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

• ) was dissolved in anhydrous THF (30 mL) under argon atmosphere. A 1.6 M n-BuLi hexane solution (2.3 mL, 3.6 mmol) was slowly added dropwise to the solution at −78 °C, and the mixture was refluxed for 1 h. 3-Methyl-2-(perfluorocyclopent-1-en-1-yl)benzo[b]thiophene [69] (1.1 g, 3.6 mmol) dissolved in THF

N-Glycosides of indigo, indirubin, and isoindigo: blue, red, and yellow sugars and their cancerostatic activity

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2840–2869, doi:10.3762/bjoc.20.240

• . Thioisoindigo-N-glycosides The condensation of isatin-N-rhamnoside β-16a with 2,3-dihydrobenzo[b]thiophen-2-one (73), available in two steps from benzo[b]thiophene [61], afforded thioisoindigo-N-rhamnoside β-74a in 45% yield (Scheme 41) [60]. Like in the case of β-64a, deprotection proved to be unsuccessful

Synthesis of photo- and ionochromic N-acylated 2-(aminomethylene)benzo[b]thiophene-3(2Н)-ones with a terminal phenanthroline group

• Vladimir P. Rybalkin,
• Sofiya Yu. Zmeeva,
• Lidiya L. Popova,
• Irina V. Dubonosova,
• Olga Yu. Karlutova,
• Oleg P. Demidov,
• Alexander D. Dubonosov and
• Vladimir A. Bren

Beilstein J. Org. Chem. 2024, 20, 552–560, doi:10.3762/bjoc.20.47

• Physical and Organic Chemistry, Southern Federal University, Rostov-on-Don 344090, Russian Federation North Caucasus Federal University, Stavropol 355009, Russian Federation 10.3762/bjoc.20.47 Abstract A series of novel photo- and ionochromic N-acylated 2-(aminomethylene)benzo[b]thiophene-3(2Н)-ones with

• sequential addition of Fe2+ and AcO−, we synthesized N-acylated 2-(aminomethylene)benzo[b]thiophene-3(2Н)-ones with a terminal phenanthroline substituent and studied the spectral-luminescent, photochromic and ionochromic properties. The phenanthroline moiety was incorporated into the molecule due to the

• lists of bond lengths and bond angles are given in Tables S1–S4, Supporting Information File 3. Compound 3b had the structure of an O-acylated isomer and possessed an E-s-cis(S,N) conformation relative to the C(l)–C(9) bond (Figure 3). The benzo[b]thiophene fragment was planar, whereas the propionyl

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

• derivatives were synthesized. Benzyl ((4-chloro-6-(4-methylphenyl)thieno[2,3-d]pyrimidin-5-yl)methyl) allylphosphonate (44) was prepared in 87% yield from 4-chloro-3-(chloromethyl)-2-(4-methylphenyl)benzo[b]thiophene (42) and benzyl hydrogen allylphosphonate (43) via alkylation in the presence of Cs2CO3 in

• from 3-bromobut-3-en-1-yl ethenyl(phenyl)phosphinate and 2-bromophenylmethyl alk-1-enylphosphinates. Synthesis of thieno[2,3-d]pyrimidine-fused 2-hydroxy-1,2-oxaphosphonane 2-oxide from benzyl hydrogen allylphosphonate and 4-chloro-3-(chloromethyl)-2-(4-methylphenyl)benzo[b]thiophene. Synthesis of 3

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

• insertion and then oxidation (Scheme 54). This methodology was later successfully utilized for the total synthesis of raloxifene and benzo[b]thiophene derivatives [115]. Cyclization involving allenes (>C=C=C<) Hg(II) triflate salts had also been successfully employed for the arylallene 181 cyclization by

Synthesis of trifluoromethyl ketones by nucleophilic trifluoromethylation of esters under a fluoroform/KHMDS/triglyme system

• Yamato Fujihira,
• Yumeng Liang,
• Makoto Ono,
• Kazuki Hirano,
• Takumi Kagawa and
• Norio Shibata

