title: Titanium imido complexes stabilised by bis(iminophosphoranyl)methanide ligands: the influence of N-substituents on solution dynamics and reactivity.
abstract: Terminal titanium imido complexes of the general formula [Ti(N(t)Bu)Cl{CH(Ph2PNR)2}] 4 (R = Ph, (i)Pr, (t)Bu) are reported. These compounds were synthesized from the corresponding Li adducts 3 of BIPMH (bis(iminophosphoranyl)methanide) and Mountford's complex [Ti(N(t)Bu)Cl2(Py)3]. The crystal structures of two of the Ti complexes (R = Ph, (t)Bu) and two of the Li compounds (R = (i)Pr, (t)Bu) are reported. Dynamic solution NMR spectroscopy reveals a dynamic isomerisation process in the case of the Ti complex 4c (R = (t)Bu). DFT studies showed that this dynamic process comes from steric repulsion between the imido ligand and the (t)Bu N-substituents on the BIPMH ligand. Complexes 4 were tested in alkyne hydroamination; 4a (R = Ph) displayed modest catalytic activity in the reaction of aniline with phenylacetylene.
authors.affiliation: Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB) - UMR CNRS 6302, Université de Bourgogne, UFR Sciences et Techniques, 9 avenue Alain Savary, BP 47870 21078 Dijon, Cedex, France.
authors.forename: Adrien T
authors.initials: AT
authors.lastname: Normand
authors.forename: Alexandre
authors.initials: A
authors.lastname: Massard
authors.forename: Philippe
authors.initials: P
authors.lastname: Richard
authors.forename: Coline
authors.initials: C
authors.lastname: Canovas
authors.forename: Cédric
authors.initials: C
authors.lastname: Balan
authors.forename: Michel
authors.initials: M
authors.lastname: Picquet
authors.forename: Audrey
authors.initials: A
authors.lastname: Auffrant
authors.forename: Pierre
authors.initials: P
authors.lastname: Le Gendre