P-Chiral Ferrocenephospholanes: Synthesis, Reactivity, Metal Complex Chemistry and Application in the Asymmetric Hydrogenation of Olefins

Starting from (R)-N,N-dimethyl-1-ferrocenylethylamine, a diastereoselective ortho-lithiation procedure and a stereoconvergent intramolecular hydrophosphination gave access to P-chiral ferrocenephospholanes. These mono- or bidentate ligands were converted to the corresponding rhodium and iridium complexes, including a chiral version of Crabtree's catalyst, and tested in the asymmetric hydrogenation of functionalized and unfunctionalized olefins. A significant reactivity difference between the rhodium-1,5-cyclooctadiene and the rhodium-norbornadiene complex was observed during catalyst activation.