Palladacycles with Palladium-Bonded Stereogenic Carbons: Tools for Exploring Reaction Pathways in Organometallic Chemistry

Abstract

While reactions with organopalladium intermediates often give useful organic products, little is known about how the ligand sphere impacts the reactivity of these intermediates. To explore the interactions between the auxiliary ligand and the other substitutents on the metal center, we performed synthetic and structural studies on both polymer-bound palladacycles and a new organometallic scaffold, the palladapyrrolidinone. In the case of palladacycles on solid-phase, we observed that the precise characteristics of the polymer-bound ligand had a large impact on the reactivity of the complex. In the case of the palladapyrrolidinones, we observed that the shape and size of the ligand sphere had a large impact on the diastereoselective formation of a sp3-C stereocenter bound to a palladium center. We found that a chiral non-racemic ligand had little impact on the stereoselectivity. In conclusion, the ligand sphere has a distinct impact on both the reactivity and stereoselectivity of reactions involving palladacycles.