Catalysis via Homolytic Substitutions with C−O and Ti−O Bonds: Oxidative Additions and Reductive Eliminations in Single Electron Steps

• Published in: Journal of the American Chemical Society Vol. 131; no. 46; pp. 16989 - 16999
• Main Authors: Gansäuer, Andreas, Fleckhaus, André, Lafont, Manuel Alejandre, Okkel, Andreas, Kotsis, Konstantinos, Anoop, Anakuthil, Neese, Frank
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 25.11.2009; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Multidisciplinary; Physical Sciences; Science & Technology; AUXILIARY BASIS-SETS; ORGANIC-SYNTHESIS; STYRENE POLYMERIZATIONS; 5-EXO CYCLIZATIONS; RADICAL CYCLIZATION; EPOXYPOLYENE CYCLIZATION; CORRELATION-ENERGY; HOMOGENEOUS CATALYSIS; EPOXIDE OPENINGS; STRAIGHTFORWARD SYNTHESIS
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja907817y

In a combined theoretical and experimental study, an efficient catalytic reaction featuring epoxide opening and tetrahydrofuran formation through homolytic substitution reactions at C−O and Ti−O bonds was devised. The performance of these two key steps of the catalytic cycle was studied and could be adjusted by modifying the electronic properties of the catalysts through introduction of electron-donating or -withdrawing substituents to the titanocene catalysts. By regarding both steps as single electron versions of oxidative addition and reductive elimination, a mechanism-based platform for the design of catalysts and reagents for electron transfer reactions evolved that opens broad perspectives for further investigations.