@article {4996,
	title = {Thermal activation of hydrocarbon C-H bonds by tungsten alkylidene complexes},
	journal = {Journal of the American Chemical Society},
	volume = {123},
	number = {4},
	year = {2001},
	note = {ISI Document Delivery No.: 396RTTimes Cited: 32Cited Reference Count: 80},
	month = {Jan},
	pages = {612-624},
	type = {Article},
	abstract = {Thermal activation of Cp*W(NO)(CH2CMe3)(2) (1) in neat hydrocarbon solutions transiently generates the neopentylidene complex, Cp*W(NO)(=CHCMe3) (A), which subsequently activates solvent C-H bonds. For example, the thermolysis of 1 in tetramethylsilane and perdeuteriotetramethylsilane results in the clean formation of Cp*W(NO)(CH2CMe3)(CH2SiMe3) (2) and Cp*W(NO)(CHDCMe3)[CD2Si(CD3)(3)] (2-d(12)), respectively, in virtually quantitative yields. The neopentylidene intermediate A can be trapped by PMe3 to obtain Cp*W(NO)(=CHCMe3)(PMe3) in two isomeric forms (4a-b), and in benzene, 1 cleanly forms the phenyl complex Cp*W(NO)(CH2CMe3)(C6H5) (5). Kinetic and mechanistic studies indicate that the C-H activation chemistry derived from 1 proceeds through two distinct steps, namely, (1) rate-determining intramolecular alpha -H elimination of neopentane from 1 to form A and (2) 1,2-cis addition of a substrate C-H bond across the W=C linkage in A. The thermolysis of 1 in cyclohexane in the presence; of PMe3 yields 4a-b as well as the olefin complex Cp*W(NO)(eta (2)-cyclohexene)(PMe3) (6). In contrast, methylcyclohexane and ethylcyclohexane afford principally the allyl hydride complexes Cp*W(NO)(eta (3)-C7H11)(H) (7a-b) and Cp*W(NO)(eta (3)-C8H13)(H) (8a-b), respectively, under identical experimental conditions. The thermolysis of 1 in toluene affords a surprisingly complex mixture of six products. The two major products are the neopentyl aryl complexes, Cp*W(NO)(CH2CMe3)(C6H4-3-Me) (9a) and Cp*W(NO)(CH2CMe3)(C6H4-4-Me) (9b), in approximately 47 and 33\% yields. Of the other four products, one is the aryl isomer of 9a-b, namely, Cp*W(NO)(CH2CMe3)(C6H4-2-Me) (9c) (similar to1\%). The remaining three products all arise from the incorporation of two molecules of toluene; namely, Cp*W(NO)(CH2C6H5)(C6H4-3-Me) (11a; similar to 12\%), Cp*W(NO)(CH2C6H5)(C6H4-4-Me) (11b; similar to6\%), and Cp*W(NO)(CH2C6H5)(2) (10; similar to1\%). It has been demonstrated that the formation of complexes 10 and 11a-b involves the transient formation of Cp*W(NO)(CH2CMe3)(CH2C6H5) (12), the product of toluene activation at the methyl position, which reductively eliminates neopentane to generate the C-H activating benzylidene complex Cp*W(NO)(=CHC6H5) (B). Consistently, the thermolysis of independently prepared 12 in benzene and benzene-d(6) affords Cp*W(NO)(CH2C6H5)(C6H5) (13) and Cp*W(NO)(CHDC6H5)(C6D5) (13-d(6)), respectively, in addition to free neopentane. Intermediate B can also be trapped by PMe3 to obtain the adducts Cp*W(NO)(=CHC6H5)(PMe3) (14a-b) in two rotameric forms. From their reactions with toluene, it can be deduced that both alkylidene intermediates A and B exhibit a preference for activating the stronger aryl sp(2) C-H bonds. The C-H activating ability of B also encompasses aliphatic substrates as well as it reacts with tetramethylsilane and cyclohexanes in a manner similar to that summarized above for A. All new complexes have been characterized by conventional spectroscopic methods, and the solid-state molecular structures of 4a, 6, 7a, 8a, and 14a have been established by X-ray diffraction methods.},
	keywords = {2-RH-ELIMINATION, INSERTION REACTIONS, LIGANDS, {1},
	isbn = {0002-7863},
	url = {<Go to ISI>://000166650900011},
	author = {Adams, C. S. and Legzdins,Peter and Tran, E.}
}
@article {4735,
	title = {Synthesis and structure of Pd(II) complexes containing chelating (phosphinomethyl)oxazoline P,N-type ligands; copolymerisation of ethylene/CO},
	journal = {Journal of the Chemical Society-Dalton Transactions},
	volume = {7},
	number = {7},
	year = {2000},
	note = {ISI Document Delivery No.: 298WZTimes Cited: 56Cited Reference Count: 57},
	pages = {1067-1074},
	type = {Article},
	abstract = {The ligands (2-oxazoline-2-ylmethyl)diphenylphosphine (III or PCH(2)ox) and (2-oxazoline-2-ylmethyl-4,4-dimethyl)diphenylphosphine (IV or PCH(2)ox(Me2)) have been used as chelates towards Pd(II) methyl complexes. The complexes [PdMe(Cl)(PCH(2)ox)] 2a and [PdMe(Cl)(PCH(2)ox(Me2))] 2b were obtained from [PdMe(Cl)(cod)] (cod = cycloocta-1,5-diene) in 83\% and 94\% yield, respectively, and compared to [PdCl2(PCH(2)ox(Me2))] 1 which was characterised by X-ray diffraction. A series of cationic methyl complexes obtained by chloride abstraction in the presence of MeCN, SMe2, P(OPh)(3) or no added donor except the counter ion were prepared in order to evaluate their catalytic performances in ethylene/CO copolymerisation.},
	keywords = {CARBON-MONOXIDE, CATALYZED ALTERNATING COPOLYMERIZATION, CH3CN, CRYSTAL-STRUCTURES, INSERTION REACTIONS, {ALLYLIC SUBSTITUTIONS},
	isbn = {0300-9246},
	url = {<Go to ISI>://000086163700014},
	author = {Braunstein, P. and Fryzuk,Michael D. and Le Dall, M. and Naud, F. and Rettig, S. J. and Speiser, F.}
}
