Synthesis, structure and π-expansion of tris(4,5-dehydro-2,3:6,7-dibenzotropone)

• Yongming Xiong,
• Xue Lin Ma,
• Shilong Su and
• Qian Miao

Beilstein J. Org. Chem. 2025, 21, 1–7, doi:10.3762/bjoc.21.1

• synthesized according to the procedures detailed in Supporting Information File 1. In this reaction, the first step of diazo–thioketone coupling occurred at 50 °C in THF, and the second step of desulfurization with triisopropyl phosphite occurred in refluxed toluene, giving diene 10 in a yield of 47%. The

Synthesis of indano[60]fullerene thioketone and its application in organic solar cells

• Yong-Chang Zhai,
• Shimon Oiwa,
• Shinobu Aoyagi,
• Shohei Ohno,
• Tsubasa Mikie,
• Jun-Zhuo Wang,
• Hirofumi Amada,
• Koki Yamanaka,
• Kazuhira Miwa,
• Naoyuki Imai,
• Takeshi Igarashi,
• Itaru Osaka and
• Yutaka Matsuo

Beilstein J. Org. Chem. 2024, 20, 1270–1277, doi:10.3762/bjoc.20.109

• converted to indano[60]fullerene thioketone (FIDS) in high yield by using Lawesson's reagent. Three compounds with different substituents in para position were successfully converted to the corresponding thioketones, showing that the reaction tolerates compounds with electron-donating and electron

• -withdrawing substituents. Computational studies with density functional theory revealed the unique vibrations of the thioketone group in FIDS. The molecular structure of FIDS was confirmed by single-crystal X-ray analysis. Bulk heterojunction organic solar cells using three evaporable fullerene derivatives

• (FIDO, FIDS, C60) as electron-acceptors were compared, and the open-circuit voltage with FIDS was 0.16 V higher than that with C60. Keywords: C60; evaporable fullerene derivatives; organic photovoltaics; organic solar cells; thioketone; Introduction Fullerene is a carbon allotrope that has attracted

Biological properties and conformational studies of amphiphilic Pd(II) and Ni(II) complexes bearing functionalized aroylaminocarbo-N-thioylpyrrolinate units

• Samet Poyraz,
• Samet Belveren,
• Sabriye Aydınoğlu,
• Mahmut Ulger,
• Abel de Cózar,
• Maria de Gracia Retamosa,
• Jose M. Sansano and
• H. Ali Döndaş

Beilstein J. Org. Chem. 2021, 17, 2812–2821, doi:10.3762/bjoc.17.192

• rotation of the thioketone carbon–N-pyrrolidine bond, are energetically accessible, in agreement with the two set of signals observed by 1H NMR spectroscopy (energy differences between conformers lower than 1 kcal·mol–1 in both cases). However, this equilibrium is strongly affected by the coordination to

Catalyzed and uncatalyzed procedures for the syntheses of isomeric covalent multi-indolyl hetero non-metallides: an account

• Ranadeep Talukdar

Beilstein J. Org. Chem. 2021, 17, 2102–2122, doi:10.3762/bjoc.17.137

• THF switched the product to thioketone 99 (Scheme 14). Refluxing the thioketones 99 again with phenylhydrazine hydrochloride in ethanol resulted in the desired bis(indol-3-yl)sulfides 98. On the other hand, the treatment of thioketones 99 with phenylhydrazine afforded the corresponding hydrazones 100

Recent synthesis of thietanes

• Jiaxi Xu

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

• underwent a thermal rearrangement to generate tricyclic isobenzofurans 313 through the ring-cleavage of the thietanes. It was assumed that the rearrangement was assisted through participation of the oxygen lone-pair electrons [17] (Scheme 57). The silicon-containing phenyl triphenylsilyl thioketone (316

• (trifluoromethyl)-1,3-dithietane (363) and styrenes 383 produced the [2 + 2] adducts 4-aryl-2,2-bis(trifluoromethyl)thietanes 384 and Diels–Alder adducts 385, which further reacted with another molecule of bis(trifluoromethyl)thioketone (381) to yield the double Diels–Alder adducts 385 and thiochromane derivatives

