Aluminacyclopentanes in the synthesis of 3-substituted phospholanes and α,ω-bisphospholanes

• Vladimir A. D’yakonov,
• Alevtina L. Makhamatkhanova,
• Rina A. Agliullina,
• Leisan K. Dilmukhametova,
• Tat’yana V. Tyumkina and
• Usein M. Dzhemilev

Beilstein J. Org. Chem. 2016, 12, 406–412, doi:10.3762/bjoc.12.43

• gel the solvent was evaporated to give a colorless oil. 3-Hexyl-1-phenylphospholane-1-sulfide (4b) in the mixture in a ratio of 3:2: Calculated for C16H25PS: C, 68.53%; H, 8.99%; found: C, 68.4%; H, 8.0%; 1H NMR (400.13 MHz, CDCl3) δ 0.91 (t, 3J = 6.8 Hz, 6H, C(6')H), 1.25–1.43 (m, 16H, C(2')H, C(3')H

A journey in bioinspired supramolecular chemistry: from molecular tweezers to small molecules that target myotonic dystrophy

• Steven C. Zimmerman

Beilstein J. Org. Chem. 2016, 12, 125–138, doi:10.3762/bjoc.12.14

• mid to late 1970s. I was fortunate to do undergraduate research with Professor Hans J. Reich, investigating the mechanism of the singlet oxygen reaction with alkenes and studying the oxidation of selenide/sulfide mixtures using ozone and singlet oxygen [1]. In my senior year, I took three graduate

Synthesis of Xenia diterpenoids and related metabolites isolated from marine organisms

• Tatjana Huber,
• Lara Weisheit and
• Thomas Magauer

Beilstein J. Org. Chem. 2015, 11, 2521–2539, doi:10.3762/bjoc.11.273

• for the key intramolecular acyl transfer reaction to form the cyclononene motif. After sodium periodate oxidation of sulfide 56 to the corresponding sulfoxide, addition of lithium diisopropylamide initiated the intramolecular acyl transfer and led to formation of cyclononene 57 in quantitative yield

Beyond catalyst deactivation: cross-metathesis involving olefins containing N-heteroaromatics

• Kevin Lafaye,
• Cyril Bosset,
• Lionel Nicolas,
• Amandine Guérinot and
• Janine Cossy

Beilstein J. Org. Chem. 2015, 11, 2223–2241, doi:10.3762/bjoc.11.241

• , biologically relevant conditions were selected (rt, t-BuOH/H2O) and CM involving allyl sulfides that contain functional groups commonly found in DNA-intercalators and N-heteroaromatics were investigated. When a quinoline was present on the allylic sulfide, allylic alcohol was found to be the unique suitable

• partner among the tested olefins. In addition, 20 equiv of allylic alcohol were required and the CM product was obtained in a moderate 53% yield. Cross-metathesis of 81 with amide 83 or alkene 85 gave no conversion (Scheme 32). In the presence of a quinoxaline moiety on the allyl sulfide, the CM reaction

• erythromycin. Retrosynthesis of haminol A. CM involving 3-vinylpyridine 70 with 71 and vinylpyridine 70 with 73. Revised retrosynthesis of haminol A. CM between 78 and crotonaldehyde. Hypothesized deactivation pathway. CM involving an allyl sulfide containing a quinoline. CM involving allylic sulfide

Aerobic addition of secondary phosphine oxides to vinyl sulfides: a shortcut to 1-hydroxy-2-(organosulfanyl)ethyl(diorganyl)phosphine oxides

• Svetlana F. Malysheva,
• Alexander V. Artem’ev,
• Nina K. Gusarova,
• Nataliya A. Belogorlova,
• Alexander I. Albanov,
• C. W. Liu and
• Boris A. Trofimov

Beilstein J. Org. Chem. 2015, 11, 1985–1990, doi:10.3762/bjoc.11.214

• gain a primary insight into the reaction mechanism, several experiments were carried out. On example of phosphine oxide 1a and vinyl sulfide 2c, we have shown that the reaction proceeds in the dark with the same efficiency as in the light. Therefore, the photochemical pathway of the reaction is hardly

• the P(O)H species to molecular oxygen has been reported for example for Ph2P(O)H [30]. Then, the radical addition of A to vinyl sulfide, proceeding in an anti-Markovnikov manner, takes place. Subsequently, a 1,2-intramolecular transfer of an H atom within the radical adduct B (from PCH2 group to

