Progress in the total synthesis of inthomycins

• Bidyut Kumar Senapati

Beilstein J. Org. Chem. 2021, 17, 58–82, doi:10.3762/bjoc.17.7

• TMS group of 126 was found to be extremely challenging. The commonly used conditions provided the allene as a major product instead of the desired product. Ultimately, the mono-desilylated product 127 was obtained in 85% yield by using sodium sulfide in a mixture of THF and water. Next, the zirconium

Synthetic approaches to bowl-shaped π-conjugated sumanene and its congeners

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 2212–2259, doi:10.3762/bjoc.16.186

• assessable 1,2,3,4,5,6-hexakis(bromomethyl)benzene (142) to generate benzotrithiophene 143 using sodium sulfide followed by DDQ oxidation. Having benzotrithiophene 143 in hand, it was then subjected to bromination using NBS in DMF to produce two isomeric tribromo derivatives 144 and 145 which were

Selective preparation of tetrasubstituted fluoroalkenes by fluorine-directed oxetane ring-opening reactions

• Clément Q. Fontenelle,
• Thibault Thierry,
• Romain Laporte,
• Emmanuel Pfund and
• Thierry Lequeux

Beilstein J. Org. Chem. 2020, 16, 1936–1946, doi:10.3762/bjoc.16.160

• unsuccessful reduction of the corresponding ethyl ester (vide infra, 12). Then we turned our attention to the modified Julia reaction since the reduction of the ester functionality could be achieved at the sulfide stage [29], prior to its oxidation to give 6. Alcohol 6 was not stable in basic medium, as a

Synthesis, docking study and biological evaluation of ᴅ-fructofuranosyl and ᴅ-tagatofuranosyl sulfones as potential inhibitors of the mycobacterial galactan synthesis targeting the galactofuranosyltransferase GlfT2

• Marek Baráth,
• Jana Jakubčinová,
• Zuzana Konyariková,
• Stanislav Kozmon,
• Katarína Mikušová and
• Maroš Bella

Beilstein J. Org. Chem. 2020, 16, 1853–1862, doi:10.3762/bjoc.16.152

• -chloroperbenzoic acid (m-CPBA, 12 equiv) led to the simultaneous phosphorylation of the hydroxy group and to the oxidation of the sulfide to give 1-O-dibenzyloxyphosphoryl-ᴅ-fructofuranosyl sulfones 7α, 8α, 8β and 9α in excellent yields (Scheme 1). Final removal of benzyl protecting groups by catalytic

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

• amine/base with DMSO as an activator. Potassium ethylxanthate [64][65] and sodium sulfide as a sulfur sources in the presence of Et3N in DMSO (Table 1, entries 8 and 9) also did not furnish the desired product 2bA. A decomposition of the product was observed in the case of Na2S. Interestingly, 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

• synthesize trifluoromethylated nitrogen- and sulfur-based bicyclic compounds (Scheme 13) [53]. Using this methodology, the corresponding cyclopentenones 29 were isolated in generally good yields, except for sulfur-containing derivative 29c, due to the oxidation of the sulfide under the reaction conditions

• diastereoselectivity [57][58]. In this work, Si−O tethered 1,7-enynes underwent the PKR after treatment with 1.05 equiv of Co2(CO)8 using 4-fluorobenzyl(methyl)sulfide (4-FBnSMe) as an additive, which is commercially available and can be easily recovered by flash chromatography. Under the aforementioned conditions

One-pot synthesis of 1,3,5-triazine-2,4-dithione derivatives via three-component reactions

• Gui-Feng Kang and
• Gang Zhang

Beilstein J. Org. Chem. 2020, 16, 1447–1455, doi:10.3762/bjoc.16.120

• method, triazinethione derivatives were synthesized through the sulfidation of triazine using phosphorus oxychloride and hydrogen sulfide (Scheme 1c) [18]. This strategy required harsh reaction conditions and also suffered from an awful smell. Therefore, the development of facile and environmentally

Recent synthesis of thietanes

• Jiaxi Xu

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

• , or disulfonates of alkane-1,3-diols with sodium sulfide. The intramolecular substitution of 3-mercaptoalkyl halides or sulfonates is a similar strategy for the preparation of thietanes [12][13][14]. Alternatively, inter- and intramolecular photochemical [2 + 2] cycloadditions (thia-Paternò–Büchi