Ferrocenyl-substituted tetrahydrothiophenes via formal [3 + 2]-cycloaddition reactions of ferrocenyl thioketones with donor–acceptor cyclopropanes

• Grzegorz Mlostoń,
• Mateusz Kowalczyk,
• André U. Augustin,
• Peter G. Jones and
• Daniel B. Werz

Beilstein J. Org. Chem. 2020, 16, 1288–1295, doi:10.3762/bjoc.16.109

• thioketones to form nearly equal amounts of both diastereoisomeric tetrahydrothiophenes. A low selectivity was also observed in the reaction of a 2-phthalimide-derived cyclopropane with ferrocenyl phenyl thioketone. Keywords: [3 + 2]-cycloaddition reactions; donor–acceptor cyclopropanes; ferrocenyl

• , respectively [11][12][13][14][15]. Notably, in contrast to aryl/alkyl thioketones (e.g., thioacetophenone), their ferrocenyl analogs of type 8 (e.g., ferrocenyl phenyl thioketone (8a), diferrocenyl thioketone (8b), and ferrocenyl methyl thioketone (8c)) were stable compounds at ambient conditions and could be

• dicarboxylate (5a) and ferrocenyl phenyl thioketone (8a) in CH2Cl2 at room temperature using aluminum chloride (AlCl3) as a catalyst. The reaction was monitored by TLC, and was shown to be complete after 1 h. The crude reaction mixture was examined by 1H NMR, revealing the formation of a single product with

Tetrathiafulvalene – a redox-switchable building block to control motion in mechanically interlocked molecules

• Hendrik V. Schröder and
• Christoph A. Schalley

Beilstein J. Org. Chem. 2018, 14, 2163–2185, doi:10.3762/bjoc.14.190

• synthetic advance is the phosphite-mediated heterocoupling of 1,3-dithiol-2-thiones F and 1,3-dithiol-2-ones G which provides efficient access to TTFs with two differently substituted 1,3-dithiol rings in an efficient way [49]. Simple heating of both monomers (ketone and thioketone) in P(OMe)3 or P(OEt)3

A novel application of 2-silylated 1,3-dithiolanes for the synthesis of aryl/hetaryl-substituted ethenes and dibenzofulvenes

• Grzegorz Mlostoń,
• Paulina Pipiak,
• Róża Hamera-Fałdyga and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2017, 13, 1900–1906, doi:10.3762/bjoc.13.185

• Trimethylsilyldiazomethane (TMS-CHN2) reacts readily with hetaryl thioketones to give sterically crowded 2-trimethylsilyl-4,4,5,5-tetrahetaryl-1,3-dithiolanes with complete regioselectivity at −75 °C as well as at rt. Thiofluorenone, a relatively stable and highly reactive aryl thioketone, yields upon treatment with TMS

• ]. For example, in contrast to thiobenzophenone (1a), phenyl selenophen-2-yl thioketone (1b) does not form the corresponding 2,5-dihydro-1,3,4-thiadiazole of type 2, and even at −70 °C spontaneous elimination of N2 was observed. As products of this reaction, dimer 4 of the intermediate thiocarbonyl S

• ]. General Procedure for the one-pot synthesis of ethenes 9a–f: A hetaryl thioketone 1 (1 mmol) was dissolved in THF (2–3 mL) and the solution was cooled to 0 °C (ice bath). Then, the mixture was treated with small portions of an ethereal solution of TMS-CHN2 (2 M, 0.5 mL, 1 mmol). The reaction was complete

Dimerization reactions of aryl selenophen-2-yl-substituted thiocarbonyl S-methanides as diradical processes: a computational study

• Michael L. McKee,
• Grzegorz Mlostoń,
• Katarzyna Urbaniak and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2017, 13, 410–416, doi:10.3762/bjoc.13.44

