Institute of Organic Chemistry, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany.
ChemSusChem. 2022 Aug 5;15(15):e202200906. doi: 10.1002/cssc.202200906. Epub 2022 Jun 13.
α-Amino radicals from simple tertiary amines were employed as halogen atom transfer (XAT) agents in metallaphotoredox catalysis for cross-electrophile couplings of organic bromides with organic iodides. This XAT strategy proved to be efficient for the generation of carbon radicals from a range of partners (alkyl, aryl, alkenyl, and alkynyl iodides). The reactivities of these radical intermediates were captured by nickel catalysis with organobromides including aryl, heteroaryl, alkenyl, and alkyl bromides, enabling six diverse C-C bond formations. Classic named reactions including Negishi, Suzuki, Heck, and Sonogashira reactions were readily achieved in a net-reductive fashion under mild conditions. More importantly, the cross coupling was viable with either organic bromide or iodide as limiting reactant based on the availability of substrates, which is beneficial to the late-stage functionalization of complex molecules. The scalability of this method in batch and flow was investigated, further demonstrating its applicability.
简单的叔胺中的α-氨基自由基被用作金属光氧化还原催化中卤原子转移 (XAT) 试剂，用于有机溴化物与有机碘化物的交叉电亲核偶联。这种 XAT 策略被证明可以有效地从各种亲核试剂（烷基、芳基、烯基和炔基碘化物）中生成碳自由基。这些自由基中间体的反应性通过镍催化与有机溴化物（包括芳基、杂芳基、烯基和烷基溴化物）捕获，实现了六种不同的 C-C 键形成。在温和条件下，通过净还原方式可以轻松实现 Negishi、Suzuki、Heck 和 Sonogashira 等经典命名反应。更重要的是，根据底物的可用性，交叉偶联可以使用有机溴化物或碘化物作为限制反应物，这有利于复杂分子的后期功能化。该方法在批量和流动中的可扩展性进行了研究，进一步证明了其适用性。
