In-situ study of substrate – catalyst interactions in a Juliá–Colonna epoxidation using quartz crystal microbalance with dissipation

Quartz crystal microbalance with dissipation (QCM-D) analysis of the hexa-l-Leucine (PLL)-catalyzed epoxidation of chalcone gives in-situ experimental evidences which demonstrate that the reaction proceeds mainly via the formation of a PLL-bound hydroperoxide complex followed by the reversible addition of chalcone. The observations offer an alternative rationalization for the viability of the preferred catalytic pathway.