Cyclometalated Tantalum Diphenolate Pincer Complexes: Intramolecular C−H/M−CH<sub>3</sub> σ-Bond Metathesis May Be Faster than O−H/M−CH<sub>3</sub> Protonolysis
作者:Theodor Agapie、John E. Bercaw
DOI:10.1021/om700284c
日期:2007.6.1
with TaCl2(CH3)3. Deuterium labeling of the phenol hydrogens and of the linking 1,3-benzenediyl ring reveals an unexpected mechanism involving protonolysis of a methyl group, followed by C−H/Ta−CH3 σ-bond metathesis, leading to cyclometalation of the linking ring and finally protonation of the cyclometalated group by the pendant phenol.
Synthesis and Reactivity of Tantalum Complexes Supported by Bidentate X<sub>2</sub> and Tridentate LX<sub>2</sub> Ligands with Two Phenolates Linked to Pyridine, Thiophene, Furan, and Benzene Connectors: Mechanistic Studies of the Formation of a Tantalum Benzylidene and Insertion Chemistry for Tantalum−Carbon Bonds
作者:Theodor Agapie、Michael W. Day、John E. Bercaw
DOI:10.1021/om8002653
日期:2008.12.8
phosphine coordination to the resulting benzylidene species. An X-raystructure determination reveals that the benzylidene π-bond is oriented perpendicular to the oxygen−oxygen vector, in accord with the prediction of DFT calculations. Tantalum alkyl complexes with the benzene-linked bis(phenolate) ligand (Ta(CH3)2[(OC6H2-tBu2)2C6H3] (16), Ta(CH2Ph)2[(OC6H2-tBu2)2C6H3] (17), and TaCl2CH3[(OC6H2-tBu2)2C6H4]