Synthesis of 1,2,3,4,8,9,10,11‐Octasubstituted Pentacenequinone Derivatives and their Conversion into Substituted Pentacenes

Abstract

A series of 1,2,3,4,8,9,10,11-octasubstituted pentacenequinone derivatives were prepared by the oxidation of 1,2,3,4,8,9,10,11-octasubstituted pentacenes, which were synthesized by the double homologation method. Oxidation of the pentacenes was carried out with H(5)IO(6) or air and DDQ. These octasubstituted pentacenequinones were converted into 1,2,3,4,6,8,9,10,11,13-decasubstituted or 2,3,6,9,10,13-hexasubstituted pentacene derivatives by the introduction of aryl or alkynyl groups at the carbonyl carbons. The photophysical properties of these new pentacenes have been measured in solution, and the substituent effects are discussed.

Spacer‐Extended Bis‐Ene‐Yne Compounds: Scope, Limitations, and Properties

“…In the first step 6a was lithiated via metal–halogen exchange and 9,10‐anthracenedione was added to form an isomeric mixture of diol 23 (56 %) . Diol 23 was further converted into the target compound 24 by reductive aromatization utilizing SnCl 2 in 65 % yield …”

“…2,2′‐(9,10‐Anthracenediyl)bis[4‐bromo‐5‐(trimethylsilyl)thiophene] (24): The preparation of 24 was performed as a modification of a published procedure . 23 (0.81 g, 1.20 mmol, 1.00 equiv.)…”

Dibromoisobenzofuran as a Formal Equivalent of Didehydroisobenzofuran: Reactive Platform for Expeditious Assembly of Polycycles

“…Subsequent acid catalyzed aromatization cleanly occurred by treatment of 16 with H 2 SO 4 in toluene at 25 °C. Purification of the crude products by silica gel column chromatography gave substituted pentacene 17 in 71% yield as blue solids. − The structure of 17 was determined by X-ray analysis…”