[1,3]/[1,4]-Sulfur atom migration in β-hydroxyalkylphosphine sulfides

• Katarzyna Włodarczyk,
• Piotr Borowski and
• Marek Stankevič

Beilstein J. Org. Chem. 2020, 16, 88–105, doi:10.3762/bjoc.16.11

• Marie Curie-Skłodowska Sq., 20-031 Lublin, Poland 10.3762/bjoc.16.11 Abstract β-Hydroxyalkylphosphine sulfides undergo [1,3]- or [1,4]-sulfur atom phosphorus-to-carbon migration in the presence of Lewis or Brønsted acids. The direction of sulfur atom migration depends on the type of acid used for the

• the cleavage of one single bond between phosphorus and either carbon or oxygen atom, while the multiple bond remains intact. Herein, we present the results concerning an unusual transformation of β-hydroxyalkylphosphine sulfides, which undergo [1,3]- or [1,4]-rearrangement in the presence of an acid

• stereoselective manner, given that corresponding chiral substrates were used for the cyclization. The chiral compounds suitable for cyclization could be obtained by desymmetrization of phosphine sulfides (Scheme 3) [58]. In order to gain insight into the cationic cyclization of β-hydroxyalkylphosphine sulfides, a

A review of asymmetric synthetic organic electrochemistry and electrocatalysis: concepts, applications, recent developments and future directions

• Munmun Ghosh,
• Valmik S. Shinde and
• Magnus Rueping

Beilstein J. Org. Chem. 2019, 15, 2710–2746, doi:10.3762/bjoc.15.264

• aryl sulfides 40 to their corresponding sulfoxides 41 using poly(amino acid)-coated platinum electrodes with moderate yield and good to excellent enantiomeric excess (Scheme 17) [47][48]. Osa and co-workers, in 1994, made an important contribution in the area by developing an enantioselective method

• methyl sulfide using chemically modified graphite anode. Asymmetric oxidation of unsymmetric sulfides using poly(amino acid)-coated electrodes. Enantioselective, electocatalytic oxidative coupling on TEMPO-modified graphite felt electrode in the presence of (−)-sparteine. Asymmetric electrocatalytic

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

Friedel–Crafts approach to the one-pot synthesis of methoxy-substituted thioxanthylium salts

• Kenta Tanaka,
• Yuta Tanaka,
• Mami Kishimoto,
• Yujiro Hoshino and
• Kiyoshi Honda

Beilstein J. Org. Chem. 2019, 15, 2105–2112, doi:10.3762/bjoc.15.208

• salts has been developed. The reaction of diaryl sulfides with benzoyl chlorides in the presence of TfOH smoothly proceeded to give the desired thioxanthylium salts in good yields. In their UV–vis spectra, the maximum absorption wavelengths of methoxy-functionalized thioxanthylium salts were observed at

• voltammograms of thioxanthylium salts 3b and 4b. The representative synthesis of thioxanthylium salts. Optimization of the reaction conditionsa. Supporting Information Supporting Information File 112: Copies of 1H and 13C NMR spectra, procedures for the synthesis of diaryl sulfides and thioxanthylium 4

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

• in toxicity and fits to the tenets of green chemistry. Zinc in the form of its salts, complexes (chelated by mono/di/tri/tetradentate ligands), oxides and sulfides proved to be a promising and active catalyst for organic chemists in both homogeneous as well as heterogeneous reaction systems [23][59

Insertion of [1.1.1]propellane into aromatic disulfides

• Robin M. Bär,
• Gregor Heinrich,
• Martin Nieger,
• Olaf Fuhr and
• Stefan Bräse

Beilstein J. Org. Chem. 2019, 15, 1172–1180, doi:10.3762/bjoc.15.114

• , but has never been thoroughly investigated. In this study, we show that an UV initiated radical reaction can be used to synthesize symmetrically and unsymmetrically substituted BCP sulfides by reaction of [1.1.1]propellane (1) with disulfides. Depending on the ratio of 1 to the disulfide, only the BCP

• product (Scheme 4). The purification was possible by HPLC (reversed-phase) and the yield was significantly lower compared to the aromatic disulfides. Szeimies et al. also synthesized alkyl-substituted BCP and staffane sulfides with the previously described method (see optimization) in similar yields [27

