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Radical Aryl Migration from Boron to Carbon
Dinghai Wang1, Christian Mück-Lichtenfeld1, Constantin G Daniliuc1
1Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstraße 40, 48149 Münster, Germany.
Journal of the American Chemical Society
|June 21, 2021
Summary
This study introduces radical 1,5-aryl migration from boron to carbon in aryl boronate complexes, a novel organic transformation. This method provides access to diverse arylated products under mild conditions with high diastereoselectivity.
Area of Science:
- Organic Chemistry
- Radical Reactions
- Organoboron Chemistry
Background:
- Radical aryl migration is a known organic transformation involving aryl group migration.
- Previous studies have reported migrations involving elements like N, O, Si, P, S, Sn, Ge, and Se.
- Radical aryl migration from a boron center has not been previously documented.
Purpose of the Study:
- To present the first report of radical 1,5-aryl migration from boron to carbon.
- To demonstrate the utility of this reaction in synthesizing arylated products.
- To explore the scope and mechanism of this novel transformation.
Main Methods:
- Generation of carbon-centered radicals via radical addition onto alkenyl aryl boronate complexes.
- Investigation of 1,5-aryl migration from boron to carbon.
- In situ generation of boronate complexes from alkenylboronic acid esters and aryl lithium reagents.
- Use of DFT calculations to support the proposed mechanism.
Main Results:
- Successful demonstration of radical 1,5-aryl migration from boron to carbon.
- Synthesis of 4-aryl-alkylboronic esters with high diastereoselectivity.
- Facilitation of divergent synthesis by varying the aryl moiety.
- Feasibility of analogous 1,4-aryl shifts.
Conclusions:
- Radical 1,5-aryl migration from boron is a new and efficient synthetic methodology.
- The reaction offers a versatile route to diverse arylated alkylboronic esters.
- The findings expand the scope of known radical aryl migration reactions.
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