title: Synthesis of 3,3'-spirocyclic oxindoles via phosphine catalyzed [4 + 2] cyclizations.
abstract: Triphenylphosphine promoted reactions between 3-arylideneoxindoles and δ-aryl-substituted penta-2,3-dienoates afford an unprecedented access to spirocyclic oxindoles with functionalized six-membered rings. In these new [4 + 2] cyclization processes, the allenoates operate as the four-carbon synthons, thanks to the involvement of the substituted δ-carbons. These reactions give excellent control of the relative stereochemistry of the three stereogenic centers. The stereochemistry of the final product has been ascertained by X-ray diffraction studies.
authors.affiliation: Institut de Chimie des Substances Naturelles, CNRS UPR 2301 - Centre de Recherche de Gif -1, avenue de la Terrasse, 91198 Gif-sur-Yvette, France.
authors.forename: Maxime
authors.initials: M
authors.lastname: Gicquel
authors.forename: Catherine
authors.initials: C
authors.lastname: Gomez
authors.forename: Pascal
authors.initials: P
authors.lastname: Retailleau
authors.forename: Arnaud
authors.initials: A
authors.lastname: Voituriez
authors.forename: Angela
authors.initials: A
authors.lastname: Marinetti
mesh_terms: D002384:Catalysis; D003500:Cyclization; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D009943:Organophosphorus Compounds / Q000737:chemistry*; D000078183:Oxindoles; D010720:Phosphines / Q000737:chemistry*; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D014961:X-Ray Diffraction
chemical_list: D007211:Indoles; D009943:Organophosphorus Compounds; D000078183:Oxindoles; D010720:Phosphines; D013141:Spiro Compounds; C022960:2-oxindole; C061896:triphenylphosphine; C044646:phosphine