Seminar
Tuesday, April 25, 2017 - 12:00am
Graduate student Godfred Fianu will be presenting
“Titanocene(III) complexes: A promising reagent for the design of sustainable catalytic processes”
on April 25, 2017 at 4:10 PM in Neville Hall, Room 3.
Abstract: Titanocene(III) complexes are important single-electron reductants that have been used extensively for a variety of stoichiometric as well as catalytic reactions. Owing to their intrinsic ability to alternate between the +3 and +4 oxidation states, titanocene(III) complexes are attractive reagents for designing efficient atom-economical processes. In this seminar, a detailed mechanistic study of an atom-economical radical arylation of amino-epoxides, catalyzed by titanocene(III) chloride, to form indoline derivatives will be presented. Information gleaned from our studies, which include the role of salt additives and the turnover-limiting step, was used to further fine-tune and enhance this radical arylation process to incorporate a wider range of amino-epoxides.1–3 Also, an in-depth understanding of the impact of solvent and of ligands attached to titanocene(III) has led the discovery of cationic titanocene(III) complexes as viable, stable catalysts for performing the radical arylation of amino-epoxides to form indoline products.4 Finally, a procedurally straightforward, inexpensive, and mild approach for the reduction of aldehydes and ketones to alcohols via a titanocene(III) borohydride-PMHS system will be presented.5 References: 1. Gansa uer, A.; Behlendorf, M.; Laufenberg, D. Von; Fleckhaus, A.; Kube, C.; Sadasivam, D. V; Flowers II, R. A. Angew. Chemie - Int. Ed. 2012, 4739–4742. 2. Gansa uer, A.; Kube, C.; Daasbjerg, K.; Sure, R.; Grimme, S.; Fianu, G. D.; Sadasivam, D. V.; Flowers, R. A. J. Am. Chem. Soc. 2014, 136 (4), 1663–1671. 3. Gansa uer, A.; Von Laufenberg, D.; Kube, C.; Dahmen, T.; Michelmann, A.; Behlendorf, M.; Sure, R.; Seddiqzai, M.; Grimme, S.; Sadasivam, D. V.; Fianu, G. D.; Flowers, R. A. Chem. - A Eur. J. 2015, 21, 280–289. 4. Gansa uer, A.; Hildebrandt, S.; Michelmann, A.; Dahmen, T.; von Laufenberg, D.; Kube, C.; Fianu, G. D.; Flowers, R. A. Angew. Chemie - Int. Ed. 2015, 54, 7003–7006. 5. Fianu, G. D.; Schipper, K. C.; Flowers, R. A. Manuscript in preparation