New ruthenium-​based catalysts for Z-​selective metathesis of hindered olefins

Abstract

A series of new ruthenium-based metathesis catalysts with varying N-heterocyclic carbene (NHC) substituents and their reactivity toward hindered olefins are reported. Through systematic variation of the sterics and electronics of the NHC substituents, metathesis activity and Z-selectivity are related to structure, resulting in catalysts that perform cross metathesis of a wide variety of allylic-substituted olefins in high yield and excellent Z-selectivity. Further insights into reactivity are obtained from the solid-state structures and soln. dynamics of the catalysts.