A Direct One‐Pot Synthesis of Asymmetric Dehydrobenzopyrido[12]annulenes and Their Physicochemical Properties

Abstract

A direct one‐pot synthesis of asymmetric dehydrobenzopyrido[12]annulenes 2 and 3 containing one or two pyridine rings is reported that employs a Stephens–Castro mediated cross‐coupling of mixtures of ethynylcuprate precursors. The spectroscopic and theoretical properties of 2 and 3 are compared to those of the threefold symmetric dehydrotribenzo[12]annulene 1, and dehydrotripyrido[12]annulenes 4 and 5 and dehydrodibenzodipyrido[16]annulene byproduct 6, and showed 1–5 to be essentially isoelectronic band gap materials whose electron accepting ability increases with increasing nitrogen incorporation. The structures of 2, 4 and 6 were also unambiguously characterized by X‐ray crystallography. The results highlight the potential dehydroaryl[12]annulenes incorporating pyridines offer for the construction of high carbon content electronic materials.

Ir-Catalyzed Cycloaddition of Tribenzocyclyne with Biphenylenes

“…All chemicals were purchased from common commercial sources: Sigma-Aldrich, Fluorochem, Alfa Aesar, Acros Organics, and PENTA. Compounds 1 , 7 , and 8 were prepared according to known methods. Toluene and tetrahydrofuran for reactions were distilled from solvent–sodium benzophenone systems.…”

“…Although 1 is comparatively easy to synthesize, it has been used in only a few reactions. These encompass reductive cyclization with lithium to a dilithium dianion (Youngs et al) and the on-surface reductive cyclization to benzo­[ a ]­indeno­[2,1- c ]­fluorene and other species (Kawai et al) .…”