Über die Natur agostischer Wechselwirkungen in Übergangsmetall-Amido-Komplexen

Formation of Agostic Structures Driven by London Dispersion

Agostic interactions between a C-H bond and a transition metal are commonly crucial in catalytic polymerization processes. Herein, a quantitative study of the nature of β-agostic interactions in a series of systems of importance in C-H bond activation reactions is reported. The analysis, characterized by the use of a coupled-cluster-based energy decomposition scheme, demonstrates that short-range London dispersion between the agostic C-H bond and the metal center plays a fundamental role in affecting the structural stability of these systems, contrary to a widely held view. These results are used to rationalize a series of previously published experimental findings.

Efficient access to titanaaziridines by C-H activation of N-methylanilines at ambient temperature

Titanaaziridines or η(2)-imine titanium complexes are considered key intermediates of the titanium-catalyzed hydroaminoalkylation of alkenes. Herein, we present an efficient synthetic route to this class of compounds, starting from N-methylanilines and a bis(η(5):η(1)-pentafulvene)titanium complex. Consecutive reactions on the η(2)-methyleneaniline complexes, characterized for the first time, prove a high chemical versatility. In particular, hydroaminoalkylation products were found in reactions of the three-membered titanacycles with alkenes. For the first time, all the intermediates of the hydroaminoalkylation of alkenes were isolated and characterized.