Visible Light Activation of Boronic Esters Enables Efficient Photoredox C(sp2)–C(sp3) Cross‐Couplings in Flow期刊界 All Journals 搜尽天下杂志传播学术成果专业期刊搜索期刊信息化学术搜索

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

Authors:	Fabio Lima Dr Mikhail A Kabeshov Dr Duc N Tran Dr Claudio Battilocchio Dr Joerg Sedelmeier Dr Gottfried Sedelmeier Dr Berthold Schenkel Prof Steven V Ley

Affiliation:	1. http://www.leygroup.ch.cam.ac.uk 0000-0003-2127-9568 Department of Chemistry, University of Cambridge, Cambridge, UK;2. Department of Chemistry, University of Cambridge, Cambridge, UK;3. Novartis Pharma AG, Basel, Switzerland

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(sp²)–C(sp³) 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(sp²)–C(sp³) coupling method using boronic esters and cyano heteroarenes under flow conditions.

Keywords:	boronic esters cross-coupling flow chemistry photoredox catalysis synthetic methods