title: Synthesis of (±)-Tetrabenazine by Visible Light Photoredox Catalysis.
abstract: (±)-Tetrabenazine was synthesized in six steps from commercially available compounds. The key cyclization substrate was assembled rapidly via Baylis-Hillman and aza-Michael reactions. Annulation of the final ring was achieved through visible light photocatalysis, wherein carbon-carbon bond formation was driven by the oxidation of a tertiary amine. Solvent played a critical role in the photoredox cyclization outcome, whereas methanol led to a mixed ketal, acetonitrile/water (10:1) gave direct cyclization to (±)-tetrabenazine and occurred more rapidly.
authors.affiliation: Department of Chemistry, Hendrix College , 1600 Washington Avenue, Conway, Arkansas 72032, United States.
authors.forename: Lindsey R
authors.initials: LR
authors.lastname: Orgren
authors.affiliation: Department of Chemistry, Hendrix College , 1600 Washington Avenue, Conway, Arkansas 72032, United States.
authors.forename: Emily E
authors.initials: EE
authors.lastname: Maverick
authors.affiliation: Department of Chemistry, Hendrix College , 1600 Washington Avenue, Conway, Arkansas 72032, United States.
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Marvin
mesh_terms: D002384:Catalysis; D003500:Cyclization; D008027:Light; D015394:Molecular Structure; D010084:Oxidation-Reduction; D055668:Photochemical Processes; D013747:Tetrabenazine / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D013747:Tetrabenazine