title: Enantioselective synthesis of polycyclic carbocycles via an alkynylation-allylation-cyclization strategy.
abstract: A new general three-stage strategy to access polycyclic ring systems bearing all-carbon quaternary centers with high enantioselectivity is reported. The required starting materials were readily accessed in racemic form through the α-alkynylation of ketoesters with EBX (EthynylBenziodoXolone) hypervalent iodine reagents. A Pd-catalyzed asymmetric decarboxylation allylation was then achieved in high yields and enantioselectivities with Trost's biphosphine ligands. Finally, transition-metal catalyzed cyclization of the obtained chiral enynes gave access to fused and spiro polycyclic ring systems constituting the core of many bioactive natural products.
authors.affiliation: Laboratory of Catalysis and Organic Synthesis, Ecole Polytechnique Fédérale de Lausanne, EPFL SB ISIC LCSO , BCH 4306, 1015 Lausanne, Switzerland.
authors.forename: Maria Victoria
authors.initials: MV
authors.lastname: Vita
authors.forename: Pascal
authors.initials: P
authors.lastname: Mieville
authors.forename: Jerome
authors.initials: J
authors.lastname: Waser
mesh_terms: D001583:Benzoxazoles / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D007202:Indicators and Reagents / Q000737:chemistry; D007455:Iodine / Q000737:chemistry; D008024:Ligands; D015394:Molecular Structure; D011083:Polycyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D001583:Benzoxazoles; D007202:Indicators and Reagents; D008024:Ligands; D011083:Polycyclic Compounds; D007455:Iodine