title: Rapid assembly of functionalised spirocyclic indolines by palladium-catalysed dearomatising diallylation of indoles with allyl acetate.
abstract: Herein, we report the application of allyl acetate to the palladium-catalysed dearomatising diallylation of indoles. The reaction can be carried out by using a readily available palladium catalyst at room temperature, and can be applied to a wide range of substituted indoles to provide access to the corresponding 3,3-diallylindolinines. These compounds are versatile synthetic intermediates that readily undergo Ugi reactions or proline-catalysed asymmetric Mannich reactions. Alternatively, acylation of the 3,3-diallylindolinines with an acid chloride or a chloroformate, followed by treatment with aluminium chloride, enables 2,3-diallylindoles to be prepared. By using ring-closing metathesis, functionalised spirocyclic indoline scaffolds can be accessed from the Ugi products, and a dihydrocarbazole can be prepared from the corresponding 2,3-diallylindole.
authors.affiliation: Department of Chemistry, University College London, 20 Gordon St, London, WC1H 0AJ (UK).
authors.forename: Persis
authors.initials: P
authors.lastname: Dhankher
authors.forename: Laure
authors.initials: L
authors.lastname: Benhamou
authors.forename: Tom D
authors.initials: TD
authors.lastname: Sheppard
mesh_terms: D000085:Acetates / Q000737:chemistry*; D000215:Acylation; D000498:Allyl Compounds / Q000737:chemistry*; D002227:Carbazoles / Q000138:chemical synthesis / Q000737:chemistry; D002384:Catalysis; D007211:Indoles / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D013141:Spiro Compounds / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000085:Acetates; D000498:Allyl Compounds; D002227:Carbazoles; D007211:Indoles; D013141:Spiro Compounds; D010165:Palladium; C498551:allyl acetate
keywords: allylation; heterocycles; homogeneous catalysis; indoles; palladium