Isotopically labeled sulfur compounds and synthetic selenium and tellurium analogues to study sulfur metabolism in marine bacteria

• Nelson L. Brock,
• Christian A. Citron,
• Claudia Zell,
• Martine Berger,
• Irene Wagner-Döbler,
• Jörn Petersen,
• Thorsten Brinkhoff,
• Meinhard Simon and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2013, 9, 942–950, doi:10.3762/bjoc.9.108

• , Germany 10.3762/bjoc.9.108 Abstract Members of the marine Roseobacter clade can degrade dimethylsulfoniopropionate (DMSP) via competing pathways releasing either methanethiol (MeSH) or dimethyl sulfide (DMS). Deuterium-labeled [2H6]DMSP and the synthetic DMSP analogue dimethyltelluriopropionate (DMTeP

• ]. DMSP is degraded by marine bacteria either under the formation of methanethiol (MeSH) or of dimethyl sulfide (DMS) with a large impact on both the global sulfur cycle and climate [12][13]. DMSP degradation to MeSH starts with the DmdA mediated demethylation to 3-(methylthio)propionate (Scheme 1A) [14

• second obvious candidate as a source for sulfur volatiles is inorganic sulfate, which can be reduced by Roseobacter clade members to hydrogen sulfide via adenylyl sulfate, 3’-phosphoadenylyl sulfate, and sulfite (Scheme 2) [17]. Hydrogen sulfide enters the amino acid pool by reaction with O-acetyl-L

Utilizing the σ-complex stability for quantifying reactivity in nucleophilic substitution of aromatic fluorides

• Magnus Liljenberg,
• Tore Brinck,
• Tobias Rein and
• Mats Svensson

Beilstein J. Org. Chem. 2013, 9, 791–799, doi:10.3762/bjoc.9.90

• of carbocyclic as well as heterocyclic fluorinated substrates [4][5]. Anionic nucleophiles (anions of methanol, benzyl alcohol and hydrogen sulfide) were investigated, as well as neutral nucleophiles (amines). The accuracy was well within 1 kcal/mol and the predictions can be used in a quantitative

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

• heating of 1d in chlorobenzene at 120 °C for 12 h in 78% yield (Scheme 8). According to mass spectrometry and elemental analysis, this is formally a product of H2S elimination, which was confirmed by isolation of triethylammonium hydrogen sulfide in practically quantitative yield from the reaction mixture

• formation of thiol 17 followed by the dihydropyrrole ring closure under the impact of both quinone and amine groups and the generation of the aromatic pyrrole cycle with hydrogen sulfide extrusion by the action of base (triethylamine). Although, to the best of our knowledge, the transformation of 3H-spiro

Some aspects of radical chemistry in the assembly of complex molecular architectures

• Béatrice Quiclet-Sire and
• Samir Z. Zard

Beilstein J. Org. Chem. 2013, 9, 557–576, doi:10.3762/bjoc.9.61

• fluorine by the sulfide anion thus produced, and loss of a molecule of ethanol. Such, hitherto rare, structures can now be accessed in two easy steps that could in principle be performed in one pot. Variety is readily obtained by merely modifying the alkene or by taking advantage of the presence of the

Efficient Cu-catalyzed base-free C–S coupling under conventional and microwave heating. A simple access to S-heterocycles and sulfides

• Silvia M. Soria-Castro and
• Alicia B. Peñéñory

Beilstein J. Org. Chem. 2013, 9, 467–475, doi:10.3762/bjoc.9.50

• substitution reactions with methyl iodide and benzyl bromide, methyl phenyl sulfide and benzyl methyl sulfide in 81% and 66% yields, respectively, and 4-anisyl phenyl sulfide (4-AnSPh) in 85% yield (quantified by 1H NMR) by a second copper-catalyzed reaction (Scheme 8). Conclusion We have developed a simple

