Selenophene-containing heterotriacenes by a C–Se coupling/cyclization reaction

Abstract

A new novel family of tricyclic sulfur and/or selenium-containing heterotriacenes 2–4 with an increasing number of selenium (Se) atoms is presented. The heterotriacene derivatives were synthesized in multistep synthetic routes and the crucial cyclization steps to the stable and soluble fused systems were achieved by copper-catalyzed C–S and C–Se coupling/cyclization reactions. Structures and packing motifs in the solid state were elucidated by single crystal X-ray analysis and XRD powder measurements. Comparison of the optoelectronic properties provides interesting structure–property relationships and gives valuable insights into the role of heteroatoms within the series of the heterotriacenes. Electrooxidative polymerization led to the corresponding poly(heterotriacene)s P2–P4.

Dithieno[3,2-b:2′,3′-d]thiophene (DTT): an emerging heterocyclic building block for future organic electronic materials & functional supramolecular chemistry

“…Amongst, a variety of heteroatoms selenium (Se) has only scarcely been employed into the aromatic rings, may be due expensiveness of selenophene itself, and also because of an inadequate number of commercial availability of its derivatives, hence its chemistry is less explored and needed to be exploited to the advanced level. To this context, selenophene-containing heterotriacenes through the C-Se coupling and/or copper-catalyzed cyclization as key steps in multistep synthetic approach has fruitfully been reported by the Schwartz et al (Scheme 22) 120 In this paper, the authors have not only prepared the DTT system 2 by an alternative route but also assembled its Se-substituted tricyclic congeners 155-157. The single X-ray crystal structure and XRD powder analysis were employed for their chemical structures determination & packing motifs establishment.…”

Pd-Free synthesis of dithienothiophene-based oligoaryls for effective hole-transporting materials by optimized Cu-catalyzed annulation and direct C–H arylation

“…Compared to the palladium-catalysis, we anticipated that a copper-based catalytic system would be relatively milder, which might restrict the competitive C-H bond activations/functionalizations. Therefore, we demonstrate herein a copper-catalyzed ring-closure of 3 using inexpensive thioacetate instead of high-cost K 2 S, 10 which afforded the versatile dithieno [3,2-b:2′,3′-d]thiophene in excellent isolated yields of up to 92% (Scheme 1, approach C). In addition to developing copper-catalyzed C-S bond formation/annulation, the bidirectional π-extension from the DTT core has also been achieved by copper-catalysed direct C-H/C-I cross-couplings under preoptimized conditions, successfully producing three new oligoaryls that were applied as effective hole-transporting materials (HTMs) in perovskite solar cells (PSCs).…”

Thiophene/selenophene-based S-shaped double helicenes: regioselective synthesis and structures

“…In 2017, we reported the first member of diselenoselenophenes ( DSS s), 2,5-di(trimethylsilanyl)diseleno[2,3- b :3′,2′- d ]selenophene ((TMS) 2 - bb - DSS ), from which the TMS group could easily be removed by trifluoroacetic acid and replaced by bromine [ 27 ]. Another isomer of DSS , diseleno[3,2- b :2′,3′- d ]selenophene ( tt - DSS ) has been successively synthesized from selenophene [ 28 – 29 ].…”