Mechanistic Studies of the Deoxydehydration of Polyols Catalyzed by a Mo(VI) Dioxo(pyridine-2,6-dicarboxylato) Complex
by Tran, R.; Canote, C. A.; Kilyanek, S. M.
The need for renewable resources to displace petrochemical feedstocks is of great interest. Deoxydehydration (DODH) reduces biomass -derived polyols and diols to alkenes and dienes, possibly moving alkene production closer to carbon-neutral sources. We report the DODH of numerous aromatic, aliphatic, and biomass model diols by a dioxo-Mo(VI) catalyst, MoO2(pyridine-2,6-dicarboxylato)(HMPA). Optimal reaction conditions were found using PPh3 and 1-phenyl-1,2-ethanediol yielding up to 93% styrene. Mechanistic studies using in situ infrared spectroscopy support a biexponential kinetic regime where the rate constant of the rate-determining step is similar to 5 x 10-5 s-1. DFT calculations support the kinetic studies and suggest that the largest kinetic barrier is a proton transfer from the substrate to a metal-oxo bond during diolate formation.
- Journal
- Organometallics
- Volume
- 42
- Issue
- 11
- Year
- 2023
- Start Page
- 1190-1197
- URL
- https://dx.doi.org/10.1021/acs.organomet.3c00001
- ISBN/ISSN
- 1520-6041; 0276-7333
- DOI
- 10.1021/acs.organomet.3c00001