Radical chemistry in polymer science: an overview and recent advances

• Zixiao Wang,
• Feichen Cui,
• Yang Sui and
• Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

• decades [28]. 1.3.1 Deactivation by reversible coupling: In 1982, Otsu and Yoshida [29] successfully polymerized styrene and MMA using dithiocarbamate compounds, and in 1986, Solomon et al. [30] published a patent entitled "Polymerization Processes and Polymers Produced Thereby", which led to the

One-pot synthesis of 2-arylated and 2-alkylated benzoxazoles and benzimidazoles based on triphenylbismuth dichloride-promoted desulfurization of thioamides

• Arisu Koyanagi,
• Yuki Murata,
• Shiori Hayakawa,
• Mio Matsumura and
• Shuji Yasuike

Beilstein J. Org. Chem. 2022, 18, 1479–1487, doi:10.3762/bjoc.18.155

• conventional methods; a notable alternative is the cyclodesulfurization, where intramolecular cyclization is combined with desulfurization from thioamide analogs such as thioureas, thiosemicarbazides, and dithiocarbamate salts under mild reaction conditions [10]. These synthesis methods are effective for

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

• employed as electron donor to generate EDA complex 137 with halogenated electron-acceptor aromatics 133, and then electron transfer occurs, affording intermediate 138. Finally, radical coupling gives rise to S-aryl dithiocarbamate product 135. In 2019, Liao and colleagues [13] utilized Katritzky salt 139

• complex. Synthesis of S-aryl dithiocarbamate product 135 initiated by an EDA complex. Mechanism of the synthesis of S-aryl dithiocarbamate product 135. Synthesis of thioether product 141 initiated by an EDA complex. Mechanism of the synthesis of borate product 144. Synthesis of boronation product 148

Recent advances in transition-metal-catalyzed incorporation of fluorine-containing groups

• Xiaowei Li,
• Xiaolin Shi,
• Xiangqian Li and
• Dayong Shi

Beilstein J. Org. Chem. 2019, 15, 2213–2270, doi:10.3762/bjoc.15.218

A novel three-component reaction between isocyanides, alcohols or thiols and elemental sulfur: a mild, catalyst-free approach towards O-thiocarbamates and dithiocarbamates

• András György Németh,
• György Miklós Keserű and
• Péter Ábrányi-Balogh

Beilstein J. Org. Chem. 2019, 15, 1523–1533, doi:10.3762/bjoc.15.155

• used as H2S donors in biological systems [18] and as intermediates in pharmaceutically significant organic syntheses [19][20]. The dithiocarbamate structural moiety can be found in biologically active molecules widely applied as fungicides, herbicides, pesticides [21][22][23][24][25] and in some cases

• -diimidazole or di-2-pyridyl thionocarbonate [57][58]. Decomposition of dithiocarbamate salts or thiocarbamates with various reagents offers a good alternative [59][60][61][62] as well, however, this approach first requires the synthesis of the appropriate precursor. Nitrile oxides react with thiourea to

• the desired product. Then we turned to the synthesis of dithiocarbamate 5a under the standard reaction conditions, but only the isothiocyanate intermediate was obtained (Table 2, entry 1). Thus a new optimization of the reaction conditions became necessary. Similarly to the previous methodology, the

Atom-economical group-transfer reactions with hypervalent iodine compounds

• Andreas Boelke,
• Peter Finkbeiner and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2018, 14, 1263–1280, doi:10.3762/bjoc.14.108

• potassium salt D and the release of potassium iodide. Reductive elimination then affords the second S-aryl dithiocarbamate 7’. If both aryl groups are not transferred to the same reaction centre in metal-mediated diarylations when unsymmetrical diaryliodonium salts are used as aryl-transfer reagents, poor

An overview of recent advances in duplex DNA recognition by small molecules

• Sayantan Bhaduri,
• Nihar Ranjan and
• Dev P. Arya

Beilstein J. Org. Chem. 2018, 14, 1051–1086, doi:10.3762/bjoc.14.93

One-pot three-component route for the synthesis of S-trifluoromethyl dithiocarbamates using Togni’s reagent

• Azim Ziyaei Halimehjani,
• Martin Dračínský and
• Petr Beier

Beilstein J. Org. Chem. 2017, 13, 2502–2508, doi:10.3762/bjoc.13.247

• afforded the corresponding isothiocyanate in high yield. A variable temperature NMR study revealed a rotational barrier of 14.6, 18.8, and 15.9 kcal/mol for the C–N bond in the dithiocarbamate moiety of piperidine, pyrrolidine, and diethylamine adducts, respectively. In addition, the calculated barriers of

