Effect of substitution position of aryl groups on the thermal back reactivity of aza-diarylethene photoswitches and prediction by density functional theory

• Misato Suganuma,
• Daichi Kitagawa,
• Shota Hamatani and
• Seiya Kobatake

Beilstein J. Org. Chem. 2025, 21, 242–252, doi:10.3762/bjoc.21.16

• benzothiophene (N3 and I3) or benzofuran (N4 and I4), the ΔH‡ values were almost the same, but the ΔS‡ values became larger and took positive values by the change of the substitution position of the aryl group from N to I. Furthermore, comparing the ΔG‡(exp) and the t1/2 values, when the aryl group is

• phenylthiophene (N1 and I1) or benzothiophene (N3 and I3), the ΔG‡(exp) value decreased and the t1/2 became shorter by the change of the substitution position of the aryl group from N to I. On the other hand, when the aryl group is phenylthiazole (N2 and I2) or benzofuran (N4 and I4), the ΔG‡(exp) and the t1/2

Recent advances in organocatalytic atroposelective reactions

• Henrich Szabados and
• Radovan Šebesta

Beilstein J. Org. Chem. 2025, 21, 55–121, doi:10.3762/bjoc.21.6

• -workers developed atroposelective formation of benzothiophene-fused biaryls via formal (4 + 2) annulation [35]. The NHC catalyst C12 was the most efficient for realizing the de novo formation of a new aryl ring within the newly formed axially chiral biaryl 51 from enals 49 and 2-benzylbenzothiophene- or

C–C Coupling in sterically demanding porphyrin environments

• Liam Cribbin,
• Brendan Twamley,
• Nicolae Buga,
• John E. O’ Brien,
• Raphael Bühler,
• Roland A. Fischer and
• Mathias O. Senge

Beilstein J. Org. Chem. 2024, 20, 2784–2798, doi:10.3762/bjoc.20.234

• -dinitrophenylboronic acid has a marginally lower pKa than pentafluorophenyl boronic acid [46]; however, it undergoes protodeboronation, several orders of magnitude slower [47]. The synthesis of porphyrin 31 with a benzothiophene moiety, proved challenging (Table 1, entries 14–19). Use of a microwave-assisted procedure

Copper-catalyzed yne-allylic substitutions: concept and recent developments

• Shuang Yang and
• Xinqiang Fang

Beilstein J. Org. Chem. 2024, 20, 2739–2775, doi:10.3762/bjoc.20.232

• substituted pybox ligand (Scheme 28, 26a–m). The thiophene unit of the carbonate could also be replaced by benzothiophene (Scheme 28, 26h) or furan (Scheme 28, 26m), and pyrrole (Scheme 28, 26j), phenol (Scheme 28, 26k); coumarin derivative (Scheme 28, 26n), and dibenzylamine (Scheme 28, 24a) could also

Synthesis of benzo[f]quinazoline-1,3(2H,4H)-diones

• Ruben Manuel Figueira de Abreu,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2708–2719, doi:10.3762/bjoc.20.228

• respective cyclisation product. Hence, the application of the reaction conditions to starting materials 4b, 4c and 4e resulted in the decomposition of the starting materials and no product could be isolated. The employment of heterocyclic benzothiophene gave a very good yield of 80% for product 5i. Optical

Asymmetric organocatalytic synthesis of chiral homoallylic amines

• Nikolay S. Kondratyev and
• Andrei V. Malkov

Beilstein J. Org. Chem. 2024, 20, 2349–2377, doi:10.3762/bjoc.20.201

• -trifluoromethylamine derivatives of high molecular complexity (Scheme 28). The process involves a highly enantioselective reaction of the isatin-derived Morita–Baylis–Hillman carbonate 137 with a novel α-CF3-substituted imine 136, derived from inexpensive benzothiophene-2,3-dione. A C2-symmetrical cinchona-derived

• %), good to excellent yields (65–98%), and consistently high diasterioselectivities (>20:1). For selected examples, the reaction was successfully performed on a 1 gram scale. Apart from benzothiophene-2-one imine, the reaction also worked well with diethyl oxomalonate-derived trifluoromethylimine. A

• products 131 [43]. Chiral organocatalysed addition of 2,2,2-trifluoroethyl ketimines to isatin-derived Morita–Baylis–Hilman carbonates [44]. Chiral chinchona-derived amine-catalysed reaction between isatin-based Morita–Baylis–Hilman carbonate and benzothiophene-2-one α-trifluoromethylimine [44]. (R)-VAPOL

Bismuth(III) triflate: an economical and environmentally friendly catalyst for the Nazarov reaction