• double nucleophilic displacements 2.1.1 Synthesis via double nucleophilic displacements of 1,3-dihaloalkanes: Although the double nucleophilic displacements of 1,3-dihaloalkanes with sodium sulfide are the oldest methods for the preparation of thietane derivatives and have well been studied, they are

• double displacement with sodium sulfide to obtain thietane-3,3-diyldimethanol (13), which was further converted into two different thietanose nucleosides 2 and 14 [33] (Scheme 2). In the synthesis of sesquiterpene thioalkaloids, the method also was utilized. A double-aldol condensation of methyl

Development of fluorinated benzils and bisbenzils as room-temperature phosphorescent molecules

• Shigeyuki Yamada,
• Takuya Higashida,
• Yizhou Wang,
• Masato Morita,
• Takuya Hosokai,
• Kaveendra Maduwantha,
• Kaveenga Rasika Koswattage and
• Tsutomu Konno

Beilstein J. Org. Chem. 2020, 16, 1154–1162, doi:10.3762/bjoc.16.102

• oxygen atom in DMSO to construct a cationic vinylpalladium(II) species (Int-B). Further nucleophilic attack of another DMSO molecule against Int-B, followed by elimination of dimethyl sulfide, furnishes a cationic intermediate (Int-C). Finally, immediate elimination of dimethyl sulfide and the Pd(II

Recent applications of porphyrins as photocatalysts in organic synthesis: batch and continuous flow approaches

• Rodrigo Costa e Silva,
• Luely Oliveira da Silva,
• Aloisio de Andrade Bartolomeu,
• Timothy John Brocksom and
• Kleber Thiago de Oliveira

Beilstein J. Org. Chem. 2020, 16, 917–955, doi:10.3762/bjoc.16.83

• medicine and pharmacology [94], justifying many studies on this topic. The accepted mechanism for sulfide oxidation to sulfoxide involves the chemical quenching of singlet oxygen by sulfur compounds which leads to the persulfoxide intermediate. From this intermediate, a variety of reaction pathways are

• suggested to give the oxidized product, including the quenching with a second molecule of sulfide (Scheme 44) [67][95][96]. Recent advances have also been achieved using photostable porphyrins and/or heterogeneous catalysts. Mojarrad and Zakavi reported that the oxidation of sulfides using diprotonated

Regio- and stereoselective synthesis of new ensembles of diversely functionalized 1,3-thiaselenol-2-ylmethyl selenides by a double rearrangement reaction

• Svetlana V. Amosova,
• Andrey A. Filippov,
• Nataliya A. Makhaeva,
• Alexander I. Albanov and
• Vladimir A. Potapov

Beilstein J. Org. Chem. 2020, 16, 515–523, doi:10.3762/bjoc.16.47

• exhibits unusual properties in nucleophilic reactions. This reagent was obtained [30][31][32] in high yield and with high purity by a one-pot synthesis from divinyl sulfide [33][34][35] and selenium dibromide. The structure of compound 1 suggests the possibility of formation of both seleniranium 2 and

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

• ]. Thus, the diphosphine ligand 51 was obtained in good yield by reacting 2,6-bis(chloromethyl)pyridine (50) with phosphine lithiothiolate 49. The latter was obtained by treatment of diphenylphosphine (48) with n-BuLi and ethylene sulfide in tetrahydrofuran at very low temperatures. Metal–proton exchange

• and mono-N-methylated spiro 1,3-amino alcohols 124. The mixture was equilibrated under reflux allowing P-center inversion and an uneven mixture of diastereoisomers 125 and 127 was obtained. Treating the mixture with borane·dimethyl sulfide gave a mixture of diastereoisomers in a ratio of 2:5. The

The reaction of arylmethyl isocyanides and arylmethylamines with xanthate esters: a facile and unexpected synthesis of carbamothioates

• Narasimhamurthy Rajeev,
• Toreshettahally R. Swaroop,
• Ahmad I. Alrawashdeh,
• Shofiur Rahman,
• Abdullah Alodhayb,
• Seegehalli M. Anil,
• Kuppalli R. Kiran,
• Chandra,
• Paris E. Georghiou,
• Kanchugarakoppal S. Rangappa and
• Maralinganadoddi P. Sadashiva

