title: Gold(I)-Catalyzed Dearomative [2+2]-Cycloaddition of Indoles with Activated Allenes: A Combined Experimental-Computational Study.
abstract: The gold-catalyzed synthesis of methylidene 2,3-cyclobutane-indoles is documented through a combined experimental/computational investigation. Besides optimizing the racemic synthesis of the tricyclic indole compounds, the enantioselective variant is presented to its full extent. In particular, the scope of the reaction encompasses both aryloxyallenes and allenamides as electrophilic partners providing high yields and excellent stereochemical controls in the desired cycloadducts. The computational (DFT) investigation has fully elucidated the reaction mechanism providing clear evidence for a two-step reaction. Two parallel reaction pathways explain the regioisomeric products obtained under kinetic and thermodynamic conditions. In both cases, the dearomative CC bond-forming event turned out to be the rate-determining step.
authors.affiliation: Department of Chemistry "G. Ciamician", Alma Mater Studiorum - University of Bologna, Via Selmi 2, 40126 Bologna (Italy).
authors.forename: Riccardo
authors.initials: R
authors.lastname: Ocello
authors.affiliation: Department of Chemistry "G. Ciamician", Alma Mater Studiorum - University of Bologna, Via Selmi 2, 40126 Bologna (Italy).
authors.forename: Assunta
authors.initials: A
authors.lastname: De Nisi
authors.affiliation: Department of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433 (China).
authors.forename: Minqiang
authors.initials: M
authors.lastname: Jia
authors.affiliation: Department of Chemistry "G. Ciamician", Alma Mater Studiorum - University of Bologna, Via Selmi 2, 40126 Bologna (Italy).
authors.forename: Qing-Qing
authors.initials: QQ
authors.lastname: Yang
authors.affiliation: Department of Chemistry "G. Ciamician", Alma Mater Studiorum - University of Bologna, Via Selmi 2, 40126 Bologna (Italy).
authors.forename: Magda
authors.initials: M
authors.lastname: Monari
authors.affiliation: Department of Chemistry "G. Ciamician", Alma Mater Studiorum - University of Bologna, Via Selmi 2, 40126 Bologna (Italy).
authors.forename: Pietro
authors.initials: P
authors.lastname: Giacinto
authors.affiliation: Department of Chemistry "G. Ciamician", Alma Mater Studiorum - University of Bologna, Via Selmi 2, 40126 Bologna (Italy).
authors.forename: Andrea
authors.initials: A
authors.lastname: Bottoni
authors.affiliation: Department of Chemistry "G. Ciamician", Alma Mater Studiorum - University of Bologna, Via Selmi 2, 40126 Bologna (Italy). gianpietro.miscione@unibo.it.|Department of Chemistry, Universidad de los Andes, Carrera 1 N° 18A 10, Bogotá (Colombia). gianpietro.miscione@unibo.it.
authors.forename: Gian Pietro
authors.initials: GP
authors.lastname: Miscione
authors.affiliation: Department of Chemistry "G. Ciamician", Alma Mater Studiorum - University of Bologna, Via Selmi 2, 40126 Bologna (Italy). marco.bandini@unibo.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Bandini
keywords: allenamide; asymmetric catalysis; density functional calculations; gold; indole