Beilstein J. Org. Chem. 2021, 17, 431–438, doi:10.3762/bjoc.17.39

• effect on the yield of the reaction of 1g (Table 2, entries 3–6, 58–72%). Next, a range of common oxygen and sulfur-containing compounds such as furan, tetrahydrofuran, 1,4-dioxane, thiophene, benzo[b]thiophene, dibenzo[b,d]thiophene, and diphenylsulfane were also screened. These substances also have

Synthesis and highly efficient light-induced rearrangements of diphenylmethylene(2-benzo[b]thienyl)fulgides and fulgimides

• Vladimir P. Rybalkin,
• Sofiya Yu. Zmeeva,
• Lidiya L. Popova,
• Valerii V. Tkachev,
• Andrey N. Utenyshev,
• Olga Yu. Karlutova,
• Alexander D. Dubonosov,
• Vladimir A. Bren,
• Sergey M. Aldoshin and
• Vladimir I. Minkin

Beilstein J. Org. Chem. 2020, 16, 1820–1829, doi:10.3762/bjoc.16.149

• -isomers and of products of the photoinduced rearrangement completed by 1,5-H shift reaction, 3a,4-dihydronaphtho[2,3-c]furans(pyrroles) C, were established based on the data of 1H and 13C NMR spectroscopy and X-ray diffraction studies. Keywords: benzo[b]thiophene; fulgide; fulgimide; photorearrangement

• fulgides 3Z and 3E are shown in Figure 1 and Figure 2. Fulgide 3Z possesses Z-configuration at the double bond С(4)=С(5). The 3-methoxy-2-benzo[b]thiophene moiety in 3Z is planar and is almost coplanar with the planar furan-2,5-dione fragment (the dihedral angle is equal to 3.9°). The phenyl rings are

• -methoxy-2-benzo[b]thiophene moiety in 3E is rotated relative to the furan-2,5-dione fragment by an angle of 36.5°. The torsion angle of the phenyl ring Ph(C(15)–C(20)) relative to the furan-2,5-dione plane (41.5°) is almost twice lesser than that in 3Z, whereas the torsion angle of the phenyl ring Ph(C(21

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

• gel (CHCl3/MeOH 95:5, v/v) to afford the analytically pure product 2bA as orange solid in 74% yield (two step yield). One-pot experimental procedure for the synthesis of methyl 1-(benzo[b]thiophene-2-carbonyl)-9H-pyrido[3,4-b]indole-3-carboxylate (6C). To a stirred suspension of Cs2CO3 (0.182 g, 0.560

Copper-based fluorinated reagents for the synthesis of CF₂R-containing molecules (R ≠ F)

• Louise Ruyet and
• Tatiana Besset

Beilstein J. Org. Chem. 2020, 16, 1051–1065, doi:10.3762/bjoc.16.92

• oxazoles (17 examples, up to 87% yield) were difluoromethylated but a variety of other heteroarenes turned out to be suitable such as pyridine, imidazole, benzo[d]thiazole, benzo[b]thiophene, benzo[d]oxazole, thiazole and thiophene derivatives (Scheme 6). Copper-based CF2FG-containing reagents Besides the

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

• -temperature, Pd/Ag-catalyzed direct arylation systems are radical-mediated. This is in contrast to the commonly proposed two-electron mechanisms for direct arylation and appears to extend to other substrates such as benzo[b]thiophene and pentafluorobenzene. Keywords: direct arylation; indole; palladium

• mechanism has been recently supported by 13C and 2H KIE experiments for the arylation of benzo[b]thiophene, although at C3 [13]. In contrast to these pathways, the radical trap and dark experiments reported above indicate a hybrid Pd(I) radical species induced by visible light is involved in the catalytic

• iodobenzene. Moreover, other substrates such as benzo[b]thiophene and pentafluorobenzene appear to undergo a radical-mediated Pd/Ag room-temperature direct arylation. This is a useful insight for advancing the direct arylation knowledge base, and serves as inspiration for designing new polymerization systems

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

• 12 (Scheme 2) were prepared. The transformations leading to diarylethene cores 3 and 6 were carried out on a 10–100 mmol scale (Scheme 1). The iodination at positions 6 and 6' of benzo[b]thiophene residues has been reported [5][8]. Following those protocols, diiodides 5 and 8 were obtained in fairly