• observed that the reaction of piperidine (1 equiv) with CS2 (2 equiv) in THF for 10 min followed by the addition of Togni's reagent I (1 equiv) and stirring for 2 hours at room temperature afforded the corresponding trifluoromethyl dithiocarbamate 4a in 25% isolated yield and the corresponding thiuram

• dithiocarbamate in THF, water or DMF the product ratio increased to 5:1 (Table 1, entries 13–15), the yield of 4a remained low compared to our one-pot three-component reaction in THF. In summary, stirring piperidine (1.5 equiv) and CS2 (1.5 equiv) in THF at room temperature for 10 min, followed by cooling to −78

Mechanochemical synthesis of thioureas, ureas and guanidines

• Vjekoslav Štrukil

Beilstein J. Org. Chem. 2017, 13, 1828–1849, doi:10.3762/bjoc.13.178

• dithiocarbamate salt in the first step, which can be isolated or desulfurized in situ to provide the isothiocyanate reagent. Without isolation, the isothiocyanate undergoes a reaction with the amine and produces the thiourea product. Such an approach for thiourea synthesis under mechanochemical ball milling

• dithiocarbamate salt 23 (Scheme 8a). In comparison with 24 h reactions carried out in solvents (CH2Cl2, THF, acetone, methanol, DMF, DMSO or neat CS2), the mechanochemical synthesis was rapid and furnished electron-rich isothiocyanates in high yields in 40–45 minutes (e.g., 24a–c). On the other hand, anilines

Phosphorus pentasulfide mediated conversion of organic thiocyanates to thiols

• Chandra Kant Maurya,
• Avik Mazumder and
• Pradeep Kumar Gupta

Beilstein J. Org. Chem. 2017, 13, 1184–1188, doi:10.3762/bjoc.13.117

• required by reported methods, and provides an attractive alternative to the existing methods for the conversion of organic thiocyanates to thiols. Keywords: dithiocarbamate; phosphorus pentasulfide; thiocyanate; thiol; toluene; Introduction Thiols constitute an important group of sulfur-containing

• thionation of the thiocyanate functionality with P2S5 to give the corresponding dithiocarbamate derivative which, in presence of residual phosphoric acid of P2S5, decomposes to give the corresponding thiol, in analogy with the acidic hydrolysis of S-thiocarbamates [21]. Although, we were not able to isolate

• the S,S-dithiocarbamate intermediate from the reaction between thiocyanate and P2S5, its formation was indirectly confirmed by treating benzyl S-thiocarbamate, synthesized separately [22], with P2S5 under similar reaction conditions to give the corresponding thiol (80%). It could be believed that

A novel method for heterocyclic amide–thioamide transformations

• Walid Fathalla,
• Ibrahim A. I. Ali and
• Pavel Pazdera

Beilstein J. Org. Chem. 2017, 13, 174–181, doi:10.3762/bjoc.13.20

• chlorination of the heterocyclic amides to afford the corresponding chloroheterocycles. Secondly, the chloroherocycles and N-cyclohexyl dithiocarbamate cyclohexylammonium salt were heated in chloroform for 12 h at 61 °C to afford heteocyclic thioamides in excellent yields. Keywords: heterocyclic amides

• ; heterocyclic thioamides; N-cyclohexyl dithiocarbamate cyclohexylammonium salt; novel thiating agent; thiation; Introduction Transforming heterocyclic amides into thioamides is an important task in organic synthesis. Earlier reports for this type of O/S conversions were achieved by several thiating reagents

• efficient method for the transformation of heterocyclic amides to heterocyclic thioamides gained great attention. The reaction of three molar equivalents of cyclohexylamine (1) with one molar equivalent of carbon disulfide in water typically afforded N-cyclohexyl dithiocarbamate cyclohexylammonium salt (2

[2.2]Paracyclophane derivatives containing tetrathiafulvalene moieties

• Laura G. Sarbu,
• Lucian G. Bahrin,
• Peter G. Jones,
• Lucian M. Birsa and
• Henning Hopf

Beilstein J. Org. Chem. 2015, 11, 1917–1921, doi:10.3762/bjoc.11.207

• (Figure 1). The molecular dimensions confirm the extensive p–π conjugation within the dithiocarbamate group; the N(1)–C(19) bond length is 1.341(3) Å, some 0.12 Å shorter than N(1)–C(20) and N(1)–C(21), which are essentially σ-bonds. The cyclophane group displays the usual indicators of strain (e.g