• , Winterthurerstrasse 190, CH-8057 Zurich, Switzerland 10.3762/bjoc.13.44 Abstract An intriguing stepwise diradical mechanism of the dimerization of the reactive intermediate (thiocarbonyl S-methanide) appearing in the reaction of phenyl selenophen-2-yl thioketone with diazomethane was studied by means of

• , substituents located in 4-position of the phenyl ring influence the yield of 9 formed in a competitive reaction with the formal [2 + 3]-cycloaddition of 8 with the starting thioketone 10 leading to the sterically crowded 1,3-dithiolane 11. The structure of the dimer 9, confirmed by an X-ray analysis [13

Synthesis of ferrocenyl-substituted 1,3-dithiolanes via [3 + 2]-cycloadditions of ferrocenyl hetaryl thioketones with thiocarbonyl S-methanides

• Grzegorz Mlostoń,
• Róża Hamera-Fałdyga,
• Anthony Linden and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2016, 12, 1421–1427, doi:10.3762/bjoc.12.136

• 1,5-diradical as a key intermediate. The complete change of the reaction mechanism toward the concerted [3 + 2]-cycloaddition was observed in the reaction of a sterically crowded cycloaliphatic thiocarbonyl ylide with ferrocenyl methyl thioketone. Keywords: [3 + 2]-cycloadditions; 1,3-dithiolanes

• (4b), respectively, and diazomethane at –60 °C in THF solution [6] (Scheme 1). After addition of an equimolar amount of a ferrocenyl hetaryl thioketone 1, the reaction mixture was slowly warmed to room temperature. The crude mixture was examined by 1H NMR spectroscopy, and in all cases only one single

• series, the characteristic signals of H2C(5) appeared at 49.3–53.9 ppm, in agreement with literature data [13]. In an extension of the study with ferrocenyl hetaryl thioketones 1, an experiment with ferrocenyl methyl thioketone (1e) and thiocabonyl S-methanide 2c was performed under typical conditions

Diradical reaction mechanisms in [3 + 2]-cycloadditions of hetaryl thioketones with alkyl- or trimethylsilyl-substituted diazomethanes

• Grzegorz Mlostoń,
• Paulina Pipiak and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2016, 12, 716–724, doi:10.3762/bjoc.12.71

• products of the [3 + 2]-cycloaddition of the diazo dipole onto the C=S bond. The latter decompose only at higher temperature (ca. −40 °C) to generate thiocarbonyl S-isopropanide. In the absence of the starting thioketone, the corresponding thiiranes and/or ethene derivatives, formed from them via

• , leading to unusual dimers 5 of intermediate thiocarbonyl ylides of type 3c [22] (Scheme 2). In a competitive reaction, the latter react with the starting thioketone 1c to give 1,3-dithiolanes of type 6 which are, apparently, also formed via a diradical pathway, leading to the sterically crowded 4,4,5,5

• different result was observed in the reaction of 7a with di(thiophen-2-yl) thioketone (1d). In that case, the reaction at −75 °C afforded also the expected thiirane 8d as the major product, accompanied by small amounts of the corresponding alkene 9d. However, in that case 4,4,5,5-tetrasubstituted 1,3

Hetero-Diels–Alder reactions of hetaryl and aryl thioketones with acetylenic dienophiles

• Grzegorz Mlostoń,
• Paulina Grzelak,
• Maciej Mikina,
• Anthony Linden and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2015, 11, 576–582, doi:10.3762/bjoc.11.63

• ongoing studies on thioketones, we reported recently on selected reactions of new symmetrical and non-symmetrical hetaryl thioketones [16]. Among others, the reactions of 2a with phenyl thien-2-yl thioketone as well as with bis(thien-2-yl) thioketone were described. The goal of the present study is to

• determination (Figure 1). The analogous reactions of 2a with bis(N-methylpyrrol-2-yl) thioketone (1d) afforded the pyrrolo[2,3-c]thiopyran derivative 4d in modest yield (35%) (Scheme 2). In the case of bis(thien-2-yl) thioketone (1e), the reaction with 2a was carried out in toluene at room temperature under a