• corresponding alkyl halide (0.75 mmol, 1.5 equiv) or KI/I2 (1.5 mmol/0.51 mmol, 3/1.02 equiv) was then added and stirred for 20 min or 24 h, respectively. The work-up of the reactions was similar to that of Method A. For the synthesis of the asymmetric diaryl sulfide, after hydrolysis of the thioester, a second

New simple synthesis of ring-fused 4-alkyl-4H-3,1-benzothiazine-2-thiones: Direct formation from carbon disulfide and (E)-3-(2-aminoaryl)acrylates or (E)-3-(2-aminoaryl)acrylonitriles

• Qiuping Ding,
• Yuqing Lin,
• Guangni Ding,
• Fumin Liao,
• Xiaoyan Sang and
• Yi-Yuan Peng

Beilstein J. Org. Chem. 2013, 9, 460–466, doi:10.3762/bjoc.9.49

• -isothiocyanatophenyl)prop-2-enoates with sodium sulfide, this method suffers from the tedious synthesis of the substrates prepared in four steps from 2-iodoaniline [16]. Molina et al. also described the preparation of 4H-3,1-benzothiazine-2-thione derivatives by intramolecular heteroconjugate addition of carbodiimides

A new synthetic protocol for coumarin amino acid

• Xinyi Xu,
• Xiaosong Hu and
• Jiangyun Wang

Beilstein J. Org. Chem. 2013, 9, 254–259, doi:10.3762/bjoc.9.30

• coumarinylacetic acid, which was then reduced to an alcohol by borane-dimethyl sulfide. After the phenolic hydroxy group was protected with a tert-butyl(dimethyl)silyl group, the alcohol was converted into a bromide and was used to alkylate a glycine enolate synthon to afford an imine. All the protecting groups

Flow photochemistry: Old light through new windows

• Jonathan P. Knowles,
• Luke D. Elliott and
• Kevin I. Booker-Milburn

Beilstein J. Org. Chem. 2012, 8, 2025–2052, doi:10.3762/bjoc.8.229

• by Aggarwal et al. to scale up the photochemical generation of a thioaldehyde 85 (Scheme 28) [81]. The in situ generated species underwent spontaneous Diels–Alder cycloaddition in the presence of cyclopentadiene. The reaction was performed on 18.2 g (60 mmol) of phenacyl sulfide 84 under batch

• conditions in neat cyclopentadiene to give a 65% yield after 9 hours. Under optimised flow conditions 38 g (126 mmol) of the sulfide was irradiated in DCM (0.2 M) in the presence of 40 equiv cyclopentadiene at 2 mL/min (5.25 hours in total) to give a 75% yield of 86. One issue with photochemical flow

The chemistry of bisallenes

• Henning Hopf and
• Georgios Markopoulos

Beilstein J. Org. Chem. 2012, 8, 1936–1998, doi:10.3762/bjoc.8.225

Metal–ligand multiple bonds as frustrated Lewis pairs for C–H functionalization

• Matthew T. Whited

Beilstein J. Org. Chem. 2012, 8, 1554–1563, doi:10.3762/bjoc.8.177

• were observed when carbon dioxide, carbonyl sulfide, and isocyanates were utilized, cleanly generating the Ir(I) carbonyl as a byproduct (Scheme 11) [71]. The nucleophilicity of the iridium center was demonstrated through a series of experiments. First, it was noted that the carbene complex does not

Influence of cyclodextrin on the solubility of a classically prepared 2-vinylcyclopropane macromonomer in aqueous solution

• Helmut Ritter,
• Jia Cheng and
• Monir Tabatabai

Beilstein J. Org. Chem. 2012, 8, 1528–1535, doi:10.3762/bjoc.8.173

• is flushed with nitrogen until it is colorless. Then, 4 mL of dimethyl sulfide (DMS) are added to the solution. The reaction mixture is stirred overnight at rt. Methanol is removed under reduced pressure. Mn = 1.8 × 104 g/mol, DI = 2.2; dn = 5.2 nm. MALDI-TOF MS of amino-terminated poly(NiPAAm) 3

