Enhancing structural diversity of terpenoids by multisubstrate terpene synthases

• Min Li and
• Hui Tao

Beilstein J. Org. Chem. 2024, 20, 959–972, doi:10.3762/bjoc.20.86

• synthase (CLS) from Cannabis sativa and 5-epi-aristolochene synthase (TEAS) from Nicotiana tabacum were incubated with 11 synthetic prenyl analogs with ether, thioether, alkyne, or phenyl groups, and six of them (60–65) were converted into several novel monoterpenoids 66–71 [46] (Figure 5). In addition to

Regioselective quinazoline C2 modifications through the azide–tetrazole tautomeric equilibrium

• Dāgs Dāvis Līpiņš,
• Andris Jeminejs,
• Una Ušacka,
• Anatoly Mishnev,
• Māris Turks and
• Irina Novosjolova

Beilstein J. Org. Chem. 2024, 20, 675–683, doi:10.3762/bjoc.20.61

• , thioether substituents were installed in the presence of K2CO3. For alkylthiols, DMF was used, but arylthiols required milder conditions with MeOH and cooling to acquire regioselectivity to the C4 position which resulted in yields up to 91%. Oxidation with purified mCPBA (commercial mCPBA with 68% purity

Switchable molecular tweezers: design and applications

• Pablo Msellem,
• Maksym Dekthiarenko,
• Nihal Hadj Seyd and
• Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

• allosteric catalytic regulation (Figure 21). Mirkin and co-workers reported the symmetric tweezers 40 based on a Rh(I) complex with a phosphine and a labile thioether site and Cr(III)–salen arms as catalytic sites for the asymmetric ring opening of cyclohexene oxide by TMSN3 [80]. The closed tweezers showed

• higher activity and enantioselectivity due to the preorganization of the Cr(III) catalytic centers enabling bimetallic catalysis compared to the more flexible arrangement of the salen in the open form. The tweezers could be opened by breaking the thioether–rhodium bond with a combination of Cl− and CO

• metalloporphyrin arms [83] or larger assemblies [78]. In particular, remarkable double tweezers (or triple-decker catalysts) 41 have been developed (Figure 22). These tweezers consist of two Rh(I) complexes, wherein a catalytically active metal Al(III)–salen arm is shared on the phosphine thioether ligand side

Pseudallenes A and B, new sulfur-containing ovalicin sesquiterpenoid derivatives with antimicrobial activity from the deep-sea cold seep sediment-derived fungus Pseudallescheria boydii CS-793

• Zhen Ying,
• Xiao-Ming Li,
• Sui-Qun Yang,
• Hong-Lei Li,
• Xin Li,
• Bin-Gui Wang and
• Ling-Hong Meng

Beilstein J. Org. Chem. 2024, 20, 470–478, doi:10.3762/bjoc.20.42

• alkaloids containing an unprecedented spiro[bicyclo[2.2.2]octane-diketopiperazine] skeleton, chevalinulins A and B, and the first cytochalasin homodimer containing a thioether bridge, verruculoid A, were identified from deep-sea cold seeps-derived fungi and were described to have potent proangiogenic and

• . proliferatum with MIC values of 2, 4, and 4 μg/mL, respectively. Conclusion In conclusion, two new ovalicin sesquiterpenoid derivatives with a thioether bond, namely, pseudallenes A (1) and B (2), together with three known analogues 3–5, were isolated and identified from the cold seep-derived fungus P. boydii

Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• corresponding bis(thiophenyl) thioether, which then underwent successive bromination and iodination to give intermediate 18. Next, a two-fold Suzuki–Miyaura cross-coupling occurring chemoselectively on the iodinated positions allowed the symmetric extension of the hydrocarbon scaffold, with the insertion of two

Nucleophilic functionalization of thianthrenium salts under basic conditions

• Xinting Fan,
• Duo Zhang,
• Xiangchuan Xiu,
• Bin Xu,
• Yu Yuan,
• Feng Chen and
• Pan Gao

Beilstein J. Org. Chem. 2024, 20, 257–263, doi:10.3762/bjoc.20.26

• investigate simple alkylamines (2s and 2t) as the substrates. In doing so, we could not isolate the corresponding amination products 3as and 3at. To showcase the practical utility of our metal-free thioether formation process, we conducted a 5.0 mmol scale reaction and obtained the target product 3aa in 69

Copper-promoted C5-selective bromination of 8-aminoquinoline amides with alkyl bromides