• particularly interesting if the two sulfides of the product can be modified individually. This approach to unsymmetrically substituted BCPs will be further investigated. Optimization of the reaction conditions. The relative conversion was determined by GC–MS. The use of a radical initiator (di-tert-butyl

Synthesis of aryl cyclopropyl sulfides through copper-promoted S-cyclopropylation of thiophenols using cyclopropylboronic acid

• Emeline Benoit,
• Ahmed Fnaiche and
• Alexandre Gagnon

Beilstein J. Org. Chem. 2019, 15, 1162–1171, doi:10.3762/bjoc.15.113

• . The procedure operates under simple conditions to afford the corresponding aryl cyclopropyl sulfides in moderate to excellent yields. The reaction tolerates substitution in ortho-, meta- and para-substitution as well as electron-donating and electron-withdrawing groups. The S-cyclopropylation of a

• thiophenol was also accomplished using potassium cyclopropyl trifluoroborate. Keywords: aryl cyclopropyl sulfides; copper(II) acetate; copper catalysis; cyclopropylboronic acid; thiophenols; Introduction Aryl cyclopropyl sulfides are present in many biologically active compounds, mainly in their oxidized

• ]. Roniciclib, also named BAY 1000394, is a pan-cyclin-dependant kinase (CDK) inhibitor that contains an aryl cyclopropyl sulfoximine and that was developed to treat patients with untreated small cell lung cancer [6][9]. Aryl cyclopropyl sulfides 1 are also remarkable synthons in organic synthesis (Scheme 1

Aqueous olefin metathesis: recent developments and applications

• Valerio Sabatino and
• Thomas R. Ward

Beilstein J. Org. Chem. 2019, 15, 445–468, doi:10.3762/bjoc.15.39

• . Remakably, no conversion was observed in the absence of MgCl2, which prevents the non-productive binding of the amino acid side chains to ruthenium. The authors suggested that the positive effect of allyl sulfides may be due to the coordination of the sulfur atom to the ruthenium center, favoring the

• formation of the metallacyclobutane intermediate. The modest activities of butenyl and pentenyl sulfides were rationalized by the formation of five and six-membered ring chelates. The aqueous CM with allyl sulfides was also exploited by Hunter et al. for the generation of a metathesis-based dynamic

Metal-free C–H mercaptalization of benzothiazoles and benzoxazoles using 1,3-propanedithiol as thiol source

• Yan Xiao,
• Bing Jing,
• Xiaoxia Liu,
• Hongyu Xue and
• Yajun Liu

Beilstein J. Org. Chem. 2019, 15, 279–284, doi:10.3762/bjoc.15.24

• -catalyzed C–H thiolation of benzothiazole or benzoxazole with a disulfide and a thiol provides easy access to the corresponding sulfides [26][27][28][29][30][31][32][33][34]. However, the examples using C–H functionalization for preparing 2-mercaptobenzoxazoles or 2-mercaptobenzothiazoles are still rare. In

• pathway is proposed (Scheme 3). Initially, 1,3-propanedithiol is possibly oxidized to disulfides 4 and 5 by DMSO. We failed to isolate and determinate these two sulfides, possibly because they are very active in the following coupling reactions. Both disulfides coupled with 1a to give the same C–S

Unprecedented nucleophile-promoted 1,7-S or Se shift reactions under Pummerer reaction conditions of 4-alkenyl-3-sulfinylmethylpyrroles

• Takashi Go,
• Akane Morimatsu,
• Hiroaki Wasada,
• Genzoh Tanabe,
• Osamu Muraoka,
• Yoshiharu Sawada and
• Mitsuhiro Yoshimatsu

Beilstein J. Org. Chem. 2018, 14, 2722–2729, doi:10.3762/bjoc.14.250

• cyclisation reactions. Results and Discussion We prepared sulfoxides as substrates for the Pummerer reactions according to the aforementioned method [32][33]; subsequently, oxidation with mCPBA was performed (Scheme 2). Both the allylic sulfides 4a–f and their sulfoxides 5a–f were obtained in good to high

