Quantum mechanical calculations on the mechanism of olefin metathesis with a variety of substituents mediated by a Ru alkylidene catalyst reveal multistep processes along the general reactants → adduct → coordination complex → metallacycle → decoordination complex → products pathway for two consecutive turnovers. Net energy barriers in solution do not exceed 12 kcal mol −1 during the [Ru]The complex series of steps is initially driven by the evolution of the Ru(catalyst)•••C(olefin) contact. Dissection of bonding interactions using the tools provided by the natural bond orbitals and by the quantum theory of atoms in molecules methods indicate that each contact in the Ru(catalystcyclic reactive center undergoes the following series of transformations in different orders: no interaction → long range → σ → → π. Every single contact in this reactive center gains/loses an entire σ bond during the •••TS → metallacycle → TS••• interval. The lowest point in the potential energy surface is usually the metallacycle. For the first turnover, cycloreversion and final elimination of the products exhibit late transition states leading to higher relative energy barriers. Conversely, for the second turnover, it is the metallacycle to decoordination complex transformation step which leads to the highest barriers, constituting the rate-determining step for the entire process. Each step of the reaction is best described as a highly asynchronous process. Electron-withdrawing groups exhibit the largest overall barriers by virtue of destabilizing the emerging π bond in the final R 1 R 2 CCR 1 R 2 olefin during the second turnover.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.