Synthesis of Rhodium Complexes with Chiral Diene Ligands via Diastereoselective Coordination and Their Application in the Asymmetric Insertion of Diazo Compounds into E−H Bonds
Nikita M. Ankudinov, Denis Chusov, Yulia V. Nelyubina, Dmitry S. Perekalin
Abstract
Abstract A new method for the synthesis of chiral diene rhodium catalysts is introduced. The readily available racemic tetrafluorobenzobarrelene complexes [(R 2 ‐TFB)RhCl] 2 were separated into two enantiomers via selective coordination of one of them with the auxiliary S ‐salicyl‐oxazoline ligand. One of the resulting chiral complexes with an exceptionally bulky diene ligand [( R , R ‐ i Pr 2 ‐TFB)RhCl] 2 was an efficient catalyst for the asymmetric insertion of diazoesters into B−H and Si−H bonds giving the functionalized organoboranes and silanes with high yields (79–97 %) and enantiomeric purity (87–98 % ee ). The stereoselectivity of separation via auxiliary ligand and that of the catalytic reaction was predicted by DFT calculations.