title: Organophotocatalysis: Insights into the Mechanistic Aspects of Thiourea-Mediated Intermolecular [2+2] Photocycloadditions.
abstract: Mechanistic investigations of the intermolecular [2+2] photocycloaddition of coumarin with tetramethylethylene mediated by thiourea catalysts reveal that the reaction is enabled by a combination of minimized aggregation, enhanced intersystem crossing, and altered excited-state lifetime(s). These results clarify how the excited-state reactivity can be manipulated through catalyst-substrate interactions and reveal a third mechanistic pathway for thiourea-mediated organo-photocatalysis.
authors.affiliation: Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND, 58108-6050, USA.
authors.forename: Nandini
authors.initials: N
authors.lastname: Vallavoju
authors.affiliation: Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND, 58108-6050, USA.
authors.forename: Sermadurai
authors.initials: S
authors.lastname: Selvakumar
authors.affiliation: Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND, 58108-6050, USA.
authors.forename: Barry C
authors.initials: BC
authors.lastname: Pemberton
authors.affiliation: Department of Chemistry, Columbia University, New York, NY, 10025, USA.
authors.forename: Steffen
authors.initials: S
authors.lastname: Jockusch
authors.affiliation: Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND, 58108-6050, USA. mukund.sibi@ndsu.edu.
authors.forename: Mukund P
authors.initials: MP
authors.lastname: Sibi
authors.affiliation: Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND, 58108-6050, USA. jayaraman.sivaguru@ndsu.edu.
authors.forename: Jayaraman
authors.identifier: 0000-0002-0446-6903
authors.initials: J
authors.lastname: Sivaguru
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D002384:Catalysis; D003374:Coumarins / Q000737:chemistry*; D061565:Cycloaddition Reaction; D008027:Light; D008958:Models, Molecular; D055668:Photochemical Processes; D013890:Thiourea / Q000737:chemistry*
chemical_list: D000475:Alkenes; D003374:Coumarins; C040216:2,3-dimethyl-2-butene; C030123:coumarin; D013890:Thiourea
keywords: asymmetric catalysis; organocatalysis; photochemistry; photocycloadditions; thioureas