An "On-Cycle" Precatalyst Enables Room-Temperature Polyfluoroarylation Using Sensitive Boronic Acids
An "On-Cycle" Precatalyst Enables Room-Temperature Polyfluoroarylation Using Sensitive Boronic Acids
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DOI：
10.1021/acscatal.8b00341
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发表时间：
2018-04-01
期刊：
影响因子：
12.9
通讯作者：
Carrow, Brad P.
中科院分区：
文献类型：
--
作者：
Chen, Liye;Francis, Haydn;Carrow, Brad P.
由于氟化芳基硼酸结构单元具有强烈的碱敏感性，在交叉偶联中的使用仍然具有挑战性。我们报告了该问题的通用解决方案，使用真正的催化中间体 Pd(PAd(3))(p-FC6H4)Br 作为一种独特有效的“循环”预催化剂，使 Suzuki Miyaura 偶联的发生速度比最严重的原脱硼副反应快得多。还发现，控制活性酸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发挥着关键作用。该方法与任何氟化模式、碱不稳定官能团和一系列溴（杂）芳烃兼容。
The use of fluorinated arylboronic acid building blocks in cross-coupling has remained challenging, because of their acute base sensitivity. We report a general solution to this problem using a true catalytic intermediate, Pd(PAd(3))(p-FC6H4)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.