Cp TiX Complexes for Sustainable Catalysis in Single-Electron Steps.

We present a combined electrochemical, kinetic, and synthetic study with a novel and easily accessible class of titanocene catalysts for catalysis in single-electron steps. The tailoring of the electronic properties of our Cp TiX-catalysts that are prepared in situ from readily available Cp TiX is achieved by varying the anionic ligand X. Of the complexes investigated, Cp TiOMs proved to be either equal or substantially superior to the best catalysts developed earlier.

Cationic Titanocene(III) Complexes for Catalysis in Single-Electron Steps.

By exploiting solvent and anion effects, [Cp2Ti](+) complexes for atom-economical catalysis in single-electron steps were developed and applied for the first time. These complexes constitute remarkably stable and active catalysts for radical arylations. The reaction kinetics and catalyst composition were studied by cyclic voltammetry and in situ IR spectroscopy.

Mechanistic study of the titanocene(III)-catalyzed radical arylation of epoxides.

An atom-economical and catalytic arylation of epoxide-derived radicals is described. The key step of the catalytic system is a sequential electron and proton transfer for the rearomatization of the radical σ-complex and catalyst regeneration. Kinetic, computational, spectroscopic, and cyclovoltammetric investigations highlight the key issues of the reaction mechanism and catalyst stabilization by collidine hydrochloride.

Substituent effects and supramolecular interactions of titanocene(III) chloride: implications for catalysis in single electron steps.

The electrochemical properties of titanocene(III) complexes and their stability in THF in the presence and absence of chloride additives were studied by cyclic voltammetry (CV) and computational methods. The anodic peak potentials of the titanocenes can be decreased by as much as 0.47 V through the addition of an electron-withdrawing substituent (CO2Me or CN) to the cyclopentadienyl ring when compared with Cp2TiCl.