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Updated: Oct 10, 2025

Synthesis of Hypervalent Iodonium Alkynyl Triflates for the Application of Generating Cyanocarbenes
Published on: September 8, 2013
Anhydrous Hydrogen Iodide-Mediated Reductive Indolization of In Situ-Generated Cyclopropyl Hydrazones
Motohiro Yasui1, Hiroki Fujioka1, Norihiko Takeda1
1Kobe Pharmaceutical University, Motoyamakita, Higashinada, Kobe 658-8558, Japan.
Abstract:
Fischer-type indolization of N-aryl-C-cyclopropyl hydrazones generated in situ followed by chemoselective reduction using tert-butyl iodide as an anhydrous HI generator was developed. This protocol provides indoles bearing carboxylic acid derivative units. A series of control experiments indicated the HI-mediated formation and reduction of spirocyclopropyl indolenines. Anhydrous HI functions as a Brønsted acid as well as a reducing agent, facilitating the successful conversion of unstable reaction intermediates and iodinated mixtures in equilibrium.
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