Palladium-Catalyzed Annulative π-Extension of Bay-Iodinated Triphenylenes to Access Polycyclic Aromatic Compounds

Abstract

A palladium-catalyzed annulative π-extension reaction of bay-iodinated triphenylenes with aryl iodides/ochloroaromatic carboxylic acids was developed. This approach enabled the synthesis of diverse polycyclic aromatic compounds, including dibenzo[fg,op]tetracenes, azadibenzo[fg,op]tetracenes, and tribenzo[a,g,m]coronenes. Initial studies indicate that the resulting product, 2,3,8,9,14,15-hexakis(decyloxy)tribenzo[a,g,m]coronene, exhibits good liquid-crystalline properties.

Palladium‐Catalyzed Two‐fold Annulation Reaction of 2,6‐Dihalogenobiphenyls with o‐Chloroaromatic Carboxylic Acids to Access (Aza)dibenzo[fg,op]tetracenes

“…Based on the previous reports, [11][12][13][14][15] a possible reaction mechanism for the two-fold annulation reaction is proposed, as depicted in Scheme 2. Initially, the oxidative addition of 2,6-dibromo-4,4'-di-tert-butylbiphenyl 1 a to Pd(0) leads to the formation of Pd(II) complex A, followed by CÀ H activation resulting in the electron-rich palladacycle complex B.…”

“…[14] Our group recently utilized the palladium-catalyzed annulation reaction of bay-iodinated triphenylenes with aryl iodides/o-chloroaromatic carboxylic acids to construct (aza)dibenzo[fg,op]tetracenes (Scheme 1f). [15] Despite the above-mentioned important advances, some effi-cient and facile methods for the synthesis of (aza)dibenzo[fg,op]tetracenes are still expected. Herein, we present a palladium-catalyzed two-fold annulation reaction of 2,6-dihalogenobiphenyl with o-chloroaromatic carboxylic acids [11d,16] to access (aza)dibenzo[fg,op]tetracenes (Scheme 1g).…”