In:
Green Chemistry, Royal Society of Chemistry (RSC), Vol. 24, No. 18 ( 2022), p. 7113-7121
Abstract:
Despite the recent development of boryl radical reactions, current methods to generate them by relying on photocatalysts or radical initiators cause contamination of the reaction. Herein, a novel system for generating boryl radicals has been developed without using photocatalysts or external radical initiators, and only a catalytic amount of thiol has been used. The success of this approach depends on the dual role of thiol as a proton donor and hydrogen atom transfer (HAT) catalyst. The thiol first reacts with NHC-borane to give boryl sulphides via a dehydrocoupling reaction, and then they undergo in situ cleavage of their B–S bond through photochemical reactions. The radicals obtained were later involved in a fast thiol-catalyzed HAT reaction, affording the hydroboration products. This strategy enables the regioselective hydroboration for scalable synthesis of α- or β-borylated products from many kinds of α,β-unsaturated alkenes and styrenes in good to excellent yields, with broad functional group compatibility at room temperature. The reaction could also be extended to radical-type nucleophilic addition to imines. This unprecedented protocol is anticipated to find potential application in other boryl radical-involved reactions by using boryl sulphides through photochemical reactions.
Type of Medium:
Online Resource
ISSN:
1463-9262
,
1463-9270
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2022
detail.hit.zdb_id:
1485110-6
detail.hit.zdb_id:
2006274-6
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