Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Rare-earth Materials Chemistry and Applications & Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
J Am Chem Soc. 2023 Mar 29;145(12):6633-6638. doi: 10.1021/jacs.3c01466. Epub 2023 Mar 14.
Selective cleavage of C-C bonds within arene rings is of great interest but remains elusive, especially for the molecules possessing the active and inert C-C bonds. Here, we report that the active and inert C-C bonds of biphenylene could be controllably cleaved by the reaction of biphenylene, potassium graphite, and rare-earth complexes with different metal centers. For scandium, the bond activation occurs at the C-C single bond, yielding 9-scandafluorene. For Lu, the reaction goes through ring contraction of the aromatic ring in biphenylene to provide benzopentalene dianionic lutetium. The origin of the selectivity and the reaction mechanism were illustrated by the isolation of intermediates and DFT calculations.
芳环中环 C-C 键的选择性断裂具有重要意义，但仍然难以实现，特别是对于那些具有活性和惰性 C-C 键的分子。在这里，我们报告说，双苯乙烯、钾石墨和具有不同金属中心的稀土配合物的反应可以控制双苯乙烯中活性和惰性 C-C 键的断裂。对于钪，键的活化发生在 C-C 单键上，生成 9-钪芴。对于镥，反应通过双苯乙烯中环的收缩进行，提供苯并戊二烯二负离子镥。通过中间体的分离和 DFT 计算，说明了选择性的起源和反应机制。
