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Updated: Jun 27, 2026

A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis
Published on: February 16, 2020
cis-Selective Direct Halocyclopropanation of Alkenes Mediated by Nucleophilic Cobalt Photocatalysis
John Hayford G Teye-Kau1, Martin Pauze1, Spencer P Pitre1
1Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078, United States.
Abstract:
The cyclopropyl group is an invaluable motif in both medicinal and synthetic chemistry, with 1,2-disubstituted halocyclopropanes serving as important building blocks for the preparation of more complex cyclopropane-containing structures. Herein, we report a Vitamin B12-photocatalyzed approach for the direct synthesis of 1,2-disubstituted halocyclopropanes, starting from alkenes and simple haloforms under visible-light irradiation. Our method yields a diverse range of 1,2-disubstituted halocyclopropanes with high cis-selectivity, providing efficient access to these traditionally difficult-to-prepare stereoisomers. Mechanistic studies highlight the crucial role of Vitamin B12 in influencing the stereochemical outcome of the reaction.
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