Mu Xin, Axtell Jonathan C, Bernier Nicholas A, Kirlikovali Kent O, Jung Dahee, Umanzor Alexander, Qian Kevin, Chen Xiangyang, Bay Katherine L, Kirollos Monica, Rheingold Arnold L, Houk K N, Spokoyny Alexander M
Department of Chemistry and Biochemistry, University of California, Los Angeles, 609 Charles E. Young Drive East, Los Angeles, CA 90095, USA.
Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California, 92093, USA.
Chem. 2019 Sep 12;5(9):2461-2469. doi: 10.1016/j.chempr.2019.07.018. Epub 2019 Aug 22.
A cornerstone of modern synthetic chemistry rests on the ability to manipulate the reactivity of a carbon center by rendering it either electrophilic or nucleophilic. However, accessing a similar reactivity spectrum with boron-based reagents has been significantly more challenging. While classical nucleophilic carbon-based reagents normally do not require steric protection, readily accessible, unprotected boron-based nucleophiles have not yet been realized. Herein, we demonstrate that the bench stable -hexaborate cluster anion can engage in a nucleophilic substitution reaction with a wide array of organic and main group electrophiles. The resulting molecules containing B‒C bonds can be further converted to tricoordinate boron species widely used in organic synthesis.
现代有机合成化学的一个基石在于通过使碳中心具有亲电性或亲核性来控制其反应活性的能力。然而，使用硼基试剂获得类似的反应活性范围则要困难得多。虽然经典的基于碳的亲核试剂通常不需要空间保护，但易于获得的、未受保护的硼基亲核试剂尚未实现。在此，我们证明了在实验台上稳定的六硼酸盐簇阴离子可以与多种有机和主族亲电试剂发生亲核取代反应。由此产生的含B-C键的分子可以进一步转化为有机合成中广泛使用的三配位硼物种。
