Visible Light Activation of Boronic Esters Enables Efficient Photoredox C(sp2)–C(sp3) Cross‐Couplings in Flow. (6th October 2016)

• Record Type: Journal Article
• Authors: Lima, Fabio; Kabeshov, Mikhail A.; Tran, Duc N.; Battilocchio, Claudio; Sedelmeier, Joerg; Sedelmeier, Gottfried; Schenkel, Berthold; Ley, Steven V.
• Is Part Of: Angewandte Chemie. Volume 128:Number 45(2016)
• Page Start: 14291
• Page End: 14295
• Publication Date: 2016-10-06
• Subjects: Borsäureester -- Durchflusschemie -- Kreuzkupplungen -- Photoredoxkatalyse -- Synthesemethoden; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201605548
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: We report herein a new method for the photoredox activation of boronic esters. Using these reagents, an efficient and high‐throughput continuous flow process was developed to perform a dual iridium‐ and nickel‐catalyzed C(sp 2 )–C(sp 3 ) coupling by circumventing solubility issues associated with potassium trifluoroborate salts. Formation of an adduct with a pyridine‐derived Lewis base was found to be essential for the photoredox activation of the boronic esters. Based on these results we were able to develop a further simplified visible light mediated C(sp 2 )–C(sp 3 ) coupling method using boronic esters and cyano heteroarenes under flow conditions.