Gentle thermolysis of appropriate Cp*M(NO)(hydrocarbyl)(2) complexes (Cp* = eta(5)-C5Me5) of molybdenum and tungsten results in loss of hydrocarbon and the transient formation of 16-electron Cp*M(NO)-containing complexes such as Cp*M(NO)(alkylidene), Cp*M(NO)(eta(2)-benzyne), Cp*M(NO)(eta(2)-acetylene), and Cp*M(NO)(eta(2)-allene) (M = Mo, W). These intermediates effect the single, double, or triple activation of hydrocarbon C-H bonds intermolecularly, the first step of these activations being the reverse of the transformations by which they were generated. This Account summarizes the various types of C-H activations that have been effected with these nitrosyl complexes and also describes the results of kinetic, mechanistic, and theoretical investigations of these processes.},
	keywords = {ALKANES, ALKYLIDENE COMPLEXES, ARENES, CHEMISTRY, INTERMEDIATE, NITROSYL, REACTIVITY, REDUCTIVE ELIMINATION, THERMOLYSIS, TRANSITION-METAL BONDS},
	isbn = {0001-4842},
	url = {<Go to ISI>://000182343300001},
	author = {Pamplin, C. B. and Legzdins,Peter}
}
@article {699,
	title = {Thermal activation of hydrocarbon C-H bonds initiated by a tungsten allyl complex},
	journal = {Journal of the American Chemical Society},
	volume = {125},
	number = {49},
	year = {2003},
	note = {ISI Document Delivery No.: 750QETimes Cited: 12Cited Reference Count: 62},
	month = {Dec},
	pages = {15210-15223},
	type = {Article},
	abstract = {Gentle thermolysis of the allyl complex, (CpW)-W-*(NO)(CH2CMe3)(eta(3)-H2CCHCMe2) (1), at 50 degreesC in neat hydrocarbon solutions results in the loss of neopentane and the generation of transient intermediates that subsequently activate solvent C-H bonds. Thus, thermal reactions of 1 with tetramethylsilane, mesitylene, and benzene effect single C-H activations and lead to the exclusive formation of (CpW)-W-*(NO)(CH2SiMe3)(eta(3)-H2CCHCMe2) (2), (CpW)-W-*(NO)(CH2C6H3-3,5-Me-2)(eta(3)-H2CCHCMe2) (3), and (CpW)-W-*(NO)(C6H5)(eta(3)-H2CCHCMe2) (4), respectively. The products of reactions of 1 with other methyl-substituted arenes indicate an inherent preference of the system for the activation of stronger arene sp(2) C-H bonds. For example, C-H bond activation of p-xylene leads to the formation of (CpW)-W-*(NO)(CH2C6H4-4-Me)(eta(3)-H2CCHCMe2) (5) (26\%) and (CpW)-W-*(NO)(C6H3-2,5-Me-2)(eta(3)-H2CCHCMe2) (6) (74\%). Mechanistic and labeling studies indicate that the transient C-H-activating intermediates are the allene complex, (CpW)-W-*(NO)(eta(2)-H2C=C=CMe2) (A), and the eta(2)-diene complex, (CpW)-W-*(NO)(eta(2)-H2C=CHC(Me)=CH2) (B). Intermediates A and B react with cyclohexene to form (CpW)-W-*(NO)(eta(3)-CH2C(2-cyclohexenyl)CMe2)(H) (18) and (CpW)-W-*(NO)(eta(3)-CH2CHC)(Me)CH2CbetaH(C4H8)CalphaH (19), respectively, and intermediate A can be isolated as its PMe3 adduct, (CpW)-W-*(NO)(PMe3)(eta(2)-H2C=C=CMe2) (20). Interestingly, thermal reaction of 1 with 2,3-dimethylbut-2-ene results in the formation of a species that undergoes eta(3) {\textendash}> eta(1) isomerization of the dimethylallyl ligand following the initial C-H bond-activating step to yield (CpW)-W-*(NO)(eta(3)-CMe2CMeCH2)(eta(1)-CH2CHCMe2) (21). Thermolyses of 1 in alkane solvents afford allyl hydride complexes resulting from three successive C-H bond-activation reactions. For instance, 1 in cyclohexane converts to (CpW)-W-*(NO)(eta(3)-C6H9)(H) (22) with dimethylpropylcyclohexane being formed as a byproduct, and in methylcyclohexane it forms the two isomeric complexes, (CpW)-W-*(NO)(eta(3)-C7H11)(H) (23a,b). All new complexes have been characterized by conventional spectroscopic methods, and the solid-state molecular structures of 2, 3, 4, 18, 19, 20, and 21 have been established by X-ray crystallographic analyses.},
	keywords = {ALKYLIDENE COMPLEXES, ALLENE, CHEMICAL-PROPERTIES, COMPLEXES, CRYSTAL-STRUCTURE, ETA-3-ALLYL COMPLEXES, MOLECULAR-STRUCTURE, ORGANOMETALLIC NITROSYL CHEMISTRY, SOLID-STATE, STRUCTURAL CHARACTERIZATION, TRANSITION-METAL COMPLEXES},
	isbn = {0002-7863},
	url = {<Go to ISI>://000187007400050},
	author = {Ng, S. H. K. and Adams, C. S. and Hayton, T. W. and Legzdins,Peter and Patrick, B. O.}
}
