Borocyclopropanation of Styrenes Mediated by UV‐light Under Continuous Flow Conditions |
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| Authors: | Morgane Sayes Guillaume Benoit Prof André B Charette |
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| Affiliation: | Faculty of Arts and Sciences, Department of Chemistry, Université de Montreal, Montreal, Quebec, Canada |
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| Abstract: | Herein, we report a user‐friendly and metal‐free UV‐A light mediated borocyclopropanation of styrenes using continuous flow technology. A broad range of styrene derivatives can be cyclopropanated in good yields within 1 h residence time to produce highly valuable cyclopropylboronate esters with modest to good diastereoselectivities. The reaction is also applicable to α‐substituted styrenes. Mechanistic studies support a photoredox process during which xanthone, a well‐known organic photosensitizer, can easily reach a photoexcited state that is available for both an oxidative and a reductive quenching. |
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| Keywords: | borocyclopropanes continuous flow photochemistry radicals UV-light |
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