Beilstein J. Org. Chem. 2020, 16, 159–167, doi:10.3762/bjoc.16.18

• [7], insecticides (cartap) [8], and herbicides [9]. They are also used as key intermediates in the generation of carbonyl sulfide/hydrogen sulfide [10], the synthesis of isothiocyanates [11], asymmetric thioureas [12], and thiazolidine/thiaoxazine [13]. Therefore, as a result, numerous synthetic

Convenient synthesis of the pentasaccharide repeating unit corresponding to the cell wall O-antigen of Escherichia albertii O4

• Tapasi Manna,
• Arin Gucchait and
• Anup Kumar Misra

Beilstein J. Org. Chem. 2020, 16, 106–110, doi:10.3762/bjoc.16.12

• formation [signals at δ 5.26 (d, J = 1.5 Hz, H-1D), 4.23 (d, J = 9.5 Hz, H-1C) in 1H NMR and at δ 98.4 (C-1D), 84.8 (C-1C) in 13C NMR spectra] (Scheme 2). It is worth noting that sulfide linkage at the anomeric position of compound 4 remained unaffected under the reaction conditions. Having achieved the

[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

• set of substrates 6–25 was prepared from dimethylphenylphosphine sulfide 4 (Table 1). All compounds were obtained in good yields, both from aldehydes and ketones. For aldehydes and unsymmetrically substituted ketones, the formation of the products as diastereomeric mixtures could be observed

• . Interestingly, compound 18 underwent isobutene elimination rather than rearrangement under the reaction conditions, whereas compound 19 led to the formation of a mixture of three products, with alkenylphosphine sulfide 35 being the major compound. The structures were assigned based on NMR analysis as all

• compounds failed to give single crystals for X-ray analysis. The presence of an oxygen atom attached to the phosphorus atom in the products could be deduced based on 1H and 13C NMR analysis. In the 1H NMR spectra of phosphine sulfide 12, the chemical shifts of the signals belonging to the aromatic protons

Starazo triple switches – synthesis of unsymmetrical 1,3,5-tris(arylazo)benzenes

• Andreas H. Heindl and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2020, 16, 22–31, doi:10.3762/bjoc.16.4

• using an aqueous ammonium sulfide solution to furnish aniline 6 in 65% yield [20]. After oxidation of 6 to its nitroso analogue 7 [21], a Baeyer–Mills reaction with aniline yielded the targeted azobenzene building block 8 in 87% yield (i.e., 53% yield over four steps). After the successful synthesis of

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

• 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

Synthesis of novel sulfide-based cyclic peptidomimetic analogues to solonamides

• José Brango-Vanegas,
• Luan A. Martinho,
• Lucinda J. Bessa,
• Andreanne G. Vasconcelos,
• Alexandra Plácido,
• Alex L. Pereira,
• José R. S. A. Leite and
• Angelo H. L. Machado

Beilstein J. Org. Chem. 2019, 15, 2544–2551, doi:10.3762/bjoc.15.247

• , 420013, Porto, Portugal Bioprospectum, Lda, UPTEC, 4200135, Porto, Portugal Campus de Ceilândia, Universidade de Brasília, Centro Metropolitano, 72220-275, Ceilândia Sul, Ceilândia, DF, Brazil 10.3762/bjoc.15.247 Abstract Eight new sulfide-based cyclic peptidomimetic analogues of solonamides A and B

• structurally related to these natural peptidomimetics has been used as a promising strategy for the attenuation of bacterial virulence in strains of S. aureus [12][13][14][15]. Herein, we report the synthesis of new sulfide-based cyclic peptidomimetics through the allylic nucleophilic substitution (SN2’) of

• was based on the conservation of the 16-membered macrocyclic scaffold and the apolar tripeptidyl moiety found in the solonamides. Both features are important to guarantee the interference with S. aureus QS [12][13][14][15]. The ester linkage of the lactone core was substituted by the sulfide group

Chiral terpene auxiliaries V: Synthesis of new chiral γ-hydroxyphosphine oxides derived from α-pinene

• Anna Kmieciak and
• Marek P. Krzemiński

Beilstein J. Org. Chem. 2019, 15, 2493–2499, doi:10.3762/bjoc.15.242

• (III) chloride in methanol in 88% yield (Scheme 1). The synthesis of allylic alcohol 11, a regioisomer of 6, started again from (1R)-α-pinene (1, Scheme 2). Hydroboration of (1R)-α-pinene with borane–dimethyl sulfide adduct (BMS) and crystallization of the product diisopinocampheylborane (dIpc2BH, 84

