title: Palladium-Catalyzed C8-Selective C-H Arylation of QuinolineN-Oxides: Insights into the Electronic, Steric and Solvation Effects on the Site-Selectivity by Mechanistic and DFT Computational Studies.
abstract: We report herein a palladium-catalyzed C-H arylation of quinolineN-oxides that proceeds with high selectivity in favor of the C8-isomer. This site-selectivity is unusual for palladium, since all of the hitherto described methods of palladium-catalyzed C-H functionalization of quinolineN-oxides are highly C2-selective. The reaction exhibits a broad synthetic scope with respect to quinolineN-oxides and iodoarenes and can be significantly accelerated to sub-hour reaction times under microwave irradiation. The C8-arylation method can be carried out on gram scale and has excellent functional group tolerance. Mechanistic and Density Functional Theory (DFT) computational studies provide evidence for the cyclopalladation pathway and describe key parameters influencing the site-selectivity.
authors.affiliation: Department of Chemistry, University of Texas at San Antonio, San Antonio, Texas 78249, United States.
authors.forename: David E
authors.initials: DE
authors.lastname: Stephens
authors.affiliation: Department of Chemistry, University of Texas at San Antonio, San Antonio, Texas 78249, United States ; Centre for Biodiversity and Drug Discovery, Institute for Scientific Research and High Technology Services, Panama City, Republic of Panama ; Department of Biotechnology, Acharya Nagarjuna University, Nagarjuna Nagar, India.
authors.forename: Johant
authors.initials: J
authors.lastname: Lakey-Beitia
authors.affiliation: Department of Chemistry, University of Texas-Pan American, Edinburg, Texas 78539, United States.
authors.forename: Abdurrahman C
authors.initials: AC
authors.lastname: Atesin
authors.affiliation: Department of Chemistry, University of Texas-Pan American, Edinburg, Texas 78539, United States.
authors.forename: Tülay A
authors.initials: TA
authors.lastname: Ateşin
authors.affiliation: Department of Chemistry, University of Texas at San Antonio, San Antonio, Texas 78249, United States.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Chavez
authors.affiliation: Department of Chemistry, University of Texas at San Antonio, San Antonio, Texas 78249, United States.
authors.forename: Hadi D
authors.initials: HD
authors.lastname: Arman
authors.affiliation: Department of Chemistry, University of Texas at San Antonio, San Antonio, Texas 78249, United States.
authors.forename: Oleg V
authors.initials: OV
authors.lastname: Larionov