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

• Mengjie Wang,
• Lanping Dang,
• Wan Xu,
• Zhiying Ma,
• Liuliu Shao,
• Guangxia Wang,
• Chunli Li and
• Hua Wang

Beilstein J. Org. Chem. 2022, 18, 809–817, doi:10.3762/bjoc.18.81

• , fused selenophenes have rarely been reported in the literature because their synthesis is extremely challenging. The first seven-ring-fused heteroacene containing selenophene was synthesized through the intramolecular triple cyclization of bis(o-haloaryl)diacetylene by Yamaguchi in 2005 [22]. Using a

• ; HRMS-DART-FT (m/z): [M]+ calcd for C32H26Se6Si2, 945.6564; found, 945.6564. Molecular structures of bull horn-shaped heteroacene 1, selenophene-based [7]helicene 2 and novel compound DH-3. Five kinds of isomer structures of 5 and two kinds of possible oxidative photocyclization product structures of 6

Synthesis and characterization of S,N-heterotetracenes

• Astrid Vogt,
• Florian Henne,
• Christoph Wetzel,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2020, 16, 2636–2644, doi:10.3762/bjoc.16.214

• reaction; optoelectronic properties; S,N-heteroacene; structure–property relationship; Introduction Thienoacenes and related S,N-heteroacenes have been developed to important π-conjugated systems mainly for application as p-type semiconductor in organic electronic devices with excellent results [1][2][3

• [22][27], organic field-effect transistors [28], or sensors [23]. The interesting structure–property relationships of the S,N-heteroacene series inspired as well theoretical work. In this respect, De Simone et al. computed electronic spectra of the neutral, charged radical cationic, and dicationic

• reacted with o-iodonitrobenzene (17) and Pd[PPh3]4 as catalyst in DMF to give 2,5-bis(2-nitrophenyl)thieno[3,2-b]thiophene (21) in 86% yield. Subsequent Cadogan cyclization with triethyl phosphite under reflux gave hexacyclic S,N-heteroacene 22 in 38% yield which reflects a benzannulated SN4' system with

Synthesis of aryl-substituted thieno[3,2-b]thiophene derivatives and their use for N,S-heterotetracene construction

• Nadezhda S. Demina,
• Nikita A. Kazin,
• Nikolay A. Rasputin,
• Roman A. Irgashev and
• Gennady L. Rusinov

Beilstein J. Org. Chem. 2019, 15, 2678–2683, doi:10.3762/bjoc.15.261

• ketones were used to synthesize new N,S-heterotetracenes, namely 9H-thieno[2',3':4,5]thieno[3,2-b]indoles by their treatment with arylhydrazines in accordance with the Fischer indolization reaction. Keywords: Fiesselmann thiophene synthesis; Fischer indole synthesis; N,S-heteroacene; thieno[3,2-b

• effectively tune their physical characteristics and also reduce production costs since the routine synthesis of heteroacene structures involves cross-coupling reactions catalyzed by expensive transition metals [15]. Thus, in this paper, we would like to present an efficient metal-free synthesis of the aryl

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

• Pierre-Olivier Schwartz,
• Sebastian Förtsch,
• Astrid Vogt,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2019, 15, 1379–1393, doi:10.3762/bjoc.15.138

• ; heteroacene; selenophene; Introduction In recent years, great interest has been devoted to the development of new π-conjugated polycyclic molecules, in particular to polycyclic aromatic hydrocarbons (PAH) such as acenes [1], phenacenes [2], or nanographenes [3]. Corresponding heteroacenes incorporating

• are continuously red-shifted from DTT 1 to DSS 4 the more selenium atoms are present in the heteroacene (292–312 nm). This finding can be explained by the slightly lower aromaticity of the selenophene rings compared to thiophenes as a result from the slightly lower electronegativity (EN 2.55 vs 2.58

• 3.91 eV for DTT 1 to 3.67 eV for DSS 4 due to a stabilization of the HOMO energy level with increasing number of selenium atoms in the heteroacene (vide infra). The extinction coefficients are as well sensitive to the heteroatom in the bridge for pair DTT 1/DTS 2 (26,800 to 22,100 L mol−1 cm−1) and DST

Synthesis and photophysical properties of novel benzophospholo[3,2-b]indole derivatives

• Mio Matsumura,
• Mizuki Yamada,
• Atsuya Muranaka,
• Misae Kanai,
• Naoki Kakusawa,
• Daisuke Hashizume,
• Masanobu Uchiyama and
• Shuji Yasuike

Beilstein J. Org. Chem. 2017, 13, 2304–2309, doi:10.3762/bjoc.13.226

• knowledge, the synthesis of benzophosphole-fused indole derivatives as tetracyclic heteroacenes has not been reported. In 2015, Lu et al. reported the synthesis of only one phosphole and indole-fused pentacyclic heteroacene [35]. Recently, we reported simple and efficient synthetic routes to benzothiophene

• = 75%) was high, comparable to that of phosphole and indole-fused pentacyclic heteroacene (Ф = 70%) [35]. On the other hand, a low fluorescence intensity was observed for phosphine sulfide 5 and selenide 6 (Ф = 1% and 0.3%, respectively). Quenching of fluorescence emission due to a soft sulfur

The effect of milling frequency on a mechanochemical organic reaction monitored by in situ Raman spectroscopy

• Patrick A. Julien,
• Ivani Malvestiti and
• Tomislav Friščić

Beilstein J. Org. Chem. 2017, 13, 2160–2168, doi:10.3762/bjoc.13.216

• organic transformation, the previously reported mechanochemical condensation of a diketone and a diamine to form an N-heteroacene [40]. We have utilized an in-house built setup for real-time Raman spectroscopy monitoring of the synthesis of 2,3-diphenylquinoxaline from benzil and o-phenylenediamine