• same total number of thiophene rings (SyTh1→SyOTh1). All CFs showed several absorption bands, while nonoxidized DAEs have two distinct absorption bands in the visible range. The data in Figure 3 indicate that, contrary to the OF, both benzo[b]thiophene moieties (with side rings) interact and determine

N-Methylphthalimide-substituted benzimidazolium salts and PEPPSI Pd–NHC complexes: synthesis, characterization and catalytic activity in carbon–carbon bond-forming reactions

• Senem Akkoç,
• Yetkin Gök,
• İlhan Özer İlhan and
• Veysel Kayser

Beilstein J. Org. Chem. 2016, 12, 81–88, doi:10.3762/bjoc.12.9

• –NHC complex as catalyst resulted in low yields and conversions (Table 3, entries 9–12). The usage of the morpholinoethyl substituted benzimidazolium compound 4 with Pd(OAc)2 resulted in higher yields of 2-(4-nitrophenyl)benzo[b]thiophene compared to the usage of compounds 1–3. Generally, the PEPPSI Pd

Pyridylidene ligand facilitates gold-catalyzed oxidative C–H arylation of heterocycles

• Kazuhiro Hata,
• Hideto Ito,
• Yasutomo Segawa and
• Kenichiro Itami

Beilstein J. Org. Chem. 2015, 11, 2737–2746, doi:10.3762/bjoc.11.295

• reaction gave sterically congested heterobiaryl 3da in 17% yield (Table 2, entry 8). In the case of the reaction of indole 1e, 3-arylindole 3ea was exclusively obtained in 44% yield (Table 2, entry 9). On the other hand, arylation of benzo[b]thiophene (1f) mainly afforded 2-arylbenzothiophene 3fa along

Copper-promoted hydration and annulation of 2-fluorophenylacetylene derivatives: from alkynes to benzo[b]furans and benzo[b]thiophenes

• Yibiao Li,
• Liang Cheng,
• Xiaohang Liu,
• Bin Li and
• Ning Sun

Beilstein J. Org. Chem. 2014, 10, 2886–2891, doi:10.3762/bjoc.10.305

• reaction and its application in the synthesis of benzo[b]furan and benzo[b]thiophene derivatives is presented starting from readily available 2-fluorophenylacetylene derivatives. The key annulation step involves the hydration of the C–F bond of 2-fluorophenylacetylene derivatives followed by an

• intramolecular annulation to afford benzo[b]furan and benzo[b]thiophene derivatives. Moreover, structurally important 2,2'-bisbenzofuran scaffolds are provided in good yields. Keywords: annulation; benzo[b]furan; C–F activation; copper-promoted; heterocycle; Introduction The development of general and

• efficient methodologies for the synthesis of complex heterocycle skeletons has received much attention in the past decades. Among the most ubiquitous heterocyclic moieties in natural and bioactive products are the benzo[b]furan and benzo[b]thiophene units [1][2][3][4][5][6][7][8]. Despite the existence of

Silver and gold-catalyzed multicomponent reactions

• Giorgio Abbiati and
• Elisabetta Rossi

Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46

• synthetic strategy, a solution-phase parallel synthesis of 1,2-dihydroisoquinolines has been developed by Larock, providing a 105-membered library for biological assays [58]. Moreover, an extension to γ-ketoalkyne encompassed in diverse heterocyclic frameworks (quinoline, pyridine or benzo[b]thiophene) has

The regioselective synthesis of spirooxindolo pyrrolidines and pyrrolizidines via three-component reactions of acrylamides and aroylacrylic acids with isatins and α-amino acids

• Tatyana L. Pavlovskaya,
• Fedor G. Yaremenko,
• Victoria V. Lipson,
• Svetlana V. Shishkina,
• Oleg V. Shishkin,
• Vladimir I. Musatov and
• Alexander S. Karpenko

Beilstein J. Org. Chem. 2014, 10, 117–126, doi:10.3762/bjoc.10.8

• nonnatural α-amino acids [11][12][13], more than fifteen isatins [14], and 1,3-dipolarophiles, e.g. α,β-unsaturated ketones [15][16][17], maleimides [18][19], benzo[b]thiophene-1,1-dioxide [20], bis(arylmethylidene)acetones and -cycloalkanones [21][22], 1,4-naphthoquinone [23], arylidenemalonodinitriles [24

