(o‐Phenylenediamino)borylstannanes: Efficient Reagents for Borylation of Various Alkyl Radical Precursors
(o‐Phenylenediamino)borylstannanes: Efficient Reagents for Borylation of Various Alkyl Radical Precursors
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(邻苯二氨基)硼基锡烷：各种烷基自由基前体硼化的有效试剂
DOI：
10.1002/chem.202004692
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发表时间：
2020
影响因子：
4.3
通讯作者：
Yasuda Makoto
中科院分区：
文献类型：
--
作者：
Suzuki Kensuke;Nishimoto Yoshihiro;Yasuda Makoto
合成了（o -苯基二氨基）硼基锡烷，以实现多种烷基自由基前体的硼基取代。在自由基引发剂的存在下进行脱卤、脱氨、脱碳和脱羧硼化反应，得到相应的有机硼化合物。自由基时钟实验和计算研究为硼基锡烷与烷基自由基中间体的均溶取代（SH2）机理提供了新的见解。DFT计算表明，苯二胺结构降低了包括硼原子上的空p轨道在内的LUMO能级，从而增强了对SH2中烷基自由基的反应活性。此外，THF的C（sp3）‐H硼化是利用山酮的三重态完成的。
(o‐Phenylenediamino)borylstannanes were newly synthesized to achieve radical boryl substitutions of a variety of alkyl radical precursors. Dehalogenative, deaminative, decharcogenative, and decarboxylative borylations proceeded in the presence of a radical initiator to give the corresponding organic boron compounds. Radical clock experiments and computational studies have provided insights into the mechanism of the homolytic substitution (SH2) of the borylstannanes with alkyl radical intermediates. DFT calculation disclosed that the phenylenediamino structure lowered the LUMO level including the vacant p‐orbital on the boron atom to enhance the reactivity to alkyl radicals in SH2. Moreover, C(sp3)‐H borylation of THF was accomplished using the triplet state of xanthone.