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Updated: Jul 10, 2025
08:46
Preparation and Reactivity of a Triphosphenium Bromide Salt: A Convenient and Stable Source of PhosphorusI
Published on: November 22, 2016
7.8K
Stabilization of sp-Hybridized Nitrogen Cation by Lewis Acid-Base Complex Formation with Intramolecular Iodine
Tomohiro Fujino1, Tadashi Hyodo2, Yuko Otani1
1Department of Organic and Medicinal Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|November 20, 2023
Summary
A novel sp-hybridized nitrogen cation, stabilized by iodine, forms hypervalent iodine(III) compounds. This stable N-I bonded cation acts as a Lewis acid and a reagent for ketone α-oxidation.
Area of Science:
- Organic Chemistry
- Hypervalent Iodine Chemistry
Background:
- The stabilization of sp-hybridized nitrogen cations is challenging.
- Peri-iodine substituents offer unique electronic effects in organic systems.
Purpose of the Study:
- To synthesize and characterize a novel sp-hybridized nitrogen cation stabilized by a peri-iodine substituent.
- To explore the reactivity of this cation as a Lewis acid and a synthetic reagent.
Main Methods:
- Isolation and characterization of the nitrogen-iodine bonded cation as a tetrafluoroborate salt.
- Experimental techniques: 1H NMR spectroscopy and X-ray structure analysis.
- Theoretical calculations: Density Functional Theory (DFT) methods.
Main Results:
- The sp-hybridized nitrogen cation is strongly stabilized by a peri-iodine substituent in a tetralone system.
- The cation forms hypervalent iodine(III) compounds with a short N-I bond, acting as a Lewis acid.
- The N-I bonded cation is intrinsically stable and can be employed for the α-oxidation of ketones.
Conclusions:
- A stable sp-hybridized nitrogen cation featuring a peri-iodine substituent has been successfully synthesized and characterized.
- This cation exhibits unique Lewis acidity and serves as a valuable reagent in organic synthesis, particularly for ketone oxidation.
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