• Changdong Shao,
• Chen Ma,
• Li Li,
• Jingyi Liu,
• Yanan Shen,
• Chen Chen,
• Qionglin Yang,
• Tianyi Xu,
• Zhengsong Hu,
• Yuhe Kan and
• Tingting Zhang

Beilstein J. Org. Chem. 2024, 20, 155–161, doi:10.3762/bjoc.20.14

• probable mechanism is proposed. As shown in Scheme 5, ethyl bromoacetate (2a) undergoes attack by the dipolar aprotic solvent DMSO to afford the intermediate A. This intermediate then reacts with the bromine anion to give intermediate B. Dimethylsulfonium bromide or dimethyl thioether/molecular bromine

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

• ) produced successively the lyso derivative 10.8 and the acetylated compound 10.9. The suppression of the ether function in position sn-1 of PAF or its replacement by a thioether function were also reported in 1984 with the aim to identify new compounds that could modulate platelet aggregation or featuring

• ) where the molecular structure is altered. However, the incorporation of a saccharide unit or an inositol moiety is included in subsequent sections. Modulation sn-1: In 1986, Morris-Natschke et al. [129][130] reported a racemic synthesis of thioether analogues of edelfosine using thioglycerol as

• iodomethane to give 26.2. 26.3 was isolated after the deprotection of the primary alcohol with BF3. Then, the installation of the phosphocholine polar head used POCl3 and choline tosylate to produce in low yield the phosphocholine thioether lipid 26.4. In this study, the authors reported that compound 26.4

Dipeptide analogues of fluorinated aminophosphonic acid sodium salts as moderate competitive inhibitors of cathepsin C

• Karolina Wątroba,
• Małgorzata Pawełczak and
• Marcin Kaźmierczak

Beilstein J. Org. Chem. 2023, 19, 434–439, doi:10.3762/bjoc.19.33

• ]. Based on its structure, many other inhibitors have been developed, such as vinyl sulfones, fluoromethyl ketones, and semicarbazides [8][9]. These inhibitors covalently bind to the nucleophilic thiol group of Cys234 in the active site of cathepsin C via a thioether bond. Phosphonates have been identified

Combretastatins D series and analogues: from isolation, synthetic challenges and biological activities

• Jorge de Lima Neto and
• Paulo Henrique Menezes

Beilstein J. Org. Chem. 2023, 19, 399–427, doi:10.3762/bjoc.19.31

• -unsaturated ester 42. Conversion of the installed alkene to the corresponding thioether followed by the reduction of the ester moiety using DIBAL gave the compound 43, which was subjected to a Stille coupling reaction [38] to yield compound 45. Hydrogenation reaction in the presence of metallic Mg [39

• ions. Further demethylation [40] and oxidation of the thioether followed by thermal elimination of the intermediate sulfoxide gave 2 in 98% yield after two steps (Scheme 7). The authors also achieved the synthesis of (±)-1 from combretastatin D-2 (2). Protection of the hydroxy group in compound 2 using

• (129) followed by the reduction [61] of the aldehyde gave the corresponding benzyl alcohol 131 in 76% yield. Deacetylation in the presence of hydrazine [62] followed by intramolecular thioetherification led to the macrocycle 133. Finally, the oxidation of the obtained thioether to the corresponding

1,4-Dithianes: attractive C2-building blocks for the synthesis of complex molecular architectures

• Bram Ryckaert,
• Ellen Demeyere,
• Frederick Degroote,
• Hilde Janssens and
• Johan M. Winne

Beilstein J. Org. Chem. 2023, 19, 115–132, doi:10.3762/bjoc.19.12

• co-workers could offer more opportunities here (Scheme 7) [43][44]. Furthermore, some recently reported photoredox-catalyzed thioether (C–H) alkylation and heteroarylation reactions developed by Alfonzo and Hande have demonstrated the use of 1,4-dithianes as viable substrates in such attractive bond

Practical synthesis of isocoumarins via Rh(III)-catalyzed C–H activation/annulation cascade

• Qian-Ci Gao,
• Yi-Fei Li,
• Jun Xuan and
• Xiao-Qiang Hu

Beilstein J. Org. Chem. 2023, 19, 100–106, doi:10.3762/bjoc.19.10

• , trifluoromethyl and nitro substituents, were retained unchanged in the final products (3ja, 3ka, 3ma, and 3na). Also the strongly coordinating thioether substituent proved to be suitable for this protocol, providing the desired product 3ea in 76% yield. Moreover, under the standard conditions, 3-thienyl and 2