Ring-opening reaction of 2,5-dioctyldithieno[2,3-b:3',2'-d]thiophene in the presence of aryllithium reagents

• Hao Zhong,
• Jianwu Shi,
• Jianxun Kang,
• Shaomin Wang,
• Xinming Liu and
• Hua Wang

Beilstein J. Org. Chem. 2013, 9, 767–774, doi:10.3762/bjoc.9.87

• thiophene derivatives in the presence of n-BuLi, though it has been reported, does not draw as much attention as the ring opening of other heterocyclic compounds [6][7][8][9]. The limited number of reports include derivatives of benzo[b]thiophene [10][11][12], thieno[3,2-d]thiazole [10][11], and thieno[3,2

Synthesis, solid-state fluorescence properties, and computational analysis of novel 2-aminobenzo[4,5]thieno[3,2-d]pyrimidine 5,5-dioxides

• Kenichirou Yokota,
• Masayori Hagimori,
• Naoko Mizuyama,
• Yasuhisa Nishimura,
• Hiroshi Fujito,
• Yasuhiro Shigemitsu and
• Yoshinori Tominaga

Beilstein J. Org. Chem. 2012, 8, 266–274, doi:10.3762/bjoc.8.28

• -autoclave. Compound 3b was also synthesized by the reaction of 2a with 2-(diaminomethylene)benzo[b]thiophene-3(2H)-one 1,1-dioxide (4), which was easily obtained from 1a by using 28% ammonia in methanol under reflux. The reactions of 1a, 2a, and amines 5a–c (benzylamine, piperidine, and aniline) in pyridine

• ]pyrimidine 5,5-dioxides (3a–g), were synthesized in good yields by a convenient one-pot reaction of 2-[bis(methylsulfanyl)methylene]benzo[b]thiophene-3(2H)-one 1,1-dioxide (1a) with guanidine carbonate (2a) or (S)-methylisothiourea sulfate (2b) under reflux in pyridine. Benzo[4,5]thieno[3,2-d]pyrimidine

• Alq3 as the standard sample. The fluorescence of the standard sample and all subject compounds was measured at 272 nm excitation. Synthesis 2-Amino-4-(methylsulfanyl)benzo[4,5]thieno[3,2-d]pyrimidine 5,5-dioxide (3a): A mixture of 2-[bis(methylsulfanyl)methylene]benzo[b]thiophene-3(2H)-one 1,1-dioxide

An overview of the key routes to the best selling 5-membered ring heterocyclic pharmaceuticals

• Marcus Baumann,
• Ian R. Baxendale,
• Steven V. Ley and
• Nikzad Nikbin

Beilstein J. Org. Chem. 2011, 7, 442–495, doi:10.3762/bjoc.7.57

Redox-active tetrathiafulvalene and dithiolene compounds derived from allylic 1,4-diol rearrangement products of disubstituted 1,3-dithiole derivatives

• Filipe Vilela,
• Peter J. Skabara,
• Christopher R. Mason,
• Thomas D. J. Westgate,
• Asun Luquin,
• Simon J. Coles and
• Michael B. Hursthouse

Beilstein J. Org. Chem. 2010, 6, 1002–1014, doi:10.3762/bjoc.6.113

• ): 189.6, 138.8, 138.8, 138.6, 131.0, 129.1, 128.5, 127.7, 127.6, 127.3, 125.5, 123.2, 116.5; IR ν (cm−1) 3102, 1651, 1403, 1370, 1068, 875, 852, 828, 697; Anal. calculated for C13H6S4O: C, 50.95; H, 1.97; S, 41.85; found: C, 50.52, H, 1.62; S, 42.66. 5,6-ethylenedithio-4-(thiophen-2-yl)benzo[b]thiophene

