Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published May 4, 2018 | Supplemental Material + Accepted Version
Journal Article Open

An Initiation Kinetics Prediction Model Enables Rational Design of Ruthenium Olefin Metathesis Catalysts Bearing Modified Chelating Benzylidenes


Rational design of second-generation ruthenium olefin metathesis catalysts with desired initiation rates can be enabled by a computational model that is dependent on a single thermodynamic parameter. Using a computational model with no assumption about the specific initiation mechanism, the initiation kinetics of a spectrum of second-generation ruthenium olefin metathesis catalysts bearing modified chelating ortho-alkoxy benzylidenes were predicted in this work. Experimental tests of the validity of the computational model were achieved by the synthesis of a series of ruthenium olefin metathesis catalysts and investigation of initiation rates by ultraviolet–visible light (UV-vis) kinetics, nuclear magnetic resonance (NMR) spectroscopy, and structural characterization by X-ray crystallography. Included in this series of catalysts were 13 catalysts bearing alkoxy groups with varied steric bulk on the chelating benzylidene, ranging from ethoxy to dicyclohexylmethoxy groups. The experimentally observed initiation kinetics of the synthesized catalysts were in good accordance with computational predictions. Notably, the fast initiation rate of the dicyclohexylmethoxy catalyst was successfully predicted by the model, and this complex is believed to be among the fastest initiating Hoveyda–Grubbs-type catalysts reported to date. The compatibility of the predictive model with other catalyst families, including those bearing alternative N-heterocyclic carbene (NHC) ligands or disubstituted alkoxy benzylidenes, was also examined.

Additional Information

© 2018 American Chemical Society. Received: March 2, 2018; Revised: March 30, 2018; Published: April 10, 2018. We acknowledge Dr. Bruce S. Brunschwig for assistance with the UV-vis kinetics experiments, which were carried out at the Molecular Materials Research Center of the Beckman Institute at Caltech. The research described in this manuscript was supported financially by the ONR (Award No. N00014-14-1-0650) and the NIH NIGMS (No. F32GM108145, postdoctoral fellowship to K.M.E.). The Bruker KAPPA APEXII X-ray diffractometer was purchased via an NSF CRIF:MU award to the California Institute of Technology (No. CHE-0639094). We thank Materia, Inc. for the generous donation of catalysts 2–5, 33, 36, and 39. Calculations were performed on supercomputers from the DoD HPCMP Open Research Systems and the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by the NSF. Dr. Tzu-Pin Lin, Dr. Crystal K. Chu and Dr. Timothy P. Montgomery are acknowledged for helpful discussions and assistance with NMR experiments. The authors declare no competing financial interest.

Attached Files

Accepted Version - nihms-1032688.pdf

Supplemental Material - cs8b00843_si_001.pdf

Supplemental Material - cs8b00843_si_002.zip


Files (30.3 MB)
Name Size Download all
13.2 MB Preview Download
15.8 MB Preview Download
1.3 MB Preview Download

Additional details

August 19, 2023
October 18, 2023