Peptide stapling by late-stage Suzuki–Miyaura cross-coupling

• Hendrik Gruß,
• Rebecca C. Feiner,
• Ridhiwan Mseya,
• David C. Schröder,
• Michał Jewgiński,
• Kristian M. Müller,
• Rafał Latajka,
• Antoine Marion and
• Norbert Sewald

Beilstein J. Org. Chem. 2022, 18, 1–12, doi:10.3762/bjoc.18.1

• ], disulfide- [13], thioether- [14][15][16][17][18][19][20], triazole- [21][22], oxime- [23] and hydrazone formation [24] as well as multicomponent reactions such as the Ugi- or Petasis reaction [25][26][27][28][29][30][31][32]. The content of helicity can moreover be changed by the introduction of a photo

• Supporting Information File 1, Figure S4). As a conclusion from those experiments, it was hypothesised that the linker might be too rigid resulting in a distorted structure, which has also been previously reported for thioether cross-linked cysteines bearing a biphenyl template within the staple [20]. Hence

Copper-catalyzed monoselective C–H amination of ferrocenes with alkylamines

• Zhen-Sheng Jia,
• Qiang Yue,
• Ya Li,
• Xue-Tao Xu,
• Kun Zhang and
• Bing-Feng Shi

Beilstein J. Org. Chem. 2021, 17, 2488–2495, doi:10.3762/bjoc.17.165

• %), largely due to the poison of copper catalyst by thioether. Acyclic amines were also tested and the amination products were obtained in low yields (4n, 18%; 4o, 15%). Unfortunately, primary amines and anilines were completely inert. Encouraged by the above results, we further tried to synthesize ferrocene

Enantioenriched α-substituted glutamates/pyroglutamates via enantioselective cyclopropenimine-catalyzed Michael addition of amino ester imines

• Zara M. Seibel,
• Jeffrey S. Bandar and
• Tristan H. Lambert

Beilstein J. Org. Chem. 2021, 17, 2077–2084, doi:10.3762/bjoc.17.134

• handles for derivatization and so represent important achievements for this method. In terms of additional functionality, we found that a thioether substrate could be engaged with reasonably good efficiency and enantioselectivity (Table 2, entry 11). On the other hand, while a nitrile was compatible with

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

Chemical approaches to discover the full potential of peptide nucleic acids in biomedical applications

• Nikita Brodyagin,
• Martins Katkevics,
• Venubabu Kotikam,
• Christopher A. Ryan and
• Eriks Rozners

Beilstein J. Org. Chem. 2021, 17, 1641–1688, doi:10.3762/bjoc.17.116

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

Synthesis of bis(aryloxy)fluoromethanes using a heterodihalocarbene strategy

• Carl Recsei and
• Yaniv Barda

Beilstein J. Org. Chem. 2021, 17, 813–818, doi:10.3762/bjoc.17.70

• , fluoromethylene acetals. In the course of preparing synthetic samples of trace impurities in the herbicide pyroxasulfone, we were confronted with the problem of generating a bis(aryloxy)fluoromethane. Our intended route to structure 1 (Scheme 1) required the oxidation of bis-thioether 2, derived in turn from

• , we completed the radical bromination of 4 to produce 3 (Scheme 5), which was used to deliver the penultimate bis-thioether 2, with oxidation to 1 giving the target impurity structure as anticipated, with a combined yield for the three transformations from 4 to 1 of 42%. The synthesis of 4 was also

Synthetic reactions driven by electron-donor–acceptor (EDA) complexes

• Zhonglie Yang,
• Yutong Liu,
• Kun Cao,
• Xiaobin Zhang,
• Hezhong Jiang and
• Jiahong Li

Beilstein J. Org. Chem. 2021, 17, 771–799, doi:10.3762/bjoc.17.67

• between radicals was carried out, affording thioether derivative 132 (Scheme 46). It has been proved by UV–vis spectroscopy and TDDFT calculations that the EDA complex was formed between an electron-rich mercaptan anion and electron-deficient aryl halides. Most importantly, this approach can be

• and thiobenzoic acid (140) to form an EDA complex, providing thioether derivative 141 with DIPEA as an organic base additive (Scheme 49). This reaction offers a novel and simple approach for the synthesis of α-mercapto acid derivatives under mild reaction conditions and demonstrates strong

• compatibility to the functional group. In addition, a gram-scale reaction also gives the desired thioether product in a yield of 99%. The construction of C–B bonds The C–B bond can be converted into a wide range of other functional groups by the conversion of alkyl borane [70][71][72]. Hence, it has become

