Yin Jiangliang, Zhou Fulin, Zhu Lei, Yang Mufan, Lan Yu, You Jingsong
Key Laboratory of Green Chemistry and Technology of Ministry of Education , College of Chemistry , Sichuan University , 29 Wangjiang Road , Chengdu 610064 , PR China . Email:
School of Chemistry and Chemical Engineering , Chongqing University , Chongqing 400030 , PR China.
Chem Sci. 2018 May 29;9(24):5488-5493. doi: 10.1039/c8sc01963k. eCollection 2018 Jun 28.
Herein, we propose the conception of heteroatom-promoted delocalization of the positive charge of an oxonium ion and thus develop a highly efficient rhodium(iii)-catalyzed hydration and three fold C-H activation/annulation cascade of arylnitriles with alkynes, affording a structurally diverse family of delocalized polycyclic aromatic hydrocarbon (PAH) carbocations. DFT calculations demonstrate that the positive charge mostly locates around the C1 atom and is partly delocalized by ambient N, O1 and C5 atoms. A mechanistic study indicates that the hydration of the arylnitrile and three fold insertion of the alkyne is a successive process rather than a step by step process, wherein a unique intramolecular rhodium migration is probably involved. These novel carbeniums show tunable fluorescence emission, low cytotoxicity and the ability to specifically target lysosomes.
在此，我们提出了杂原子促进氧鎓离子正电荷离域的概念，从而开发了一种高效的铑(III)催化的芳腈与炔烃的水合反应以及三重C-H活化/环化级联反应，得到了结构多样的离域多环芳烃(PAH)碳正离子家族。密度泛函理论计算表明，正电荷主要位于C1原子周围，并部分被周围的N、O1和C5原子离域。机理研究表明，芳腈的水合反应和炔烃的三重插入是一个连续的过程，而不是分步过程，其中可能涉及独特的分子内铑迁移。这些新型碳正离子具有可调谐的荧光发射、低细胞毒性以及特异性靶向溶酶体的能力。
