A Radical Clock for Reactions of Epoxy Derivatives Induced by Titanocene Chloride

Abstract

[EN]A new radical clock based on pinene derivatives has been designed to measure the radical cyclization rate onto cyano and carbonyl groups and the radical elimination rate of OR and CN. In this system, the known rate constant of cyclobutylcarbinyl radical cleavage is used as the internal clock. At room temperature, the cyclization rate constants for 4-exo and 5-exo processes onto nitrile and aldehyde carbonyl groups are in the order of 107 to 108 s-¹. The radical elimination rate constants for CN, OH, OCHO, and OAc are in the order of 105 to 108 s-¹.