• , 138.5, 136.9, 131.1, 129.2, 129.0, 127.2, 126.8, 126.4, 123.6, 122.7, 114.9, 30.9, 30.7; IR ν (cm−1) 3100, 2916, 1559, 1406, 1365, 1312, 1288, 1194, 1138, 853, 824. 769, 702; UV–vis, λmax = 376 nm, ε = 8000. Tetrabutylammonium bis[(4-thiophen-2-yl)benzo[b]thiophene-5,6-bis(thiolato)]nickel(II) (28) To a

A perfluorocyclopentene based diarylethene bearing two terpyridine moieties – synthesis, photochemical properties and influence of transition metal ions

• Falk Wehmeier and
• Jochen Mattay

Beilstein J. Org. Chem. 2010, 6, No. 53, doi:10.3762/bjoc.6.53

• ″), 156.1 (tpy2′,6′). EI-MS (70 eV, m/z, %): 257 (10, [tpy-C=CH]••+), 309 (34, [M−BO2C5H9]+), 335 (20, [M−C5H10O]••+), 406 (25, [M−CH2]+), 421 (100, [M]+). Synthesis of 3,3′-(perfluorocyclopent-1-ene-1,2-diyl)bis(2-methyl-6-(4-(2,2′:6′,2″-terpyridin-4′-yl)phenyl)benzo[b]thiophene) (10a) 400 mg (555 μmol

• ), −132.7 to −134.2 (m, 2 F, 4-CF2). ESI-MS (positive mode, CHCl3/MeCN, m/z): 1083 [M]+. HRMS: calc. for [C65H40F6N6S2+H]+: 1083.27328; found: 1083.27181. Synthesis of 3,3′-(perfluorocyclopent-1-ene-1,2-diyl)bis(2-methyl-6-(3-(2,2′:6′,2″-terpyridin-4′-yl)phenyl)benzo[b]thiophene) (10b) 120 mg (167 μmol) 3,3

• . After removal of the solvent under reduced pressure, the crude yellow product was purified by column chromatography (basic alumina, eluting with THF) to yield 105 mg (97 μmol, 58%) of 3,3′-(perfluorocyclopent-1-ene-1,2-diyl)bis(2-methyl-6-(3-(2,2′:6′,2″-terpyridin-4′-yl)phenyl)benzo[b]thiophene) (10b

The efficient synthesis of dibenzo[d,d′]benzo[1,2-b:4,3-b′]dithiophene and cyclopenta[1,2-b:4,3-b′]bis(benzo[d]thiophen)-6-one

• Zhihua Wang,
• Sheng Zhu,
• Jianwu Shi and
• Hua Wang

Beilstein J. Org. Chem. 2009, 5, No. 55, doi:10.3762/bjoc.5.55

• photolysis of RCH(SPh)2 (R = benzo[b]thiophene). However, a non-photochemical method for preparing 1 has, to the best of our knowledge, not been reported. In our work, with 3,3′-bis[benzo[b]thiophenyl] (3) [18] as starting material, 1 (see Figure 1) was synthesized efficiently via formylation and McMurry

Synthesis of thienyl analogues of PCBM and investigation of morphology of mixtures in P3HT

• Fukashi Matsumoto,
• Kazuyuki Moriwaki,
• Yuko Takao and
• Toshinobu Ohno

Beilstein J. Org. Chem. 2008, 4, No. 33, doi:10.3762/bjoc.4.33

• Fukashi Matsumoto Kazuyuki Moriwaki Yuko Takao Toshinobu Ohno Osaka Municipal Technical Research Institute, 1-6-50 Morinomiya, Joto-ku, Osaka 536-8553, Japan. 10.3762/bjoc.4.33 Abstract Novel [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) analogues containing benzo[b]thiophene (3a, 3b) and

• procedure [22], as shown in Scheme 1. First, benzo[b]thiophene and thieno[3,2-b]thiophenes were acylated by using SnCl4; the acylation was performed at low temperature as a safeguard against the high reactivity of the thienyl groups (yields: 1a; 15%, 1b; 46%, 1c; 74%, 1d; 33%). Glutaric acid monomethyl

• ester chloride was used as an acylation reagent in order to form the same structure as that of the butyric acid methyl ester contained in PCBM. The acylation of benzo[b]thiophene yielded 2- and 3-substituted compounds in a 1:3 ratio. These isomers were isolated with a recycling HPLC system using