2021, Leonard, David K., Li, Wu, Rockstroh, Nils, Junge, Kathrin, Beller, Matthias

The kinetic and thermodynamic stability of C(sp3)–C(sp3) bonds makes the site-selective activation of these motifs a real synthetic challenge. In view of this, herein a site-selective method of C(sp3)–C(sp3) bond scission of amines, specifically morpholine and piperazine derivatives, using a cheap iron catalyst and air as a sustainable oxidant is reported. Furthermore, a statistical design of experiments (DoE) is used to evaluate multiple reaction parameters thereby allowing for the rapid development of a catalytic process. © 2021

2021, Britz, Alexander, Bokarev, Sergey I., Assefa, Tadesse A., Bajnóczi, Èva G., Németh, Zoltán, Vankó, György, Rockstroh, Nils, Junge, Henrik, Beller, Matthias, Doumy, Gilles, March, Anne Marie, Southworth, Stephen H., Lochbrunner, Stefan, Kühn, Oliver, Bressler, Christian, Gawelda, Wojciech

Time-resolved X-ray absorption spectroscopy has been utilized to monitor the bimolecular electron transfer in a photocatalytic water splitting system. This has been possible by uniting the local probe and element specific character of X-ray transitions with insights from high-level ab initio calculations. The specific target has been a heteroleptic [IrIII (ppy)2 (bpy)]+ photosensitizer, in combination with triethylamine as a sacrificial reductant and Fe3(CO)12 as a water reduction catalyst. The relevant molecular transitions have been characterized via high-resolution Ir L-edge X-ray absorption spectroscopy on the picosecond time scale and restricted active space self-consistent field calculations. The presented methods and results will enhance our understanding of functionally relevant bimolecular electron transfer reactions and thus will pave the road to rational optimization of photocatalytic performance.