title: Stereoconvergent arylations and alkenylations of unactivated alkyl electrophiles: catalytic enantioselective synthesis of secondary sulfonamides and sulfones.
abstract: The development of efficient methods for the generation of enantioenriched sulfonamides and sulfones is an important objective for fields such as organic synthesis and medicinal chemistry; however, there have been relatively few reports of direct catalytic asymmetric approaches to controlling the stereochemistry of the sulfur-bearing carbon of such targets. In this report, we describe nickel-catalyzed stereoconvergent Negishi arylations and alkenylations of racemic α-bromosulfonamides and -sulfones that furnish the desired cross-coupling product in very good ee and yield for an array of reaction partners. Mechanistic studies are consistent with the generation of a radical intermediate that has a sufficient lifetime to diffuse out of the solvent cage and to cyclize onto a pendant olefin.
authors.affiliation: Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Junwon
authors.initials: J
authors.lastname: Choi
authors.forename: Pablo
authors.initials: P
authors.lastname: Martín-Gago
authors.forename: Gregory C
authors.initials: GC
authors.lastname: Fu
mesh_terms: D000473:Alkanes / Q000737:chemistry*; D000475:Alkenes / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D004579:Electron Transport; D006841:Hydrocarbons, Aromatic / Q000138:chemical synthesis* / Q000737:chemistry; D009532:Nickel; D009942:Organometallic Compounds / Q000737:chemistry; D013237:Stereoisomerism; D013449:Sulfonamides / Q000138:chemical synthesis* / Q000737:chemistry; D013450:Sulfones / Q000138:chemical synthesis / Q000737:chemistry; D015032:Zinc / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
chemical_list: D000473:Alkanes; D000475:Alkenes; D006841:Hydrocarbons, Aromatic; D009942:Organometallic Compounds; D013449:Sulfonamides; D013450:Sulfones; D009532:Nickel; D015040:Zirconium; D015032:Zinc