Speaker: Sondre Eliasson
Title: Automated De Novo Design of Olefin Metathesis Catalysts: Testing Rational Design Criterion
Abstract: Automated design of Grubbs’s style olefin metathesis catalysts was used to test a rational design criterion: the shorter the Ru=CH2 bond in the 14-electron intermediate, the more efficient the catalyst (J. Am. Chem. Soc. 2006, 128, 6952–6964). Dative N-heterocyclic carbene (NHC) ligands (L) were automatically generated and modified to obtain the shortest Ru=CH2 bond in the trans-di-chloride 14-electron intermediate LRu(Cl)2(=CH2) as modelled by density functional theory. In addition to structural variations on known NHC ligands, the automated design identified novel molecular strategies that induce shortening of the Ru=CH2 bond. Computational testing also predicted high activity for the generated candidates with short bond-length. However, experimental validation of one of the promising ligands identified problems related to the synthesizability and stability of the catalyst, thus highlighting the limited applicability of a catalyst design criterion based solely on the Ru=CH2.bondlenght. This suggests that developing catalyst design criteria that also consider the capability of accessing the catalyst precursor experimentally and the catalyst stability during the reaction is of critical importance.