Benzothiazolium salts as reagents for the deoxygenative perfluoroalkylthiolation of alcohols

• Armin Ariamajd,
• Nils J. Gerwien,
• Benjamin Schwabe,
• Stefan Dix and
• Matthew N. Hopkinson

Beilstein J. Org. Chem. 2021, 17, 83–88, doi:10.3762/bjoc.17.8

• perfluoroalkylthiolation. Thus, 4-nitrobenzyl alcohol (2a) was reacted with 1.25 equivalents of BT-SC2F5 and 2 equivalents of NEt(iPr)2 in MeCN for 2 h at rt. The analysis of the crude reaction mixture by NMR revealed the formation of two products: the desired (pentafluoroethyl) thioether 3a in 78% NMR yield and a second

• be effectively suppressed by conducting the reaction at −40 °C. Under these conditions, the desired (pentafluoroethyl) thioether 3a was obtained in 99% NMR yield (91% isolated yield, Table 1, entry 2). At this stage, we were ready to evaluate the relative efficiency of different

• was observed upon increasing the RF chain length (Table 1, entries 2–5). For example, thionoester 8a was generated as a significant side product (26% NMR yield) when using BT-SC5F11, while thioether 9a and thionoester 10a were provided in almost equal amounts when BT-SC8F17 was reacted with 2a. The

Pauson–Khand reaction of fluorinated compounds

• Jorge Escorihuela,
• Daniel M. Sedgwick,
• Alberto Llobat,
• Mercedes Medio-Simón,
• Pablo Barrio and
• Santos Fustero

Beilstein J. Org. Chem. 2020, 16, 1662–1682, doi:10.3762/bjoc.16.138

• testing a variety of reaction conditions. More complex biorelevant examples such as isatin derivatives were also suitable substrates, affording the corresponding spirocyclic derivatives, albeit in low yields (Scheme 21) [59]. Unfortunately, thioether and sulfone-based linkers were unsuitable in this

Synthesis of six-membered silacycles by borane-catalyzed double sila-Friedel–Crafts reaction

• Yafang Dong,
• Masahiko Sakai,
• Kazuto Fuji,
• Kohei Sekine and
• Yoichiro Kuninobu

Beilstein J. Org. Chem. 2020, 16, 409–414, doi:10.3762/bjoc.16.39

• of phenothiasilin 3l that was obtained in 93% yield starting from diaryl thioether 1g. N-(Benzyl)methylamine-substituted diaryl thioether 1h was also transformed into phenothiasilin 3m in 58% yield. The corresponding six-membered silacycles were not formed using N-aryl-bridged biaryls as substrates

• . Synthetic methods of six-membered silacyclic compounds. Scope of dihydrosilanes. Conditions: a: conditions B (Table 1, entry 5); b: conditions A (Table 1, entry 3). Scope of diaryl ether and diaryl thioether derivatives. Conditions: a: conditions B (Table 1, entry 5); b: conditions A (Table 1, entry 3). c

Architecture and synthesis of P,N-heterocyclic phosphine ligands

• Wisdom A. Munzeiwa,
• Bernard Omondi and
• Vincent O. Nyamori

Beilstein J. Org. Chem. 2020, 16, 362–383, doi:10.3762/bjoc.16.35

• for its ability to undergo ligand transfer reactions. Ethylene sulfide has also been used as precursor for the synthesis of phosphine ligands. Kuang et al. synthesized a thioether-functionalized pyridine-based diphosphine ligand starting from diphenylphosphine and ethylene sulfide (Scheme 9) [70

• ligands. Synthesis of diphosphine pyrrole ligands. Synthesis of 4,5-diazafluorenylphosphine ligands. Synthesis of thioether-containing pyridyldiphosphine ligands starting from ethylene sulfide and diphenylphosphine. Synthesis of monoterpene-derived phosphine pyridine ligands. Synthesis of N

Synthesis of 3-alkenylindoles through regioselective C–H alkenylation of indoles by a ruthenium nanocatalyst

• Abhijit Paul,
• Debnath Chatterjee,
• Srirupa Banerjee and
• Somnath Yadav

Beilstein J. Org. Chem. 2020, 16, 140–148, doi:10.3762/bjoc.16.16

• alkenylation of indole with n-butylacrylate in the presence of thioether ligands [32]. In the context of C–H activation reactions, the catalyst of choice has mostly been Pd [33][34]. However, as part of the search for newer and more cost-efficient catalysts, other transition metals, such as Ru, have also been