Synthesis of aryl sulfides via radical–radical cross coupling of electron-rich arenes using visible light photoredox catalysis

• Amrita Das,
• Mitasree Maity,
• Simon Malcherek,
• Burkhard König and
• Julia Rehbein

Beilstein J. Org. Chem. 2018, 14, 2520–2528, doi:10.3762/bjoc.14.228

• triflates [8], and diazonium salts [9]. Typical metals used are palladium [10][11][12][13], copper [14][15][16][17][18][19][20][21], nickel [22][23][24], iron [25][26][27][28][29], cobalt [30][31][32], and rhodium [33][34]. Aryl sulfides are also synthesized by cross coupling of thiols and aryl Grignard

• to the desired product 7. Conclusion In conclusion, we have developed a photocatalytic method for the synthesis of aryl sulfides via a radical–radical cation cross coupling of electron rich arenes with aryl and alkyl disulfides. The reaction proceeds at room temperature and avoids the use of

An amine protecting group deprotectable under nearly neutral oxidative conditions

• Shahien Shahsavari,
• Chase McNamara,
• Mark Sylvester,
• Emily Bromley,
• Savannah Joslin,
• Bao-Yuan Lu and
• Shiyue Fang

Beilstein J. Org. Chem. 2018, 14, 1750–1757, doi:10.3762/bjoc.14.149

• conditions is not feasible. In theory, using the one pot approach, once the sulfides in dM-Dmoc were oxidized, β-elimination would follow to give the desired amine products directly. We tested the idea, and as expected, complex mixtures were formed. Reasons for the observation include oxidation of amine

• products by sodium periodate and its reduced products. In addition, we also found that oxidation of sulfides by sodium periodate was significantly slower under basic conditions than under neutral and acidic conditions. To demonstrate the feasibility of selective deprotection of dM-Dmoc protected amines in

β-Hydroxy sulfides and their syntheses

• Mokgethwa B. Marakalala,
• Edwin M. Mmutlane and
• Henok H. Kinfe

Beilstein J. Org. Chem. 2018, 14, 1668–1692, doi:10.3762/bjoc.14.143

• , hemithioacetal, various thioesters, thiocarbamate and isothiocyanate. This review article focuses on β-hydroxy sulfides and analogs; their presence in natural products, general protocols for their synthesis, and examples of their application in target oriented synthesis. Keywords: alkene thiofunctionalization

• ; epoxide thiolysis; β-hydroxy sulfides; sulfur-containing natural products; Review 1. Introduction Organosulfur compounds are widely distributed in nature, with marine organisms being the richest sources of these, since sulfur, as the sulfate ion, is the second most abundant anion in sea water after

• fascinating biosynthesis of sulfur-containing secondary metabolites can be found in a recent review by Hertweck and co-workers [9]. 2. β-Hydroxy sulfides β-Hydroxy sulfides, often in disguised form, comprise a significant segment of sulfur-containing natural products, with a few examples shown in Figure 2

A survey of chiral hypervalent iodine reagents in asymmetric synthesis

• Soumen Ghosh,
• Suman Pradhan and
• Indranil Chatterjee

Beilstein J. Org. Chem. 2018, 14, 1244–1262, doi:10.3762/bjoc.14.107

• . Review Asymmetric oxidation of sulfides Pribam was the first to use chiral iodine reagents [23]. After a long time without further developments in this direction, Imamoto et al. introduced a new class of chiral hypervalent iodine reagents 1 obtained by the reaction of iodosylbenzene with various

• derivatives of L-tartaric acid anhydrides in 1986. A promising asymmetric induction was achieved for the oxidation of sulfides 23 to sulfoxides 24. This marked the beginning of an era of asymmetric oxidation of sulfides. However, the presence of C2 symmetry in the chiral unit is essential to obtain decent

• enantioselectivity [24]. Later, Kita et al. used chiral tartaric acid derivatives to synthesize chiral I(V) reagents 2 from PhIO2. This represented the first example of the catalytic use of chiral hypervalent reagents in the oxidation of sulfides to sulfoxides with decent enantioselectivities (ees, Scheme 2a). The

