title: Indole Synthesis via Cyclative Formation of 2,3-Dizincioindoles and Regioselective Electrophilic Trapping.
abstract: Upon zincation of two acidic protons attached to the nitrogen and the sp-carbon atoms, a N-protected 2-ethynylaniline cyclizes to a 2,3-dizincioindole at 120 °C. Driven by the energy gain due to formation of two C-Zn bonds, this reaction occurs smoothly without side reactions, although this transformation is intrinsically endothermic in its bare anionic form. The resulting dizinc intermediate can be functionalized with one or two different electrophiles either inter- or intramolecularly on either C2or C3selectively, depending on the choice of catalyst and the electrophiles. This conversion of 2-ethynylaniline to 2,3-dimetalloindole can be applied to an expeditious synthesis of indenoindolone and benzodipyrrole derivatives, which are compounds of interest for medicinal chemistry and materials science, respectively.
authors.affiliation: Department of Chemistry and Molecular Technology Innovation Chair, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Laurean
authors.initials: L
authors.lastname: Ilies
authors.affiliation: Department of Chemistry and Molecular Technology Innovation Chair, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Mayuko
authors.initials: M
authors.lastname: Isomura
authors.affiliation: Department of Chemistry and Molecular Technology Innovation Chair, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Shin-Ichi
authors.initials: SI
authors.lastname: Yamauchi
authors.affiliation: Department of Chemistry and Molecular Technology Innovation Chair, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Tomoya
authors.initials: T
authors.lastname: Nakamura
authors.affiliation: Department of Chemistry and Molecular Technology Innovation Chair, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Eiichi
authors.identifier: 0000-0002-4192-1741
authors.initials: E
authors.lastname: Nakamura