• Manoel T. Rodrigues Jr.,
• Aline S. B. de Oliveira,
• Ralph C. Gomes,
• Amanda Soares Hirata,
• Lucas A. Zeoly,
• Hugo Santos,
• João Arantes,
• Catarina Sofia Mateus Reis-Silva,
• João Agostinho Machado-Neto,
• Leticia Veras Costa-Lotufo and
• Fernando Coelho

Beilstein J. Org. Chem. 2024, 20, 1167–1178, doi:10.3762/bjoc.20.99

• desired products were obtained in good to excellent yields and E-selectivities (Figure 2) [71][72][73][74]. Various substrates (9aa–gc), containing electron-donating, electron-withdrawing, electroneutral groups, and heteroaryl units (2-thiophene and 3-benzothiophene) were obtained in good to excellent

Quinoxaline derivatives as attractive electron-transporting materials

• Zeeshan Abid,
• Liaqat Ali,
• Sughra Gulzar,
• Faiza Wahad,
• Raja Shahid Ashraf and
• Christian B. Nielsen

Beilstein J. Org. Chem. 2023, 19, 1694–1712, doi:10.3762/bjoc.19.124

• the earlier [54]. Recently, Ding et al. prepared a novel air-stable n-type benzothiophene endcapped azaarene (BTPQ) and its sulfonated derivative (BSPQ). By introducing nitrogen atoms and sulfonyl groups, the researchers modulated the molecular energy levels and achieved the energy level requirements

Synthesis of medium and large phostams, phostones, and phostines

• Jiaxi Xu

Beilstein J. Org. Chem. 2023, 19, 687–699, doi:10.3762/bjoc.19.50

• ]thiophen-3-yl)methanol (23) and benzyl allylphosphonochlordiate (24) in the presence of triethylamine in diethyl ether via phosphonylation. It underwent a RCM reaction under the catalysis of Grubbs first generation catalyst in DCM, affording 2-(4-methylphenyl)benzothiophene-fused 2-(benzyloxy)-3,6,7,8,9,10

• -hexahydro-1,2-oxaphosphecine 2-oxide 26 in 70% yield. After the Pd-catalyzed hydrogenolysis, it was transformed to both cyclic ten-membered phostone 2-(4-methylphenyl)benzothiophene-fused 2-hydroxy-1,2-oxaphosphecane 2-oxide (27) in 40% yield and acyclic (4-(3-methyl-2-(4-methylphenyl)benzo[b]thiophen-4-yl

• . The RCM reaction was performed in the presence of Grubbs first generation catalyst in DCM, affording 2-(4-methylphenyl)benzothiophene-fused 2-(benzyloxy)-3,4,5,6,7,10-hexahydro-1,2-oxaphosphecine 2-oxide 31 in 70% yield. After hydrazine reduction and Pd-catalyzed hydrogenolysis, it was converted into

Transition-metal-catalyzed domino reactions of strained bicyclic alkenes

• Austin Pounder,
• Eric Neufeld,
• Peter Myler and
• William Tam

Beilstein J. Org. Chem. 2023, 19, 487–540, doi:10.3762/bjoc.19.38

• previously been a challenging transformation due to the propensity of these systems to produce non-cyclized hydroarylation products due to an unproductive rhodium 1,4-migration on heteroaromatic moieties. The use of benzothiophene, benzofurans, and benzopyrrole boronate esters in this investigation prevented

Transition-metal-catalyzed C–H bond activation as a sustainable strategy for the synthesis of fluorinated molecules: an overview

• Louis Monsigny,
• Floriane Doche and
• Tatiana Besset

Beilstein J. Org. Chem. 2023, 19, 448–473, doi:10.3762/bjoc.19.35

• , respectively. This reaction was also tolerant of a 2-naphthyl group, the palladium-catalyzed trifluromethylthiolation afforded the corresponding product 8h in 76% yield. Also, the 2,4-dimethoxylated substrate 7g and the benzothiophene derivative 7i were successfully trifluoromethylthiolated in 76% and 63

Strategies to access the [5-8] bicyclic core encountered in the sesquiterpene, diterpene and sesterterpene series

• Cécile Alleman,
• Charlène Gadais,
• Laurent Legentil and
• François-Hugues Porée

Beilstein J. Org. Chem. 2023, 19, 245–281, doi:10.3762/bjoc.19.23

• the stereogenic centers formed during the cascade cyclization was secured by the use of benzothiophene-based TADDOL thiol 166 as chiral catalyst. They obtained in one single step a 5.3:1 and 3.4:1 diastereomeric ratio for C14 and C15, respectively, while forming the desired trans [5-8] ring junction

Lewis acid-catalyzed Pudovik reaction–phospha-Brook rearrangement sequence to access phosphoric esters

