A cyclic-voltammetry-based screening method for Cp TiX-catalyzed reactions is introduced. Our mechanism-based approach enables the study of the influence of various additives on the electrochemically generated active catalyst Cp TiX, which is in equilibrium with catalytically inactive [Cp TiX ] . Thioureas and ureas are most efficient in the generation of Cp TiX in THF. Knowing the precise position of the equilibrium between Cp TiX and [Cp TiX ] allowed us to identify reaction conditions for the bulk electrolysis of Cp TiX complexes and for Cp TiX-catayzed radical arylations without having to carry out the reactions. Our time- and resource-efficient approach is of general interest for the design of catalytic reactions that proceed in single-electron steps.

Cyclic voltammetry‐based screening method for Cp2TiX‐catalyzed reactions is extended to the screening of solvents other than tetrahydrofuran for bulk electrolysis of the catalyst and radical arylation. It was found that CH3CN can be used as a solvent for both processes without additives. Furthermore, in tetrahydrofuran, squaramide L2 is more efficient than the previously reported supramolecular halide binder, Schreiner's thiourea L1. The results extend the usefulness of the proposed time and resource‐efficient screening method for designing catalysis reactions in single‐electron steps.

The combination of synthesis, rotating ring‐disk electrode (RRDE) and cyclic voltammetry (CV) measurements, and computational investigations with the aid of DFT methods shows how a thiourea, a squaramide, and a bissulfonamide as additives affect the EqCr equilibrium of Cp2TiCl2. We have, for the first time, provided quantitative data for the EqCr equilibrium and have determined the stoichiometry of adduct formation of [Cp2Ti(III)Cl2]−, [Cp2Ti(III)Cl] and [Cp2Ti(IV)Cl2] and the additives. By studying the structures of the complexes formed by DFT methods, we have established the Gibbs energies and enthalpies of complex formation as well as the adduct structures. The results not only demonstrate the correctness of our use of the EqCr equilibrium as predictor for sustainable catalysis. They are also a design platform for the development of novel additives in particular for enantioselective catalysis.

Ac yclic-voltammetry-based screening method for Cp 2 TiX-catalyzed reactions is introduced. Our mechanismbased approach enables the study of the influence of various additives on the electrochemically generated active catalyst Cp 2 TiX, which is in equilibrium with catalytically inactive [Cp 2 TiX 2 ] À .T hioureas and ureas are most efficient in the generation of Cp 2 TiXinTHF.Knowing the precise position of the equilibrium between Cp 2 TiXand [Cp 2 TiX 2 ] À allowed us to identify reaction conditions for the bulk electrolysis of Cp 2 TiX 2 complexes and for Cp 2 TiX-catayzed radical arylations without having to carry out the reactions.O ur time-and resourceefficient approach is of general interest for the design of catalytic reactions that proceed in single-electron steps.Catalysis in single-electron steps [1] and metalloradical catal-

What mechanism‐based screening for titanocene catalysis is all about! Combining the methods of computational chemistry and electrochemistry provides the structural and quantitative means for an efficient optimization of reaction conditions in the H‐bond donor‐assisted, titanocene‐catalyzed radical arylation of epoxides. These methods give an answer to how and why condition screening in titanocene catalysis works! More information can be found in the Full Paper by A. Gansäuer et al. on page 4903.