Copper-Catalyzed Regioselective Monodefluoroborylation of Polyfluoroalkenes en Route to Diverse Fluoroalkenes
Copper-Catalyzed Regioselective Monodefluoroborylation of Polyfluoroalkenes en Route to Diverse Fluoroalkenes
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DOI：
10.1021/jacs.7b08343
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发表时间：
2017-09-13
影响因子：
15
通讯作者：
Hosoya, Takamitsu
中科院分区：
文献类型：
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作者：
Sakaguchi, Hironobu;Uetake, Yuta;Hosoya, Takamitsu
多氟烯烃的单脱氟硼化已在温和条件下通过铜催化以区域选择性方式实现。该方法显示出极其广泛的底物范围，包括（二氟乙烯基）芳烃、四氟乙烯（TFE）、（三氟乙烯基对苯二酚和三氟甲基化单氟烯烃）。硼源的选择对于（二氟乙烯基对苯二酚）的有效转化非常重要；（Bpin）（2）适用于具有缺电子芳基的底物，（Bnep）（2）适用于具有富电子芳基的底物。 (氟烯基)-硼酸酯衍生为相应的三氟硼酸钾盐使产物易于分离，这极大地提高了单脱氟硼酸化反应的合成实用性，化学计量实验表明区域选择性的结果取决于β-氟消除的模式，而β-氟消除的模式取决于底物，硼基基团的进一步转化使得氟代烯烃衍生物的制备变得容易。阿托伐他汀的氟代烯烃模拟物，可有效抑制 HMG-CoA 还原酶的酶活性。
Monodefluoroborylation of polyfluoroalkenes has been achieved in a regioselective manner under mild conditions via copper catalysis. The method has shown an extremely broad scope of substrates, including (difluorovinyl)arenes, tetrafluoroethylene (TFE), (trifluorovinyparenes, and trifluoromethylated monofluoroalkenes. The choice of boron source was important for the efficient transformation of (difluorovinyparenes; (Bpin)(2) was suitable for substrates with an electron-deficient aryl group and (Bnep)(2) for those with an electron-rich aryl group. Derivatization of the (fluoroalkenyl)-boronic acid esters to the corresponding potassium trifluoroborate salts has rendered the products easily isolable, which greatly improved the synthetic practicality of the mono defluoroborylation reaction. Stoichiometric experiments indicate that the fate of the regioselectivity depends on the mode of beta-fluorine elimination, which depends on the substrate. Further transformation of the boryl group has allowed facile preparation of fluoroalkene derivatives as exemplified by the synthesis of a fluoroalkene mimic of atorvastatin, which potently inhibited the enzyme activity of HMG-CoA reductase.