Chen Liye, Francis Haydn, Carrow Brad P
Department of Chemistry, Princeton University, Princeton, NJ 08544.
ACS Catal. 2018 Apr 6;8(4):2989-2994. doi: 10.1021/acscatal.8b00341. Epub 2018 Mar 2.
The use of fluorinated arylboronic acid building blocks in cross-coupling has remained challenging due to their acute base sensitivity. We report a general solution to this problem using a true catalytic intermediate, Pd(PAd)(-FCH)Br, as a uniquely effective "on-cycle" precatalyst that allows Suzuki-Miyaura coupling to occur much faster than even the most severe protodeboronation side reactions. Control of boron speciation between the active acid and dormant ester forms was also found to play a critical role in balancing the rates of catalysis versus reagent decomposition. This method is compatible with any fluorination pattern, base-labile functional groups, and a range of bromo(hetero)arenes.
由于氟代芳基硼酸结构单元对碱极为敏感，其在交叉偶联反应中的应用一直具有挑战性。我们报道了一种通用的解决方案，使用真正的催化中间体Pd(PAd)(-FCH)Br作为一种独特有效的“循环中”预催化剂，使得铃木-宫浦偶联反应的发生速度比最严重的原脱硼副反应还要快得多。还发现控制活性酸形式和休眠酯形式之间的硼形态在平衡催化速率与试剂分解速率方面起着关键作用。该方法与任何氟化模式、对碱不稳定的官能团以及一系列溴代（杂）芳烃兼容。