• Jin Yang,
• Dang-Wei Qian and
• Shang-Dong Yang

Beilstein J. Org. Chem. 2022, 18, 1188–1194, doi:10.3762/bjoc.18.123

• heterocycle, such as a benzothiophene (in 1l) or a benzofuran unit (in 1m), could smoothly be transformed into the desired products 3al and 3am, respectively, in moderate yield. Phosphinates 3an and 3ao could both be prepared under this Pudovik reaction–phospha-Brook rearrangement sequence in moderate to good

Electrochemical vicinal oxyazidation of α-arylvinyl acetates

• Yi-Lun Li,
• Zhaojiang Shi,
• Tao Shen and
• Ke-Yin Ye

Beilstein J. Org. Chem. 2022, 18, 1026–1031, doi:10.3762/bjoc.18.103

• ), chloro (16), and bromo (17), proceeded with the anticipated reactivity less efficiently (30–48% yields). The presence of other electron-withdrawing groups, such as CO2Me (18) and OCF3 (19), exhibited similar negative effects on the reaction yields. Naphthalene (20), thiophene (21), benzothiophene (22

Introducing a new 7-ring fused diindenone-dithieno[3,2-b:2',3'-d]thiophene unit as a promising component for organic semiconductor materials

• Valentin H. K. Fell,
• Joseph Cameron,
• Alexander L. Kanibolotsky,
• Eman J. Hussien and
• Peter J. Skabara

Beilstein J. Org. Chem. 2022, 18, 944–955, doi:10.3762/bjoc.18.94

• been applied in various different molecules, exhibiting outstanding performances in certain applications. The highest hole mobility for organic semiconductors was achieved for thin, crystalline films of 2,7-dioctyl[1]benzothieno[3,2-b][1]-benzothiophene (8), shown in Figure 3, achieving a maximum hole

• had sizes of ca. 100 nm, while the crystallites in films obtained by on-centre spin-coating had smaller sizes of ca. 20 nm. The same core alkylated on only one side resulted in the asymmetric 2-tridecyl[1]benzothieno[3,2-b][1]-benzothiophene (9) [28]. In polycrystalline films obtained by thermal

• . EtH-T-DI-DTT (1). Previously published, ‘bent’ diindenodithienothiophenes [16][24][25]. With crystalline films of 2,7-dioctyl[1]benzothieno[3,2-b][1]-benzothiophene (8), obtained by off-centre spin-coating, Bao et al. could obtain remarkable OFET hole mobilities of up to 43 cm2 V−1 s−1 [27]. An

α-Ketol and α-iminol rearrangements in synthetic organic and biosynthetic reactions

• Scott Benz and
• Andrew S. Murkin

Beilstein J. Org. Chem. 2021, 17, 2570–2584, doi:10.3762/bjoc.17.172

• heteroarenes were much poorer, with pyrroles and thiophenes giving yields of ≈20% or less and benzofuran and benzothiophene failing to produce any product. Interestingly, a cyclopentanone-derived substrate (120) failed to yield the corresponding α-amino cyclohexanone 121 under the standard conditions used for

Advances in mercury(II)-salt-mediated cyclization reactions of unsaturated bonds

• Sumana Mandal,
• Raju D. Chaudhari and
• Goutam Biswas

Beilstein J. Org. Chem. 2021, 17, 2348–2376, doi:10.3762/bjoc.17.153

• al. reported a Hg(II) chloride-mediated cyclization reaction of 2-alkynylphenyl alkyl sulfoxide 179 to synthesize benzothiophene derivatives 180 with good yields [114]. In this case, the reaction was believed to proceed via the initial formation of metal carbenoids followed by a sequential C–H

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

• Renato L. Carvalho,
• Amanda S. de Miranda,
• Mateus P. Nunes,
• Roberto S. Gomes,
• Guilherme A. M. Jardim and
• Eufrânio N. da Silva Júnior

Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126

Helicene synthesis by Brønsted acid-catalyzed cycloaromatization in HFIP [(CF₃)₂CHOH]

• Takeshi Fujita,
• Noriaki Shoji,
• Nao Yoshikawa and
• Junji Ichikawa

Beilstein J. Org. Chem. 2021, 17, 396–403, doi:10.3762/bjoc.17.35

• , respectively. Furthermore, we demonstrated the synthesis of unsymmetrical thia[6]helicene 15 as a hetero[6]helicene synthesis (Scheme 6c). 3-Bromobenzothiophene 16 bearing a (1,3-dioxolan-2-yl)methyl group at the 2-position, which was readily prepared from benzothiophene, underwent Suzuki–Miyaura coupling with

Et₃N/DMSO-supported one-pot synthesis of highly fluorescent β-carboline-linked benzothiophenones via sulfur insertion and estimation of the photophysical properties

