@article {2495, title = {Broadening the Scope of Group 4 Hydroamination Catalysis Using a Tethered Ureate Ligand}, journal = {Journal of the American Chemical Society}, volume = {131}, number = {51}, year = {2009}, note = {ISI Document Delivery No.: 543YATimes Cited: 12Cited Reference Count: 34Leitch, David C. Payne, Philippa R. Dunbar, Christine R. Schafer, Laurel L.}, month = {Dec}, pages = {18246-+}, type = {Article}, abstract = {A broadly applicable group-4-based precatalyst for the hydroamination of primary and secondary amines was developed. Screening experiments involving a series of amide and urea proligands led to the discovery of a tethered bis(ureate) zirconium complex with unprecedented reactivity in the intermolecular hydroamination of alkynes and the intramolecular hydroamination of alkenes. This catalyst system is effective with primary and secondary amines, 1,2-disubstituted alkenes, and heteroatom-containing functional groups, including ethers, silanes, amines, and heteroaromatics. The gem-disubstituent effect is not required for cyclization. The catalyst is generally regioselective for the anti-Markovnikov product of intermolecular alkyne hydroamination, and chemoselective for hydroamination over alpha-alkylation when forming 6- and 7-membered rings from aminoalkenes.}, keywords = {ALKYNES, AMIDATE COMPLEXES, AMINES, AMINOALKENES, BOND FORMATION, INTRAMOLECULAR HYDROAMINATION, METAL-CATALYSTS, TITANIUM, UNACTIVATED ALKENES, ZIRCONIUM}, isbn = {0002-7863}, url = {://000273615800028}, author = {Leitch, D. C. and Payne, P. R. and Dunbar, C. R. and Schafer, L. L.} }