Stereoselective synthesis of trans-fused iridoid lactones and their identification in the parasitoid wasp Alloxysta victrix, Part I: Dihydronepetalactones

• Nicole Zimmermann,
• Robert Hilgraf,
• Lutz Lehmann,
• Daniel Ibarra and
• Wittko Francke

Beilstein J. Org. Chem. 2012, 8, 1246–1255, doi:10.3762/bjoc.8.140

• the key intermediate 16 – which shows two differentiated primary alcohol functions – started from enantiomerically pure (R)-limonene (14, Scheme 2). Ozonolysis followed by reductive workup with dimethyl sulfide produced (3R)-3-(1-methylethenyl-6-oxoheptanal), which yielded the formyl cyclopentene 15

Algicidal lactones from the marine Roseobacter clade bacterium Ruegeria pomeroyi

• Ramona Riclea,
• Julia Gleitzmann,
• Hilke Bruns,
• Corina Junker,
• Barbara Schulz and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2012, 8, 941–950, doi:10.3762/bjoc.8.106

• dissolved DMSP available for bacterial degradation to methanethiol (MeSH) [10] or dimethyl sulfide (DMS) [11][12][13][14][15]. The bacterial production of DMS is important for the global sulfur cycle [16][17] and the planet’s climate [18][19], while the alternative DMSP degradation product MeSH controls the

Synthesis and characterization of a novel carboxyl group containing (co)polyimide with sulfur in the polymer backbone

• Miroslav Mrsevic,
• David Düsselberg and
• Claudia Staudt

Beilstein J. Org. Chem. 2012, 8, 776–786, doi:10.3762/bjoc.8.88

• ) sulfide (4,4′-diaminodiphenyl sulfide, 4,4′-SDA) groups, were used for the synthesis of novel (co)polyimides in this work [25]. In order to investigate structural effects of the DABA groups on the glass-transition temperature, molecular weight, transparency and water sorption, both polymers 6FDA-4,4′-SDA

• to determine the average of the molecular weight (). Table 2 shows the of the synthesized (co)polyimides determined by UV detection. The synthesized (co)polyimides showed average molecular weights between 26,000 and 77,000 g·mol−1. The molecular weights of the sulfide-containing (co)polyimides

• -mentioned behavior. Apparently, the sulfide-containing (co)polyimides exhibit higher Tg values than the sulfone-containing (co)polyimides. This is due to the differently substituted aromatic diamines. The para-substituted 4,4′-SDA induces a higher stiffness compared to the meta-substituted 3,3′-DDS, which

Valence isomerization of cyclohepta-1,3,5-triene and its heteroelement analogues

• Helen Jansen,
• J. Chris Slootweg and
• Koop Lammertsma

Beilstein J. Org. Chem. 2011, 7, 1713–1721, doi:10.3762/bjoc.7.201

• ]. Thiepine – benzene sulfide The parent thiepine (5) is 7.0 kcal·mol−1 less stable than benzene sulfide (6). This energy difference is much larger than for the oxygen homologues, because three-membered rings accommodate sulfur better than oxygen [40]. Nonetheless, bicyclic 6 has never been isolated, probably

Novel fatty acid methyl esters from the actinomycete Micromonospora aurantiaca

• Jeroen S. Dickschat,
• Hilke Bruns and
• Ramona Riclea

Beilstein J. Org. Chem. 2011, 7, 1697–1712, doi:10.3762/bjoc.7.200

• , dimethyl sulfide, and 4-dimethylaminopyridine gave methyl 5-methylheptanoate (118b). A sequence of LiAlH4 reduction to the alcohol 119b, conversion into the bromide 120b, and Cu-mediated 1,4-addition of the Grignard reagent to methyl acrylate furnished the desired FAME 95. Its mass spectrum and retention

Synthesis and oxidation of some azole-containing thioethers

• Andrei S. Potapov,
• Nina P. Chernova,
• Vladimir D. Ogorodnikov,
• Tatiana V. Petrenko and
• Andrei I. Khlebnikov