• were also performed with 1e (16% yield of 5d) and 1f (33% yield of 5e), respectively; thioketone 1g was not tested under high pressure. However, attempted isolations of both 5e and 5f were unsuccessful as the products underwent decomposition upon chromatographic work-up. The experiment performed with

On the strong difference in reactivity of acyclic and cyclic diazodiketones with thioketones: experimental results and quantum-chemical interpretation

• Andrey S. Mereshchenko,
• Alexey V. Ivanov,
• Viktor I. Baranovskii,
• Grzegorz Mloston,
• Ludmila L. Rodina and
• Valerij A. Nikolaev

Beilstein J. Org. Chem. 2015, 11, 504–513, doi:10.3762/bjoc.11.57

• case of thioketone 2b, all calculations were performed for the gas phase. Reactions with thiobenzophenone (2a) By comparison with the literature data [16][17][18], one can assume that the multistep reactions of DDC 1a–d and thione 2a are initiated by 1,3-cycloaddition of the diazogroup with the C=S

• , PBE1PBE, Table 1, entry 1) corresponds to the reaction of the most reactive diazoacetylacetone (1a) with thioketone 2a, which was completed at room temperature over several days (and in good yields of oxathiole 3a of up to 80%). The intermediate values of ΔG1# (30.8–31.3 kcal·mol−1, PBE1PBE, Table 1

• stereochemical and/or the energetic parameters of the process. Reactions with 2,2,4,4-tetramethyl-3-thioxocyclobutanone (2b) The mechanism of the 1,3-dipolar cycloaddition of diazo compounds 1 with aliphatic thioketone 2b was assumed to be similar to their reaction with aromatic thione 2a (Scheme 2). Thus, the

Less reactive dipoles of diazodicarbonyl compounds in reaction with cycloaliphatic thioketones – First evidence for the 1,3-oxathiole–thiocarbonyl ylide interconversion

• Valerij A. Nikolaev,
• Alexey V. Ivanov,
• Ludmila L. Rodina and
• Grzegorz Mlostoń

Beilstein J. Org. Chem. 2013, 9, 2751–2761, doi:10.3762/bjoc.9.309

• compounds. Preliminary experiments, however, showed that under standard conditions, a cycloaddition of diazodimedone and dimethyl diazomalonate with thiobenzophenone did not occur [5][6]. On the other hand, recent studies showed that the [3 + 2]-cycloaddition of this thioketone with many diazodicarbonyl

• carried out either at room temperature or at 80 °C depending on the reactivity and the stability of diazodicarbonyl compound 2 and thioketone 1. In general, ca. 5% excess of 2 was applied in order to enable a visual determination of the completion of the reaction based on the disappearance of the

• intensive red or orange color of thioketone 1. In order to enhance the concentration of the reagents and thereby increase the rate of the reaction, experiments with liquid diazocompounds 2a,c–e,h and i and thioketone 1a were carried out under solvent-free conditions. On the other hand, reactions of solid

Synthesis of 2,3-dihydronaphtho[2,3-d][1,3]thiazole-4,9-diones and 2,3-dihydroanthra[2,3-d][1,3]thiazole-4,11-diones and novel ring contraction and fusion reaction of 3H-spiro[1,3-thiazole-2,1'-cyclohexanes] into 2,3,4,5-tetrahydro-1H-carbazole-6,11-diones

• Lidia S. Konstantinova,
• Kirill A. Lysov,
• Ljudmila I. Souvorova and
• Oleg A. Rakitin

Beilstein J. Org. Chem. 2013, 9, 577–584, doi:10.3762/bjoc.9.62

• thioketone by the action of sulfur monochloride in the presence of DABCO [18][19]. A plausible mechanism includes the addition of complex 8 to the activated methylene group with formation of S-S-DABCO derivative 12 followed by elimination of a sulfur atom and an HCl molecule [19]. We believe that naphtho- (1

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