Experimental and Computational Study of the ( Z)-Selective Formation of Trisubstituted Olefins and Benzo-Fused Oxacycles from the Ruthenium-Catalyzed Dehydrative C-H Coupling of Phenols with Ketones. J Am Chem Soc 2018 Aug 15;140(32):10289-10296
Date
07/24/2018Pubmed ID
30032611Pubmed Central ID
PMC6558961DOI
10.1021/jacs.8b05875Scopus ID
2-s2.0-85050763111 (requires institutional sign-in at Scopus site) 29 CitationsAbstract
The cationic Ru-H complex was found to be an effective catalyst for the dehydrative C-H coupling of phenols with ketones to form the trisubstituted olefin products. The coupling of phenol with linear ketones led to highly stereoselective formation of the ( Z)-olefin products. The dehydrative coupling of phenol with enones and diones efficiently formed the benzopyrene and related oxacyclic derivatives. The reaction of 3,5-dimethoxyphenol with cyclohexanone-2,2,6,6- d4 showed a significant H/D exchange to both vinyl and α-CH2 positions on the olefin product (72-75% D). A significant carbon isotope effect was observed on the ortho-arene carbon of the olefin product. The free energies of intermediate species for the entire catalytic cycle were successfully computed by using the DFT method. The DFT study revealed that the E/ Z stereoselectivity is a result of the energy difference in the insertion step of ortho-metalated phenol to an enol form of the ketone substrate (ΔΔ E = 9.6 kcal/mol). The coupling method provides a direct catalytic C-H olefination method for ketones to form trisubstituted olefins without employing any reactive reagents or forming any wasteful byproducts.
Author List
Lee H, Mane MV, Ryu H, Sahu D, Baik MH, Yi CSAuthor
Chae Yi PhD Professor, Inorganic and Organometallic Chemistry, Homogeneous Catalysis in the Chemistry department at Marquette UniversityMESH terms used to index this publication - Major topics in bold
AlkenesCatalysis
Computer Simulation
Ketones
Models, Molecular
Molecular Structure
Phenols
Ruthenium