Beilstein J. Org. Chem. 2011, 7, 1526–1532, doi:10.3762/bjoc.7.179

• -(2-chloroethyl)-3,5-dimethylpyrazole hydrochloride with sodium sulfide in 50% aqueous ethanol. The product was obtained in the form of an oil, even after purification by flash chromatography [11]. Haanstra et al. used the tosyloxy derivative instead of the chloro derivative in the reaction with

• sodium sulfide. The thioether was isolated as a crystalline powder, but it was used without purification as a ligand for complex preparation, so no analytical data was reported, except for the 1H NMR spectrum [12]. Ros et al. proposed an alternative synthetic route starting from 1-(2-mercaptoethyl)-3,5

Pseudo five-component synthesis of 2,5-di(hetero)arylthiophenes via a one-pot Sonogashira–Glaser cyclization sequence

• Dominik Urselmann,
• Dragutin Antovic and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2011, 7, 1499–1503, doi:10.3762/bjoc.7.174

• Sonogashira–Glaser cyclization sequence. Results and Discussion The conversion of 1,4-diaryl-1,3-butadiynes into 2,5-diarylthiophenes by base-mediated cyclization with sodium sulfide or sodium hydrogen sulfide is a literature-known procedure [16][17][18][19][20][21][22][23]. Therefore, we reasoned that the

• concatenation of our sequentially Pd/Cu-catalyzed Sonogashira–Glaser reaction [15] with the sulfide-mediated cyclization should lead to a straightforward one-pot pseudo five-component synthesis of 2,5-di(hetero)arylthiophenes (Scheme 2). We first set out to identify an optimal cosolvent for all four steps

• symmetrical 2,5-di(hetero)arylthiophenes based upon an initial sequentially Pd/Cu-catalyzed Sonogashira–Glaser process followed by a subsequent sulfide-mediated cyclization. A broad range of functional groups is tolerated and the iodo substrates are either commercially available or easily accessible. This

The Eschenmoser coupling reaction under continuous-flow conditions

• Sukhdeep Singh,
• J. Michael Köhler,
• Andreas Schober and
• G. Alexander Groß

Beilstein J. Org. Chem. 2011, 7, 1164–1172, doi:10.3762/bjoc.7.135

• desired Eschenmoser coupling products were obtained within 70 s residence time. The reaction kinetics was investigated and 15 examples of different building block combinations are given. Keywords: activation energy; episulfide; flow chemistry; keto imine; kinetics; S-alkylation; sulfide contraction

• ; triisopropyl phosphite; Introduction The Eschenmoser coupling [1][2] is a reaction method that yields β-enaminocarbonyl derivatives of type 4 by the elimination of sulfur (sulfide contraction) from an episulfide intermediate (Scheme 1). The reaction was described for the first time by Knott in 1955 [3] and

• - [5], sedamine alkaloid- [6], sparteine- [7], mersicarpine- [8], batzelladine- [9], fuligocandin- [10] and vitamin B12-derivatives [11] were prepared with the aid of sulfide contraction steps. Pharmaceutically important substances, such as methylphenidat [12] or the marine neurotoxin hemibrevetoxin

Nano copper oxide catalyzed synthesis of symmetrical diaryl sulfides under ligand free conditions

• K. Harsha Vardhan Reddy,
• V. Prakash Reddy,
• A. Ashwan Kumar,
• G. Kranthi and
• Y.V.D. Nageswar

Beilstein J. Org. Chem. 2011, 7, 886–891, doi:10.3762/bjoc.7.101

• decrease in the yield of the diaryl sulfide (Table 3, entries 12 and 13) was observed. Under these reaction conditions, various hetero aromatic iodides were reacted with potassium thiocyanate and gave the corresponding diaryl sulfides in appreciable yields (Table 3, entries 15, 16 and 17). In case of the