• Dharmender Singh,
• Vipin Kumar and
• Virender Singh

Beilstein J. Org. Chem. 2020, 16, 1740–1753, doi:10.3762/bjoc.16.146

• excellent light-emitting properties with quantum yields (ΦF) up to 47%. Keywords: benzothiophene; β-carboline; metal-free; photophysical properties; sulfur insertion; Introduction The pyrido[3,4-b]indole moiety, commonly referred as β-carboline, is the core unit of about one quarter of all natural

• ] which were attributed to the presence of an electrophilic as well as a nucleophilic functionality in this natural product [1]. Encouraged by the applications of β-carboline and benzothiophene motifs in medicinal and materials chemistry, it was envisaged to construct a β-carboline-based novel molecular

• hybrid containing the benzothiophene moiety (Figure 1) [57][58]. The present study was inspired by the recent findings of Nguyen and co-workers [59][60][61]. As a part of our ongoing project [62][63], we devised a simple and efficient one-pot practical approach for the construction of β-carboline

Recent synthesis of thietanes

• Jiaxi Xu

Beilstein J. Org. Chem. 2020, 16, 1357–1410, doi:10.3762/bjoc.16.116

• isobenzofuran-1-thiones 311 and 2-benzothiophene-1-thiones 314 with 2,3-dimethylbut-2-ene (215a) gave the corresponding spirothietanes 312 and 315 under photo irradiation. The spirothietanes 312 derived from 3-unsubstituted or 3-monosubstituted 1,3-dihydroisobenzofuran-1-thiones 311 were less stable and

Reaction of indoles with aromatic fluoromethyl ketones: an efficient synthesis of trifluoromethyl(indolyl)phenylmethanols using K₂CO₃/n-Bu₄PBr in water

• Thanigaimalai Pillaiyar,
• Masoud Sedaghati and
• Gregor Schnakenburg

Beilstein J. Org. Chem. 2020, 16, 778–790, doi:10.3762/bjoc.16.71

• -. 5-, 6-, and 7-azaindoles, 1g–j) provided the corresponding products in the range from 91–97% yield (3u–x). We applied the developed protocol to reactions of other heterocyclic systems such as indazole (4), benzimidazole (5), carbazole (6), benzofuran (7), and benzothiophene (8) with ketone 2a

Room-temperature Pd/Ag direct arylation enabled by a radical pathway

• Amy L. Mayhugh and
• Christine K. Luscombe

Beilstein J. Org. Chem. 2020, 16, 384–390, doi:10.3762/bjoc.16.36

• ) [11]. We hypothesized that other known palladium-catalyzed room-temperature direct arylation methods could proceed using a single electron process. Two such Pd/Ag methods were investigated: a method for benzothiophene arylation [11], and a method for fluoroarene coupling [10] (Scheme 4). First the

Combining the Ugi-azide multicomponent reaction and rhodium(III)-catalyzed annulation for the synthesis of tetrazole-isoquinolone/pyridone hybrids

• Gerardo M. Ojeda,
• Prabhat Ranjan,
• Pavel Fedoseev,
• Lisandra Amable,
• Upendra K. Sharma,
• Daniel G. Rivera and
• Erik V. Van der Eycken

Beilstein J. Org. Chem. 2019, 15, 2447–2457, doi:10.3762/bjoc.15.237

• rings, such as furan, benzofuran, pyrrole, benzopyrrole, thiophene, benzothiophene and naphthalene were also successfully synthesized (5d–l) in moderate to very good yields. The exceptions were the cases of indolopyridone 5i and thiazolopyridone 5k, the latter one could not be obtained even after many

Mono- and bithiophene-substituted diarylethene photoswitches with emissive open or closed forms

• A. Lennart Schleper,
• Mariano L. Bossi,
• Vladimir N. Belov and
• Stefan W. Hell

Beilstein J. Org. Chem. 2019, 15, 2344–2354, doi:10.3762/bjoc.15.227

• Optical Nanoscopy, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany 10.3762/bjoc.15.227 Abstract We present a new series of photochromic 1,2-bis(2-ethylbenzo[b]thiophen-3-yl)perfluorocyclopentenes with an oxidized benzothiophene core (O) or a nonoxidized one, decorated

• highly fluorescent “closed” forms combine photochromic and fluorescent entities in one molecule [1] and contain a perfluorocyclopentene bridge linking two 2-alkyl-1-benzothiophene-1,1-oxide residues with a C=C bond via C-3 and C-3′ atoms [2][3]. The “open” form of the DAE core (see graphical abstract and

• ” indicates oxidized benzothiophene units, and “Th1”/ “Th2” specify the number of thiophene units in the side chain. The coupling products were isolated via preparative HPLC in yields ranging from 21% to 75%. While in all cases the open forms of the diarylethenes were isolated, small amounts of SyOTh1 in its