Acid, silver, and solvent-free gold-catalyzed hydrophenoxylation of internal alkynes

• Marcia E. Richard,
• Daniel V. Fraccica,
• Kevin J. Garcia,
• Erica J. Miller,
• Rosa M. Ciccarelli,
• Erin C. Holahan,
• Victoria L. Resh,
• Aakash Shah,
• Peter M. Findeis and
• Robert A. Stockland Jr.

Beilstein J. Org. Chem. 2013, 9, 2002–2008, doi:10.3762/bjoc.9.235

• prepared by displacement of dimethyl sulfide from Me2SAuCl by JohnPhos or t-BuXPhos [23][24]. The (NHC)AuCl (NHC = SIMes, IMes, SIPr, IPr) [19][25] precursors as well as arylgold compounds 1–3 [14] were prepared following literature procedures. The arylboronic acids, alkynes, phenols, and Cs2CO3 (powder

Stereoselective synthesis of the C79–C97 fragment of symbiodinolide

• Hiroyoshi Takamura,
• Takayuki Fujiwara,
• Isao Kadota and
• Daisuke Uemura

Beilstein J. Org. Chem. 2013, 9, 1931–1935, doi:10.3762/bjoc.9.228

• (Scheme 4). The synthesis started from commercially available methyl (S)-3-hydroxy-2-methylpropanoate (21), which was converted to alcohol 22 by the known method [22]. Alcohol 22 was treated with 1-phenyl-1H-tetrazole-5-thiol/DEAD/PPh3 to furnish the corresponding PT-sulfide, which was oxidized with H2O2

Organocatalyzed enantioselective desymmetrization of aziridines and epoxides

• Ping-An Wang

Beilstein J. Org. Chem. 2013, 9, 1677–1695, doi:10.3762/bjoc.9.192

• quinine (OC-7) at room temperature. The β-amino sulfides were obtained in high yields (up to 85%) and with moderate enantioselectivities (up to 72% ee). However, OC-10 and OC-11 afforded extremely disappointing results for desymmetrization and the corresponding β-amino sulfide was obtained nearly racemic

Anodic coupling of carboxylic acids to electron-rich double bonds: A surprising non-Kolbe pathway to lactones

• Robert J. Perkins,
• Hai-Chao Xu,
• John M. Campbell and
• Kevin D. Moeller

Beilstein J. Org. Chem. 2013, 9, 1630–1636, doi:10.3762/bjoc.9.186

• the ketene dithioacetal in the absence of a trapping group [21]. The anodic coupling of a carboxylic acid group with a vinyl sulfide and an enol ether were also examined (Table 2). As with earlier alcohol and amine based cyclizations, reactions with the vinyl sulfide coupling partner proceeded much

• better than did their enol ether counterparts [21][22]. In the previous cases, the argument was made that less polar radical cations underwent better trapping reactions with heteroatomic nucleophiles [23], and a similar argument can be made here. The oxidation potential for the vinyl sulfide used in

• intramolecular electron-transfer to form the carboxy radical can occur, the difference in oxidation potentials suggests that the equilibrium would lie on the side of the oxidized olefin. Styrene substrates and additional insights With the ketene dithioacetal, vinyl sulfide, and enol ether substrates, it appeared

Electron self-exchange activation parameters of diethyl sulfide and tetrahydrothiophene

• Martin Goez and
• Martin Vogtherr

Beilstein J. Org. Chem. 2013, 9, 1448–1454, doi:10.3762/bjoc.9.164

• , diethyl sulfide DES and tetrahydrothiophene THTP, for which we have barred the direct deprotonation at Cα by the choice of a suitable sensitizer; for these substrates, a relayed deprotonation is also impossible because they are not sufficiently basic; however, D•+ can stabilize by dimer formation with

• . As we will show, the activation parameters provide evidence that the observed exchange indeed takes place between dimeric radical cations and D. Results and Discussion On the AM1 level, the heats of formation of D and are −92 kJ/mol and −14 kJ/mol for diethyl sulfide DES as opposed to −69 kJ/mol and

• ]; both in acetonitrile versus SCE) the opposite order, even with a numerically similar difference, is calculated for the radical pair with D•+, although observations [28][29] that for bifunctional donors comprising both an amine and a sulfide moiety photoinduced electron transfer occurs exclusively from

Photoinduced synthesis of unsymmetrical diaryl selenides from triarylbismuthines and diaryl diselenides

• Yohsuke Kobiki,
• Shin-ichi Kawaguchi,
• Takashi Ohe and
• Akiya Ogawa

Beilstein J. Org. Chem. 2013, 9, 1141–1147, doi:10.3762/bjoc.9.127

• excess amounts of either starting substrate were employed, the yields of 3aa increased (Table 3, entries 1, 2 and 5). In the case of the reaction of triphenylbismuthine with diphenyl disulfide (4) instead of diphenyl diselenide, diphenyl sulfide 5 was obtained in lower yield with unidentified byproducts

Appel-reagent-mediated transformation of glycosyl hemiacetal derivatives into thioglycosides and glycosyl thiols

• Tamashree Ghosh,
• Abhishek Santra and
• Anup Kumar Misra

Beilstein J. Org. Chem. 2013, 9, 974–982, doi:10.3762/bjoc.9.112

• halide or acetate with thiourea or thioacetate and hydrolysis of the resulting intermediates [26][27]; (b) reaction of hydrogen sulfide gas with glycosyl halides in hydrogen fluoride [39]; (c) treatment of the glycosyl hemiacetal derivatives with Lawesson’s reagent [40] and (d) treatment of 1,6-anhydro

• sugar derivative [41] and glycosyl trichloroacetimidate derivatives [42] with bis(trimethylsilyl) sulfide. However, most of the reactions have several inherent shortcomings, such as the use of reactive starting materials, longer reaction time, multiple steps, unsatisfactory yield, formation an isomeric

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