@article {2494, title = {N,O-Chelates of Group 4 Metals: Contrasting the Use of Amidates and Ureates in the Synthesis of Metal Dichlorides}, journal = {European Journal of Inorganic Chemistry}, number = {18}, year = {2009}, note = {ISI Document Delivery No.: 467LNTimes Cited: 5Cited Reference Count: 69Leitch, David C. Beard, J. David Thomson, Robert K. Wright, Vincent A. Patrick, Brian O. Schafer, Laurel L.}, month = {Jun}, pages = {2691-2701}, type = {Article}, abstract = {A series of dichloride complexes of titanium and zirconium with amidate and ureate ancillary ligands have been prepared, Three examples of bis(amidate)dichlorotitanium and zirconium complexes were effectively synthesized through salt metathesis with metal tetrachloride as starting materials. Optimum results were achieved using sodium amidate salts formed from sodium bis(trimethylsilyl)amide and neutral amide proligands, while other methods were ineffective. Use of electron-donating ureate ligands in lieu of amidates enables preparation through alternate routes. Protonolysis of Ti(NMe2)(2)Cl-2 and Zr(NMe2)(2)Cl-2(dme) with urea proligands leads to dichlorobis(ureate) complexes in good yield. Using a tethered bis(ureate) ligand eliminates the fluxional behaviour and coordination isomerism observed for both bis(amidate) and bis(ureate) zirconium complexes. ((C) Wiley-VCH Verlag GmbH \& Co. KGaA, 69451 Weinheim, Germany, 2009)}, keywords = {amidate, BIS(AMIDATE) TITANIUM PRECATALYST, CATALYTIC, Chelates, COORDINATION CHEMISTRY, EARLY, GUANIDINATE LIGANDS, HYDROAMINATION, INTERMOLECULAR HYDROAMINATION, N, O ligands, OLEFIN POLYMERIZATION, SOLUTION DYNAMICS, STRUCTURAL-CHARACTERIZATION, TITANIUM, TRANSITION-METALS, Ureate, ZIEGLER-NATTA POLYMERIZATION, ZIRCONIUM}, isbn = {1434-1948}, url = {://000267740500015}, author = {Leitch, D. C. and Beard, J. D. and Thomson, R. K. and Wright, V. A. and Patrick, B. O. and Schafer, L. L.} } @article {2363, title = {Selective C-H Activation alpha to Primary Amines. Bridging Metallaaziridines for Catalytic, Intramolecular alpha-Alkylation}, journal = {Journal of the American Chemical Society}, volume = {131}, number = {6}, year = {2009}, note = {ISI Document Delivery No.: 427PWTimes Cited: 22Cited Reference Count: 28Bexrud, Jason A. Eisenberger, Patrick Leitch, David C. Payne, Philippa R. Schafer, Laurel L.}, month = {Feb}, pages = {2116-+}, type = {Article}, abstract = {Selective alpha-C-H activation results in the synthesis of the first bridging metallaaziridine complex for the catalytic alpha-alkylation of primary amines. Reaction development led to the preparation of new Zr 2-pyridonate complexes for this useful transformation. No nitrogen protecting groups are required for this reaction, which is capable of assembling quaternary chiral centers a to nitrogen. Preliminary mechanistic investigations suggest bridging metallaaziridine species are the catalytically active intermediates for this alpha-functionalization reaction, while monomeric imido complexes furnish azepane hydroamination products.}, keywords = {ALKENES, ALKYNES, BOND ACTIVATION, COMPLEXES, GENERATION, HYDROAMINOALKYLATION, INTERMOLECULAR HYDROAMINATION, NITROGEN, REACTIVITY, UNACTIVATED OLEFINS}, isbn = {0002-7863}, url = {://000264792200038}, author = {Bexrud, J. A. and Eisenberger, P. and Leitch, D. C. and Payne, P. R. and Schafer, L. L.} } @article {1601, title = {A pentagonal pyramidal zirconium imido complex for catalytic hydroamination of unactivated alkenes}, journal = {Organometallics}, volume = {25}, number = {17}, year = {2006}, note = {ISI Document Delivery No.: 070PZTimes Cited: 66Cited Reference Count: 40Thomson, Robert K. Bexrud, Jason A. Schafer, Laurel L.}, month = {Aug}, pages = {4069-4071}, type = {Article}, abstract = {The first, isolable group 4 imido complexes capable of promoting intramolecular olefin hydroamination for the preparation of N-containing heterocycles are presented. The structurally characterized 6-coordinate bis(amidate)-supported zirconium imido complex is a rare example of distorted-pentagonal-pyramidal geometry.}, keywords = {ALKYNE HYDROAMINATION, allenes, AMIDATE COMPLEXES, BIS(AMIDATE) TITANIUM PRECATALYST, C-H ACTIVATION, HYDROAMINATION, INTERMOLECULAR HYDROAMINATION, INTRAMOLECULAR, REACTIVITY, TEMPERATURE, TI(NME2)(4)}, isbn = {0276-7333}, url = {://000239536800007}, author = {Thomson, R. K. and Bexrud, J. A. and Schafer, L. L.} }