Water and Sodium Chloride: Essential Ingredients for Robust and Fast Pd‐Catalysed Cross‐Coupling Reactions between Organolithium Reagents and (Hetero)aryl Halides
作者:Giuseppe Dilauro、Andrea Francesca Quivelli、Paola Vitale、Vito Capriati、Filippo Maria Perna
DOI:10.1002/anie.201812537
日期:2019.2.4
Direct palladium‐catalysed cross‐couplings between organolithium reagents and (hetero)aryl halides (Br, Cl) proceed fast, cleanly and selectively at room temperature in air, with water as the only reaction medium and in the presence of NaCl as a cheap additive. Under optimised reaction conditions, a water‐accelerated catalysis is responsible for furnishing C(sp3)–C(sp2), C(sp2)–C(sp2), and C(sp)–C(sp2)
在室温下,在空气中,以水为唯一反应介质,并在廉价的氯化钠存在下,有机锂试剂与(杂)芳基卤化物(Br,Cl)之间的直接钯催化交叉偶联快速,清洁且选择性地进行。在优化的反应条件下,水加速催化作用可提供C(sp 3)–C(sp 2),C(sp 2)–C(sp 2)和C(sp)–C(sp 2))交叉偶联的产品,在20 s的反应时间内与质子分解竞争,产率高达99%,并且即使在挑战性的二级有机锂用作原料的情况下,也没有不希望的脱卤/均偶联副产物存在。值得注意的是,该协议具有可扩展性,并且催化剂和水可以轻松,成功地回收多达10次,而E因子低至7.35。