研究室工作进展 Aug. 10th, 2019

Reversible Two-Electron Redox Reactions Involving Tetralithio/Dilithio

Palladole, Platinacycle, and Dicupra[10]annulene

Zhe Huang, Yongliang Zhang, Wen-Xiong Zhang,*and Zhenfeng Xi*

Organometallics 2019, 38, 2807-2811.

The reaction chemistry of metalla-aromatics is fundamentally interesting. In this work, it is found that tetralithio spiroaromatic palladole and platinacycle complexes undergo selective two-electron oxidation reaction with 1,2-dibromoethane as a mild oxidant, affording their corresponding dilithio spiro metallacyclopentadienes. These dilithio spiro complexes can be reductively transformed to their corresponding tetralithio spiroaromatic complexes with metallic lithium. When treated with an appropriate amount of oxidants, both can generate 1,4-dihydropentalene derivatives via a mechanism involving reductive elimination and silyl migration, as supported by DFT calculation. Similarly, tetralithio aromatic dicupra[10]annulene can also undergo the above reversible two-electron redox reaction. These results enriched the knowledge of reactivity of metalla-aromatic compounds.