Gordeev Evgeniy G, Pentsak Evgeniy O, Ananikov Valentine P
Zelinsky Institute of Organic Chemistry , Russian Academy of Sciences , Leninsky prospekt 47 , Moscow 119991 , Russia.
J Am Chem Soc. 2020 Feb 26;142(8):3784-3796. doi: 10.1021/jacs.9b10887. Epub 2020 Feb 14.
Development of sustainable catalysts for synthetic transformations is one of the most challenging and demanding goals. The high prices of precious metals and the unavoidable leaching of toxic metal species leading to environmental contamination make the transition metal-free catalytic systems especially important. Here we demonstrate that carbene active centers localized on carbon atoms at the zigzag edge of graphene represent an alternative platform for efficient catalytic carbon-carbon bond formation in the synthesis of benzene. The studied acetylene trimerization reaction is an efficient atom-economic route to build an aromatic ring-a step ubiquitously important in organic synthesis and industrial applications. Computational modeling of the reaction mechanism reveals a principal role of the reversible spin density oscillations that govern the overall catalytic cycle, facilitate the product formation, and regenerate the catalytically active centers. Dynamic π-electron interactions in 2D carbon systems open new opportunities in the field of carbocatalysis, unachievable by means of transition metal-catalyzed transformations. The theoretical findings are confirmed experimentally by generating key moieties of the carbon catalyst and performing the acetylene conversion to benzene.
开发用于合成转化的可持续催化剂是最具挑战性和高要求的目标之一。贵金属的高价格以及有毒金属物种不可避免的浸出导致环境污染，使得无过渡金属催化体系尤为重要。在此，我们证明位于石墨烯锯齿边缘碳原子上的卡宾活性中心是苯合成中高效催化碳 - 碳键形成的另一种平台。所研究的乙炔三聚反应是构建芳环的高效原子经济途径——这一步骤在有机合成和工业应用中普遍重要。反应机理的计算模型揭示了可逆自旋密度振荡的主要作用，其控制整个催化循环，促进产物形成，并再生催化活性中心。二维碳体系中的动态π电子相互作用为碳催化领域带来了新机遇，这是过渡金属催化转化无法实现的。通过生成碳催化剂的关键部分并将乙炔转化为苯，实验证实了理论发现。