• % yield. The allylic diphenylphosphine oxide 21 was subjected to the hydroboration–oxidation reaction introducing stereoselectively the hydroxy group. Hydroboration was carried out with an excess of borane–dimethyl sulfide adduct followed by the oxidation step. The standard C–B bond oxidation protocol

• borane–dimethyl sulfide adduct in THF at 50 ºC. Oxidation of the alkylborane with mCPBA gave the desired alcohol 27 in 51% overall yield. Finally, diastereomeric endocyclic allylic alcohols 16 and 18 were treated with chlorodiphenylphosphine in the presence of DMAP to produce diphenylphosphinites 28 and

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

• hexafluorophosphoric acid (Scheme 1a and 1b) [3][4][9][10], oxidation of thioxanthene in the presence of PbO2 followed by dehydration by tetrafluoroboric acid [1], the reaction of 4,4’-bis(dimethylamino)diphenylmethane with sulfur in the presence of ZnCl2 [11], and the ring-closure reaction of diaryl sulfide in the

• ) sulfide (1a) with benzoyl chloride (2a) in the presence of Brønsted acids in chlorobenzene at several temperatures (Table 1). When we used a strong Brønsted acid such as trifluoromethanesulfonic acid (TfOH) at room temperature, the desired thioxanthylium salt 3a was obtained with 21% yield while other

• sulfide 1 and benzoyl chloride 2 (Figure 1). o-Toluoyl chloride smoothly afforded the desired product 3b in excellent yield. Moreover, the reaction was performed on the 2 mmol scale to furnish the desired product in 73% yield, suggesting that the reaction can be applied to large scale conditions. In

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

• alcohols and asymmetric sulfide oxidation [91]. Diverse reactivity, cost efficiency and variable oxidation state [Ni(0)–Ni(IV)] associated with nickel led to remarkable developments in the field of catalytic applications [68]. Nickel catalysis involved cycloaddition, cyclization, C–H bond functionalization

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

• base, no reaction occurred, and consequenctly the base was necessary for both steps of the thiocarbamate formation. This also explains why two equivalents of base were required. Sodium sulfide as the base provided only traces of 3a suggesting that the activation of sulfur by NaH produces rather a

• polysulfide anion instead of sodium sulfide [74][107][108] (Scheme 7, reaction 3). It caught our attention that only isothiocyanate was generated in the presence of NaOEt (Table 1, entry 20). We suspected that THF might not be the best solvent for this base, hence the reaction was performed in MeCN providing

Selenophene-containing heterotriacenes by a C–Se coupling/cyclization reaction

• Pierre-Olivier Schwartz,
• Sebastian Förtsch,
• Astrid Vogt,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2019, 15, 1379–1393, doi:10.3762/bjoc.15.138

• the synthesis of dithienothiophene 1, which is mostly built up by oxidative dehydrocoupling of 3,3’-dithienyl sulfide or ring-closure reactions of brominated thiophenes with ethyl mercaptoacetate, are described in literature [24]. For comparability to the selenophene-containing triacenes 2–4, we

• reinvestigated the synthesis of DTT 1 by using a Cu-catalyzed C–S cross-coupling reaction with potassium sulfide (K2S) as sulfur source [29]. The best results for this C–S ring-closure reaction were achieved by reacting 3,3’-diiodo-2,2’-bithiophene (5) [30] with the system K2S and copper iodide (CuI) as catalyst

• corresponding dibromobiselenophene and benzene sulfonyl sulfide as sulfur source (50% yield) [27]. In parallel, TMS-protected iodinated biselenophene 11 was subjected to selenourea, copper oxide nanoparticles, and potassium hydroxide in DMSO to isolate diselenolo[3,2-b:2’,3’-d]selenophene (DSS, 4) in 48% yield

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

• cleavage or oxidation of one sulfide in further studies. Conclusion The reported reaction of [1.1.1]propellane with aromatic and to a certain extend aliphatic disulfides provides access to [2]staffanes and symmetrical and unsymmetrical BCPs. The separation of these compounds is often challenging due to the