Stepwise radical cation Diels–Alder reaction via multiple pathways

• Ryo Shimizu,
• Yohei Okada and
• Kazuhiro Chiba

Beilstein J. Org. Chem. 2018, 14, 704–708, doi:10.3762/bjoc.14.59

• Diels–Alder reaction have employed styrenes, the scope is not limited to such electron-rich dienophiles. Bauld and Yoon demonstrated that aryl vinyl ethers, enol ether equivalents, and aryl vinyl sulfides are also promising dienophiles for the reactions (Scheme 2) [17][20][21][22][23][24][25]. We have

• development in our laboratory. GC–MS Monitoring of the oxidative SET-triggered reaction of aryl vinyl ether 1c. Radical cation Diels–Alder reaction of trans-anethole [17]. Radical cation Diels–Alder reactions of aryl vinyl ether and sulfides [17][25]. Radical cation Diels–Alder reaction of aryl vinyl ether (1

The selective electrochemical fluorination of S-alkyl benzothioate and its derivatives

• Shunsuke Kuribayashi,
• Tomoyuki Kurioka,
• Shinsuke Inagi,
• Ho-Jung Lu,
• Biing-Jiun Uang and
• Toshio Fuchigami

Beilstein J. Org. Chem. 2018, 14, 389–396, doi:10.3762/bjoc.14.27

• fluorination of sulfides having various EWGs at their α-position using Et3N·3HF [9][10]. Since then, we have systematically studied the electrochemical fluorination of numerous organic compounds, heterocycles, and macromolecules by using various fluoride salts such as Et3N·nHF (n = 3–5) and Et4NF·nHF (n = 3–5

• ) [11][12][13][14][15][16][17][18][19]. On the other hand, Simonet and co-workers reported the anodic fluorination of alkyl phenyl sulfides having an EWG on the phenyl group in Et3N·3HF/MeCN to provide α-monofluorinated products in moderate yields [20]. We also achieved the anodic fluorination of benzyl

Photocatalytic formation of carbon–sulfur bonds

• Alexander Wimmer and
• Burkhard König

Beilstein J. Org. Chem. 2018, 14, 54–83, doi:10.3762/bjoc.14.4

• disulfide, thioamide derivatives and sulfides Disulfides and thiosulfates Sulfoxides Sulfinic acids, sulfinate salts and sulfinamides Sulfonyl halides, sulfonyl hydrazines, thionyl chloride and sulfur dioxide C–S bond formations initiated by irradiation with light of wavelengths shorter than 380 nm or by

• radical initiators as well as photocatalytic reactions, where sulfur-containing substrates act as a sacrificial agent are not discussed in this review [23][24][25][26][27][28]. Review Thiols Formation of sulfides and sulfoxides A large number of photocatalytic C–S bond-forming methods report the

• preparation of sulfides. Non-photocatalytic procedures apply the so-called radical thiol–ene or radical thiol–yne reactions for efficient cross-coupling of thiols with olefins [24][29][30]. In 2013, Yoon and co-workers developed a photoredox-catalyzed version of the radical thiol–ene reaction (Scheme 2) [31

Ni nanoparticles on RGO as reusable heterogeneous catalyst: effect of Ni particle size and intermediate composite structures in C–S cross-coupling reaction

• Debasish Sengupta,
• Koushik Bhowmik,
• Goutam De and
• Basudeb Basu

Beilstein J. Org. Chem. 2017, 13, 1796–1806, doi:10.3762/bjoc.13.174

• iodoarenes and arylthiols bearing different groups like Me, OMe, F, COCH3, NO2 are equally efficient to undergo cross-coupling reactions producing the corresponding unsymmetrical diaryl sulfides 3a–i in 88–93% isolated yields (Table 2, entries 1–9). No significant influence of electron-donating or electron

Urea–hydrogen peroxide prompted the selective and controlled oxidation of thioglycosides into sulfoxides and sulfones

• Adesh Kumar Singh,
• Varsha Tiwari,
• Kunj Bihari Mishra,
• Surabhi Gupta and
• Jeyakumar Kandasamy

