Catalytic asymmetric synthesis

Chiral macrocyclic tetra- and hexamine macrocycles in complexes with zinc efficiently catalyze the asymmetric hydrosilylation (AHS) of prochiral ketones and imines with enantiomeric excess of the product up to 100%.

The cyclic structure of the trianglamine ligand and the presence of additional functional groups increased the enantioselectivity of the reaction, in comparison to the catalysis with the acyclic ligands. Density functional theory computations on the structures of ligand-zinc complex together with the possible transition states calculations  allowed to determine the direction of the asymmetric induction in AHS reaction.

Figure 2