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

• epoxide ring opening of 18 with potassium hydrogen sulfide (Scheme 7) [18]. Epoxide ring opening by a sulfur nucleophile was also employed as the key step in the synthesis of (+)-BE-52440A (22) [22] (Scheme 8). Dimerisation of nanaomycin derivative 21 through a bridging sulfide involves a double

The preparation of 3-substituted-1,5-dibromopentanes as precursors to heteracyclohexanes

• Bryan Ringstrand,
• Martin Oltmanns,
• Jeffrey A. Batt,
• Aleksandra Jankowiak,
• Richard P. Denicola and
• Piotr Kaszynski

Beilstein J. Org. Chem. 2011, 7, 386–393, doi:10.3762/bjoc.7.49

• 3e was prepared in 86% yield by hydrogenation of the corresponding 4-methylenetetrahydropyran 6e in the presence of ZnBr2 to prevent reductive dechlorination (Scheme 7) [46]. Attempts to use diphenyl sulfide as a catalyst poison [47] resulted only in recovery of the starting material. Wittig

The allylic chalcogen effect in olefin metathesis

• Yuya A. Lin and
• Benjamin G. Davis

Beilstein J. Org. Chem. 2010, 6, 1219–1228, doi:10.3762/bjoc.6.140

• examples of such a reaction on proteins. This led to a new benchmark in substrate complexity for cross-metathesis and expanded the potential of olefin metathesis for other applications in chemical biology. The enhanced reactivity of allyl sulfide, along with earlier reports of a similar effect by allylic

• substrates [27][28]. The effect of other allylic chalcogens in olefin metathesis Allyl sulfides are privileged substrates in olefin metathesis While there are many examples of allylic alcohols and ethers in metathesis, examples with allyl sulfide substrates were until recently noticeably few. This is

• amino acids with allyl alcohol mediated by catalyst 4 was investigated. Unexpectedly, S-allylcysteine derivative 21a was the only substrate that afforded a synthetically useful amount of CM product, whereas the reaction of the all carbon analogue homoallylglycine (20) and sulfide derivatives, S-butenyl

Aromatic and heterocyclic perfluoroalkyl sulfides. Methods of preparation

• Vladimir N. Boiko

Beilstein J. Org. Chem. 2010, 6, 880–921, doi:10.3762/bjoc.6.88

• significant. The reaction is carried out by heating a mixture of aryl trichloromethyl sulfide with an excess of SbF3 in the absence of a solvent. For industrial processes, dry hydrogen fluoride is used as the fluorinating agent (Scheme 1). The presence of halogen atoms and electron-withdrawing groups such as

• longer perfluoroalkyl sulfides because the required aryl perchloroalkyl sulfide precursors are not easily accessible [57][58]. However, pentafluoroethyl ethers of various thiophenols (or phenols) can be obtained by the more sequential process as shown in Scheme 2 [59]. Use of mixed (Cl/F

• ) polyhalogenofluoro alkanes as partial fluorinated alkylating agents generates the corresponding sulfides which are appropriate precursors for subsequent conversion to perfluoroalkyl thioethers. For example, α,α-difluoro polyhalogenoalkyl sulfides and α,α-dichlorotrifluoroethyl sulfide can be obtained by reaction of

Synthesis of the fluorescent amino acid rac-(7-hydroxycoumarin-4-yl)ethylglycine

• Manfred Braun and
• Torsten Dittrich

Beilstein J. Org. Chem. 2010, 6, No. 69, doi:10.3762/bjoc.6.69

• acetonedicarboxylate. First, the acid 2 was reduced to the alcohol 3 with borane. The protocol described in the literature [12] was modified, and the reducing agent borane–tetrahydrofuran replaced by the less expensive borane–dimethyl sulfide. This also led to a slight increase in yield (59%). For the planned

• 0 °C. Through the dropping funnel, a 10 M solution of borane–dimethyl sulfide (12 mL, 120 mmol) in THF, diluted with 100 mL of dry THF was added dropwise over 60 min at 0 °C. Stirring was continued at r. t. for 24 h. After cooling to 0 °C, water (10 mL) was cautiously added. The mixture was