Helicenes as Chirality-Inducing Groups in Transition-Metal Catalysis: The First Helically Chiral Olefin Metathesis Catalyst

0492362 - ÚOCHB 2019 RIV DE eng J - Článek v odborném periodiku
Karras, Manfred - Dabrowski, M. - Pohl, Radek - Rybáček, Jiří - Vacek, Jaroslav - Bednárová, Lucie - Grela, K. - Starý, Ivo - Stará, Irena G. - Schmidt, B.
Helicenes as Chirality-Inducing Groups in Transition-Metal Catalysis: The First Helically Chiral Olefin Metathesis Catalyst.
Chemistry - A European Journal. Roč. 24, č. 43 (2018), s. 10994-10998. ISSN 0947-6539. E-ISSN 1521-3765
Grant CEP: GA ČR(CZ) GA16-08294S
Institucionální podpora: RVO:61388963
Klíčová slova: asymmetric catalysis * carbene ligands * helicenes * metathesis * ruthenium
Obor OECD: Organic chemistry
Impakt faktor: 5.160, rok: 2018

Helical chirality is a novel enantioselectivity-inducing property in transition-metal-catalyzed transformations. The principle is illustrated herein for the example of asymmetric olefin metathesis. This work reports the synthesis of the first helically chiral Ru-NHC alkylidene complex from an aminohelicene-derived imidazolium salt, which was ligated to the first generation Hoveyda-Grubbs catalyst. Kinetic data were acquired for benchmark test reactions and compared to an achiral catalyst. The helically chiral Ru-catalyst was evaluated in asymmetric ring-closing metathesis (RCM) and ring-opening metathesis-cross-metathesis (ROM/CM) reactions, which proceeded with promising levels of enantioselectivity. Extensive NMR-spectroscopic investigations and a DFT geometry optimization were performed. These results led to a topographic steric map and calculation of percent-buried-volume values for each quadrant around the metal center.
Trvalý link: http://hdl.handle.net/11104/0285921