Beilstein J. Org. Chem. 2017, 13, 1139–1144, doi:10.3762/bjoc.13.113

• , oxidation susceptible olefin functional groups were found to be stable during the oxidation of sulfide. Keywords: monosaccharides; oxidation; sulfones; sulfoxides; thioglycosides; urea–hydrogen peroxide; Introduction Organosulfur compounds such as sulfides, sulfoxides and sulfones are useful intermediates

• , glycosyl sulfones are known to be potential glycosyltransferase inhibitors [13]. Glycosyl sulfoxides and sulfones are prepared from the corresponding sulfides using various oxidizing reagents [5][6][7][10]. Although a number of oxidation methods were developed for the oxidation of simple organic sulfides

• , intolerance of other oxidation susceptible functional groups, etc. Thus, developing a mild and efficient method for the controlled oxidation of sulfides to corresponding glycosyl sulfoxides and sulfones, is of great interest. The utility of hydrogen peroxide–solid adducts in organic synthesis is well explored

Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes

• Carmen Moreno-Marrodan,
• Francesca Liguori and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2017, 13, 734–754, doi:10.3762/bjoc.13.73

• more usual strategy is the so-called “selective poisoning”, i.e., the improvement of the catalyst’s selectivity by the addition of variable, often large, amount of contaminants, either organic ligands (quinolone [65][66], phosphine [67]), carbon monoxide [68], sulfides [69], sulfoxides [70][71] defined

Conjecture and hypothesis: The importance of reality checks

• David Deamer

Beilstein J. Org. Chem. 2017, 13, 620–624, doi:10.3762/bjoc.13.60

• universal common ancestor (LUCA) may have originated in hydrothermal vents. The iron-sulfur chemistry proposed for hydrothermal vents was tested by Huber and Wächtershäuser [15][16] who simulated vent conditions with boiling mixtures of iron and nickel sulfides to which various reactants were added. They

Transition-metal-catalyzed synthesis of phenols and aryl thiols

• Yajun Liu,
• Shasha Liu and
• Yan Xiao

Beilstein J. Org. Chem. 2017, 13, 589–611, doi:10.3762/bjoc.13.58

• , amide, bromo and trifluoromethyl were tolerated in this process. They also showed the application of the developed protocol in the synthesis of aryl alkyl sulfides via a “one-pot reaction”. In 2011, the Xu and Feng group applied CuI-nanoparticles to synthesize aryl thiols through a coupling reaction of

Fast and efficient synthesis of microporous polymer nanomembranes via light-induced click reaction

• Qi An,
• Youssef Hassan,
• Xiaotong Yan,
• Peter Krolla-Sidenstein,
• Tawheed Mohammed,
• Mathias Lang,
• Stefan Bräse and
• Manuel Tsotsalas

Beilstein J. Org. Chem. 2017, 13, 558–563, doi:10.3762/bjoc.13.54

• radicals. Additional thiol moieties can undergo hydrogen transfer to the vinyl radical leading to thiyl radicals and vinyl sulfides. The vinyl sulfides can then undergo a thiol–ene coupling (TEC) reaction, leading to bis-sulfide species. TYC has been used for surface modification [21][22

Ionic liquids as transesterification catalysts: applications for the synthesis of linear and cyclic organic carbonates

• Maurizio Selva,
• Alvise Perosa,
• Sandro Guidi and
• Lisa Cattelan

Beilstein J. Org. Chem. 2016, 12, 1911–1924, doi:10.3762/bjoc.12.181

• protonation or quaternization of neutral precursors (imidazoles, amines, phosphines, pyridine or sulfides) with Brønsted acids or haloalkanes/dialkylsulfates, respectively. In the next step, a variety of ionic liquids are obtainable by anion exchange, either through direct treatments with Lewis acids or by

The aminoindanol core as a key scaffold in bifunctional organocatalysts

• Isaac G. Sonsona,
• Eugenia Marqués-López and
• Raquel P. Herrera

Beilstein J. Org. Chem. 2016, 12, 505–523, doi:10.3762/bjoc.12.50

• disulfides and sulfides, which are involved in the synthesis of ligands and pharmaceutical chiral synthetic precursors [1][2] and in (b) the transfer-hydrogenation reaction catalyzed by bifunctional chiral ruthenium complexes, employed in the synthesis of peptide mimics with an interesting