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Formal Halogen Transfer of Bromoarenes via Stepwise Reactions
Kengo Inoue1, Atsunori Mori1,2, Kentaro Okano1
1Department of Chemical Science and Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan.
Organic Letters
|August 30, 2023
Summary
This study presents a two-step method for halogen transfer in bromoarenes. It enables the synthesis of polybrominated arenes and the regioselective translocation of bromine atoms in various aromatic compounds.
Area of Science:
- Organic Chemistry
- Synthetic Methodology
Background:
- Bromoarenes are versatile building blocks in organic synthesis.
- Efficient methods for polybromination and halogen repositioning are crucial.
Purpose of the Study:
- To develop a novel two-step halogen transfer strategy for bromoarenes.
- To synthesize di-, tri-, and tetrabromoarenes.
- To achieve regioselective bromine translocation in heterocyclic compounds.
Main Methods:
- Deprotonative lithiation of bromoarenes to form bromoaryllithiums.
- In situ zincation to generate organozinc species.
- Subsequent bromination to yield polybrominated arenes.
- Bromine-magnesium exchange followed by electrophilic trapping for halogen translocation.
Main Results:
- Synthesis of di-, tri-, and tetrabromoarenes with yields ranging from 41-95%.
- Regioselective translocation of bromine in benzene, pyridine, quinoline, pyrimidine, and thiazole derivatives (28-86% yields).
Conclusions:
- The reported two-step halogen transfer is an effective method for synthesizing polybrominated arenes.
- The strategy allows for controlled repositioning of bromine atoms in diverse aromatic systems.
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