Redox-Controlled Reactivity at Boron: Parallels to Frustrated Lewis/Radical Pair Chemistry
Redox-Controlled Reactivity at Boron: Parallels to Frustrated Lewis/Radical Pair Chemistry
复制标题
硼的氧化还原控制反应性：与受挫的路易斯/自由基对化学相似
DOI：
10.1021/acs.inorgchem.0c01464
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发表时间：
2020
影响因子：
4.6
通讯作者：
Ménard, Gabriel
中科院分区：
文献类型：
--
作者：
Wong, Anthony;Chu, Jiaxiang;Wu, Guang;Telser, Joshua;Dobrovetsky, Roman;Ménard, Gabriel
本文报道了新的路易斯酸硼烷（Ph_2N）_3 V（μ-N）B（C_6F_5）_2（1a）和（N（CH_2CH_2N（C_6F_5））_3）V（μ-N）B（C_6F_5）_2（1 B）的合成。VIV/Vcouple的氧化还原控制导致可切换的硼烷与“隐藏的”硼自由基反应性，分别模仿受抑刘易斯与受抑自由基对（FLP/FRP）化学。尽管在大体积膦存在下用VV络合物（1 B）观察到异裂FLP型加成反应，但用VIV络合物[CoCp 2 *][（N（CH 2CH 2N（C6 F5））3）V（μ-N）B（C6 F5）2]（3 B）观察到均裂过氧化物或Sn-氢化物键断裂反应，表明硼自由基阴离子特征。通过光谱和计算手段探讨了自由基性质的程度。总之，这些结果表明，VIV/V氧化态的控制允许这些化合物获得在FLP和FRP化学中观察到的反应性。
We report the synthesis of new Lewis-acidic boranes tethered to redox-active vanadium centers, (Ph2N)3V(μ-N)B(C6F5)2(1a) and (N(CH2CH2N(C6F5))3)V(μ-N)B(C6F5)2(1b). Redox control of the VIV/Vcouple resulted in switchable borane versus “hidden” boron radical reactivity, mimicking frustrated Lewis versus frustrated radical pair (FLP/FRP) chemistry, respectively. Whereas heterolytic FLP-type addition reactions were observed with the VVcomplex (1b) in the presence of a bulky phosphine, homolytic peroxide, or Sn–hydride bond cleavage reactions were observed with the VIVcomplex, [CoCp2*][(N(CH2CH2N(C6F5))3)V(μ-N)B(C6F5)2] (3b), indicative of boron radical anion character. The extent of radical character was probed by spectroscopic and computational means. Together, these results demonstrate that control of the VIV/Voxidation states allows these compounds to access reactivity observed in both FLP and FRP chemistry.