Photoswitchable precision glycooligomers and their lectin binding

• Daniela Ponader,
• Sinaida Igde,
• Marko Wehle,
• Katharina Märker,
• Mark Santer,
• David Bléger and
• Laura Hartmann

Beilstein J. Org. Chem. 2014, 10, 1603–1612, doi:10.3762/bjoc.10.166

• equiv of sugar azide, 20 mol % sodium ascorbate and 20 mol % CuSO4 per alkyne group were dissolved in DMF/H2O, added to the resin and shaken for 4 hours. Excess reagents as well as the copper catalyst were removed by washing with a 23 mM solution of sodium diethyl dithiocarbamate in DMF as well as water

• hours. After that, the resin was washed with a 23 mM solution of sodium diethyl dithiocarbamate in DMF, water, DMF and DCM. Fmoc cleavage: The Fmoc protecting group was cleaved by the addition of a solution of 25% piperidine in DMF three times for 5, 10 and 15 minutes, respectively. This was followed by

Spin state switching in iron coordination compounds

• Philipp Gütlich,
• Ana B. Gaspar and
• Yann Garcia

Beilstein J. Org. Chem. 2013, 9, 342–391, doi:10.3762/bjoc.9.39

• years ago by Cambi and co-workers. They prepared a great variety of dithiocarbamato complexes of iron(III), by varying the substituents at the dithiocarbamate ligands, and investigated their magnetic properties. From magnetic susceptibility measurements at room temperature they found that some of the

Stereoselective synthesis of tetrasubstituted alkenes via a sequential carbocupration and a new sulfur–lithium exchange

• Andreas Unsinn,
• Cora Dunst and
• Paul Knochel

Beilstein J. Org. Chem. 2012, 8, 2202–2206, doi:10.3762/bjoc.8.248

• starting from 2,2’-dibromobiphenyl. Thus, the performance of a double bromine–lithium exchange with BuLi (1.1 equiv, −78 °C, 0.25 h) followed by a quenching with tetramethylthiuram disulfide (1.1 equiv, −78 to 25 °C, 12 h) furnishes the dithiocarbamate 13 in 82% yield. Since the reduction to the free thiol

A general and facile one-pot process of isothiocyanates from amines under aqueous conditions

• Nan Sun,
• Bin Li,
• Jianping Shao,
• Weimin Mo,
• Baoxiang Hu,
• Zhenlu Shen and
• Xinquan Hu

Beilstein J. Org. Chem. 2012, 8, 61–70, doi:10.3762/bjoc.8.6

• generation of a dithiocarbamate salt from the amine substrate by reacting with CS2 followed by elimination to form the isothiocyanate product with cyanuric acid as the desulfurylation reagent. The choice of solvent is of decisive importance for the successful formation of the dithiocarbamate salt

• . Recently, a two-step approach, which was named reagent-promoted desulfurylation of dithiocarbamates strategy, has attracted much attention. In the context of this method, an amine is typically converted into a corresponding dithiocarbamate by reacting with CS2 in the presence of a base; and a subsequent

• , we speculated that it could also be effective and practical in the desulfurylation of dithiocarbamates to form isothiocyanates. Our initial study started with aniline (1, Scheme 1) to prepare phenyl isothiocyanate (4, Scheme 1) via N-phenyl dithiocarbamate (2-1, Scheme 1) followed by desulfurylation

Sexithiophenes as efficient luminescence quenchers of quantum dots

• Christopher R. Mason,
• Yang Li,
• Paul O’Brien,
• Neil J. Findlay and
• Peter J. Skabara

Beilstein J. Org. Chem. 2011, 7, 1722–1731, doi:10.3762/bjoc.7.202

• ) core/shell quantum dots was conducted to determine the effect of the Lewis base group in sexithiophenes 1a and 1b. The quantum dot CdSe core was prepared by the method of Cumberland et al. [25], and the ZnS shell was added using the dithiocarbamate precursor Zn(S2CNMeHex)2 [26]. The resulting dots

Asymmetric synthesis of tertiary thiols and thioethers

• Jonathan Clayden and
• Paul MacLellan

Beilstein J. Org. Chem. 2011, 7, 582–595, doi:10.3762/bjoc.7.68

• thioacetate in toluene proceeds faster at 55 °C (Scheme 4). The synthesis of the unnatural enantiomer of the natural product spirobrassinin has been achieved by substitution at a quaternary centre by a sulfur nucleophile [14]. Intramolecular cyclisation of a dithiocarbamate 13 allows isolation of 14 with