The search for better catalysts for imine hydrogenation is an ongoing challenge. Understanding of the underlying mechanism can play an important role in the evolution of catalyst design. The goal of this research is to get more insight in the asymmetric hydrogenation (AH) of 2-Methyl-1-pyrroline with an Ir-based catalyst with a phosphorous bidentate ligand (JosiPhos) using density functional theory (DFT) calculations. In this research, two mechanisms are investigated. The inner sphere C-migration mechanism is explored for all possible options for the coordination of the substrate to the catalyst complex. A conformer search with Conformer–Rotamer Ensemble Sampling Tool (CREST) is done on three transition states (TS) to investigate if ensemble representations are important for the determination of the enantioselectivity of a certain path. The outer sphere mechanism is only partially explored. Using DFT, the energy landscape of each reaction path could be mapped out.

Of the inner sphere C-migration mechanism, ten possible reaction paths were obtained. The two most thermodynamically favourable paths are the paths where the substrate binds on one specific equatorial coordination site. There is no substantial preference for the formation of one enantiomer over the other. However, CREST calculations generated possible conformers of certain transition states, some with a lower energy. This resulted in a preference for the formation of the R-enantiomer for the inner sphere C-migration mechanism.

Little can be said about the outer sphere mechanism since there is not enough data yet to form a clear conclusion about the favourability of this mechanism. One of the findings was that another type of outer sphere mechanism was found other than the outer sphere mechanism proposed based on literature. To be able to state what mechanism is the most likely to occur, more quantitative research is needed on the outer sphere mechanism and other possible mechanisms.