Computational Studies of Ruthenium‐Catalyzed Olefin Metathesis

Abstract

Computations have become an important tool to study organometallic reactions, and have been applied to investigate many aspects of ruthenium-catalyzed olefin metathesis. In this chapter, we summarize some of the most important theoretical insights from more than 100 computational studies reported in the past 10 years. We first focus on the general mechanisms for catalyst initiation and propagation associated with phosphine- and N-heterocyclic carbene (NHC)-ligated catalysts. The effects of the spectator ligands on reactivity, phosphine, and olefin binding energies, and the stability of the metallacyclobutane are then discussed. Next, investigations related to E/Z-selectivity and reactivity of substituted olefins with second-generation Grubbs catalysts are addressed. After these general discussions, we discuss key findings related to special types of metathesis processes (ring-opening, ring-closing, and enyne metathesis). Undesired side reactions, including catalyst decomposition and alkene isomerization, are also addressed. Recent computational studies have shown that Z-selective olefin metathesis reaction using chelated ruthenium catalysts involves a unique side-bound mechanism and catalyst control of the stereoselectivities. The mechanism, selectivities, and decomposition pathways of these Z-selective catalysts are summarized. Finally, we address the accuracy of the different theoretical methods commonly used in olefin metathesis computations.