Bismuth-Mediated a-Arylation of Acidic Diketones with ortho -Substituted Boronic Acids
Bismuth-Mediated a-Arylation of Acidic Diketones with ortho -Substituted Boronic Acids
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铋介导的酸性二酮与邻位取代硼酸的 a-芳基化
DOI：
10.1002/ange.202210840
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发表时间：
2022
影响因子：
--
通讯作者：
Ruffell K
中科院分区：
文献类型：
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作者：
Ruffell K
环状和氟烷基1，3-二酮的α-芳基化由于相应烯醇化物的高度稳定性而具有挑战性，并且对于空间要求高的芳基配偶体尤其困难。作为这个问题的一般解决方案，我们报道了Bi介导的酸性二酮和邻位取代芳基硼酸的氧化偶联。从实验室稳定的双金属前体开始，一系列的B-至-Bi的金属转移、氧化和C-C键形成使芳基化的二酮脱附。开发的方法，容忍敏感的功能和空间需求的关键活性中间体的询问支持。应用我们的策略，环二酮，使简洁的合成重要的农业化学中间体，以前使用有毒的铅试剂制备。该方法还使得氟烷基二酮的首次芳基化成为可能，其在与肼缩合时提供直接获得有价值的氟烷基吡唑的途径。
The α‐arylation of cyclic and fluoroalkyl 1,3‐diketones is made challenging by the highly stabilized nature of the corresponding enolates, and is especially difficult for sterically demanding aryl partners. As a general solution to this problem, we report the Bi‐mediated oxidative coupling of acidic diones andortho‐substituted arylboronic acids. Starting from a bench‐stable bismacycle precursor, a sequence of B‐to‐Bi transmetallation, oxidation and C−C bond formation furnishes the arylated diones. Development of methodology that tolerates both sensitive functionality and steric demand is supported by interrogation of key reactive intermediates. Application of our strategy to cyclic diones enables the concise synthesis of important agrochemical intermediates which were previously prepared using toxic Pb reagents. This methodology also enables the first ever arylation of fluoroalkyl diones which, upon condensation with hydrazine, provides direct access to valuable fluoroalkyl pyrazoles.