Li Chaokun, Liao Shangteng, Chen Shanglin, Chen Nan, Zhang Feng, Yang Kai, Song Qiuling
Key Laboratory of Molecule Synthesis and Function Discovery, Fujian Province University, College of Chemistry and College of Materials Science at Fuzhou University, Fuzhou, Fujian, 350108, China.
Institute of Next Generation Matter Transformation, College of Material Sciences Engineering, Huaqiao University, Xiamen, Fujian, 361021, China.
Nat Commun. 2022 Apr 4;13(1):1784. doi: 10.1038/s41467-022-29466-3.
Tetracoordinate boron species have emerged as radical precursors via deboronation by photo-induced single electron transfer (SET) pathway. These reactions usually produce an alkyl radical and boron-bound species, and the valuable boron species are always discarded as a by-product. Given the importance of boron species, it will be very attractive if the two parts could be incorporated into the eventual products. Herein we report a photo-catalyzed strategy in which in situ generated tetracoordinated boron species decomposed into both alkyl radicals and boron species under visible light irradiation, due to the pre-installation of a vinyl group on the aromatic ring, the newly generated alkyl radical attacks the vinyl group while leaving the boron species on ipso-position, then both radical part and boron moiety are safely incorporated into the final product. Tertiary borons, secondary borons, gem-diborons as well as 1,2-diborons, and versatile electrophiles are all well tolerated under this transformation, of note, ortho-, meta- and para-bromostyrenes all demonstrated good capabilities. The reaction portraits high atom economy, broad substrate scope, and diversified valuable products with tertiary or quaternary carbon center generated, with diborons as substrates, Csp-B and Csp-B are established simultaneously, which are precious synthetic building blocks in chemical synthesis.
通过光诱导单电子转移（SET）途径的脱硼反应，四配位硼物种已成为自由基前体。这些反应通常会产生一个烷基自由基和硼结合物种，而有价值的硼物种总是作为副产物被丢弃。鉴于硼物种的重要性，如果这两部分都能被纳入最终产物中，将非常有吸引力。在此，我们报道了一种光催化策略，其中原位生成的四配位硼物种在可见光照射下分解为烷基自由基和硼物种，由于在芳环上预先安装了乙烯基，新生成的烷基自由基攻击乙烯基，同时将硼物种留在本位，然后自由基部分和硼部分都安全地纳入最终产物中。叔硼、仲硼、偕二硼以及1,2 -二硼，以及多种亲电试剂在这种转化中都能很好地耐受，值得注意的是，邻、间、对溴苯乙烯都表现出良好的反应能力。该反应具有高原子经济性、广泛的底物范围以及生成带有叔碳或季碳中心的多种有价值产物的特点，以二硼为底物时，同时构建了Csp - B和Csp - B键，它们是化学合成中珍贵的合成砌块。
