Late-Metal Catalysts for Ethylene Homo- and Copolymerization

Ittel, Steven D.; Johnson, Lane R.; Brookhart, Maurice

doi:10.1021/cr9804644

Cited by 3,038 publications

(2,092 citation statements)

References 203 publications

Supporting

Mentioning

2,019

Contrasting

Unclassified

Order By: Relevance

“…It is a concerted reaction that combines an unsaturated ligand with an adjacent metal-ligand bond to form a product containing a new ligand with the unsaturated group formally inserted into the original covalent metalligand bond (Scheme 1). A variety of unsaturated ligands undergo migratory insertion, including carbon monoxide, carbon dioxide, alkenes, alkynes, ketones, aldehydes, and imines, and migratory insertion is a common step in numerous catalytic reactions, including hydroformylation, [1,2] hydrogenation, [3][4][5] polymerization, [6][7][8][9] hydroarylation, [10][11][12][13][14] difunctionalization of alkenes, [15][16][17][18] and the olefination of aryl halides (commonly termed the Mizoroki-Heck reaction). [19][20][21][22] In most cases, the unsaturated ligand inserts into a metalcarbon (M À C) or metal-hydrogen (M À H) bond.…”

Section: Introductionmentioning

confidence: 99%

Iridium-Catalyzed, Intermolecular Hydroetherification of Unactivated Aliphatic Alkenes with Phenols

Sevov

Hartwig

2013

J. Am. Chem. Soc.

View full text Add to dashboard Cite

Metal-catalyzed addition of an O−H bond to an alkene is a desirable process because it allows for rapid access to ethers from abundant starting materials without the formation of waste, without rearrangements, and with the possibility to control the stereoselectivity. We report the intermolecular, metal-catalyzed addition of phenols to unactivated α-olefins. Mechanistic studies of this rare catalytic reaction revealed a dynamic mixture of resting states that undergo O−H bond oxidative addition and subsequent olefin insertion to form ether products.

show abstract

Section: Introductionmentioning

confidence: 99%

Iridium-Catalyzed, Intermolecular Hydroetherification of Unactivated Aliphatic Alkenes with Phenols

Sevov

Hartwig

2013

J. Am. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…[1][2][3][4][5][6] Catalysis of such reactions by late transition metal (TM) complexes has received much recent attention due to their lower electrophilicity and thus greater heteroatom tolerance (versus comparable early TM complexes). 7 Moreover, such metals are relatively inexpensive in relation to the noble metals.…”

Section: Introductionmentioning

confidence: 99%

Activation of Carbon−Hydrogen and Hydrogen−Hydrogen Bonds by Copper−Nitrenes: A Comparison of Density Functional Theory with Single- and Multireference Correlation Consistent Composite Approaches

Tekarli

Williams

Cundari

2009

J. Chem. Theory Comput.

View full text Add to dashboard Cite

Abstract:The kinetics and thermodynamics of copper-mediated nitrene insertion into C-H and H-H bonds (the former of methane) have been studied using several levels of theory: B3LYP/6-311++G(d,p), B97-1/cc-pVTZ, PBE1KCIS/cc-pVTZ, and ccCA (correlation consistent Composite Approach). The results show no significant difference among the DFT methods. All three DFT methods predict the ground state of the copper-nitrene model complex, L′Cu(NH), to be a triplet, while single reference ccCA predicts the singlet to be the ground state. The contributions to the total ccCA energy indicate that the singlet state is favored at the MP2/CBS level of theory, while electron correlation beyond this level (CCSD(T)) favors a triplet state, resulting in a close energetic balance between the two states. A multireference ccCA method is applied to the nitrene active species and supports the assignment of a singlet ground state. In general, the largest difference in the model reaction cycles between DFT and ccCA methods is for processes involving radicals and bond dissociation.

show abstract

“…The reaction mixture was refluxed for 15 h at 80 o C, diluted with 300 mL of ethyl acetate and washed with 100 mL of water. The organic layer was dried over MgSO 4 and concentrated under reduced pressure. The residue was purified by flash chromatography (SiO 2 , EtOAcHexane = 1 : 2) to give a product as a yellow solid 13.8 g (yield=83%).…”

Section: Methodsmentioning

confidence: 99%

“…A new series of iron and cobalt complexes with bis (imino)pyridyl ligands were reported by Gibson, 1 Bennett from Dupont 2 and Brookhart, 3,4 which showed exceptionally high activity for the ethylene polymerization. Bulky bis (imino)pyridyl ligands have drawn considerable interest because they showed the potential advantages of modulating steric and electronic properties by varying the amine or aniline used in the ligand synthesis.…”

Section: Introductionmentioning

confidence: 99%

Allyloxy- and benzyloxy-substituted pyridine-bis-imine iron(II) and cobalt(II) complexes for ethylene polymerization

et al. 2005

View full text Add to dashboard Cite

A series of ethylene polymerization catalysts based on tridentate bis-imine ligands coordinated to iron and cobalt was reported. The ligands were prepared through the condensation of sterically bulky anilines with allyloxy-and benzyloxy-substituted 2,6-acetylpyridines. The pre-catalyst complexes were penta-coordinate species of the general formula {[(ArN=C(Me)) 2 (4-RO-C 5 H 3 N)]MCl 2 } (Ar=ortho dialkyl-substituted aryl ring; R=allyl, benzyl; M=Fe, Co). In the presence of ethylene and methyl alumoxane cocatalysts, these complexes were active for the polymerization of ethylene, with activities lower than those of metal complexes of the general formula {[(2-ArN= C(Me)) 2 C 5 H 3 N]MCl 2 } (Ar=ortho dialkyl-substituted aryl ring; M=Co, Fe), containing no substituents in 2,6-acetylpyridine ring. The effects of the catalyst structure and temperature on the polymerization activity, thermal properties, and molecular weight were discussed.

show abstract

Late-Metal Catalysts for Ethylene Homo- and Copolymerization

Cited by 3,038 publications

References 203 publications

Iridium-Catalyzed, Intermolecular Hydroetherification of Unactivated Aliphatic Alkenes with Phenols

Iridium-Catalyzed, Intermolecular Hydroetherification of Unactivated Aliphatic Alkenes with Phenols

Activation of Carbon−Hydrogen and Hydrogen−Hydrogen Bonds by Copper−Nitrenes: A Comparison of Density Functional Theory with Single- and Multireference Correlation Consistent Composite Approaches

Allyloxy- and benzyloxy-substituted pyridine-bis-imine iron(II) and cobalt(II) complexes for ethylene polymerization

Contact Info

Product

Resources

About