Research Abstract


One-shot K-region-selective annulative π-extension for nanographene synthesis and functionalization

2015年2月16日 Nature Communications 6 : 6251 doi: 10.1038/ncomms7251


Kyohei Ozaki, Katsuaki Kawasumi, Mari Shibata, Hideto Ito & Kenichiro Itami

Corresponding Author

伊丹 健一郎
名古屋大学 トランスフォーマティブ生命分子研究所

The optoelectronic nature of two-dimensional sheets of sp2-hydridized carbons (for example, graphenes and nanographenes) can be dramatically altered and tuned by altering the degree of π-extension, shape, width and edge topology. Among various approaches to synthesize nanographenes with atom-by-atom precision, one-shot annulative π-extension (APEX) reactions of polycyclic aromatic hydrocarbons hold significant potential not only to achieve a ‘growth from template’ synthesis of nanographenes, but also to fine-tune the properties of nanographenes. Here we describe one-shot APEX reactions that occur at the K-region (convex armchair edge) of polycyclic aromatic hydrocarbons by the Pd(CH3CN)4(SbF6)2/o-chloranil catalytic system with silicon-bridged aromatics as π-extending agents. Density functional theory calculations suggest that the complete K-region selectivity stems from the olefinic (decreased aromatic) character of the K-region. The protocol is applicable to multiple APEX and sequential APEX reactions, to construct various nanographene structures in a rapid and programmable manner.