• phosphine oxides to vinyl sulfides under solvent- and catalyst-free conditions, which provides an efficient approach to hitherto unknown 1-hydroxy-2-(organosulfanyl)ethyl(diorganyl)phosphine oxides in one step. The synthesized phosphine oxides, bearing hydroxy and sulfide functions, represent prospective

[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

• easily available by the treatment of 1,3-dithiol-2-ylium salts with sodium sulfide [21]. Thus, by treating perchlorates 5a–c with sodium sulfide nonahydrate, at room temperature in ethanol, we obtained 4-([2.2]paracyclophan-4-yl)-1,3-dithiol-2-thione (6) as a yellow solid in 41% isolated yield (Scheme 2

Lewis acid-promoted hydrofluorination of alkynyl sulfides to generate α-fluorovinyl thioethers

• Davide Bello and
• David O'Hagan

Beilstein J. Org. Chem. 2015, 11, 1902–1909, doi:10.3762/bjoc.11.205

• as it is a less acidic reagent compared to HF·Py, and thus activation of alkynyl sulfide 1a was explored by addition of a Lewis acid. At this stage we were pleased to find that the use of BF3·Et2O allowed for a conversion of over 90% of 1a (16 h at room temperature). However, products 2a and 3a were

• ) were added to a mixture of sulfide 1a and 3HF·Et3N (3.0 equivalents) at 0 ºC, but no reactions took place under these conditions. The HBF4·SiO2 reagent was chosen as a solid phase-supported HBF4 equivalent [14]; carrying out the reaction in the presence of this reactant and 3HF·Et3N led to complete

• decomposition of sulfide 1a. With TiF4 the overall conversion was around 70%, and the hydrofluorinated product could be isolated in an improved yield (42%, 4:1 Z:E). In order to improve the reaction yields, reactions with the BF3·Et2O/3HF·Et3N and TiF4/3HF·Et3N systems were optimised and the outcomes described

Design and synthesis of polycyclic sulfones via Diels–Alder reaction and ring-rearrangement metathesis as key steps

• Sambasivarao Kotha and
• Rama Gunta

Beilstein J. Org. Chem. 2015, 11, 1373–1378, doi:10.3762/bjoc.11.148

• methanesulfonyl chloride in the presence of triethylamine as a base to obtain the dimesylate 3 (89%). Next, compound 3 was subjected to a cyclization reaction by treating with sodium sulfide nonahydrate (Na2S·9H2O) using 20% Aliquat® 336 as a phase–transfer catalyst (PTC) to produce the known sulfide 5 (83%) [31

• ]. Having the sulfide 5 in hand, our next task was to prepare sulfone 6. In this regard, Trost and Curran [32] have reported the conversion of sulfides to sulfones in the presence of other common functional groups such as olefins by reacting with the oxidizing agent, potassium hydrogen persulfate (KHSO5

One-pot odourless synthesis of thioesters via in situ generation of thiobenzoic acids using benzoic anhydrides and thiourea

• Mohammad Abbasi and
• Reza Khalifeh

Beilstein J. Org. Chem. 2015, 11, 1265–1273, doi:10.3762/bjoc.11.141

• . On the other hand, the usual methods for preparing thioacids involve the action of toxic and unpleasant smelling, gaseous hydrogen sulfide on carboxylic acid derivatives [46][47]. Also, thioacids as thiols have a strong and repulsive smell. The in situ generation of thioacids using odourless, easy to

A new and convenient synthetic way to 2-substituted thieno[2,3-b]indoles

• Roman A. Irgashev,
• Arseny A. Karmatsky,
• Gennady L. Rusinov and
• Valery N. Charushin

Beilstein J. Org. Chem. 2015, 11, 1000–1007, doi:10.3762/bjoc.11.112

• unequivocally by X-ray crystallography analysis, thus supporting the data of 1H and 13C NMR spectroscopy (Figure 2). The Lawesson’s reagent appears to act firstly as a source of hydrogen sulfide to reduce the C=C double bond in compound 10a, and secondly, as the thiation agent to form thieno[2,3-b]indole 12a by

Design, synthesis and photochemical properties of the first examples of iminosugar clusters based on fluorescent cores

• Mathieu L. Lepage,
• Antoine Mirloup,
• Manon Ripoll,
• Fabien Stauffert,
• Anne Bodlenner,
• Raymond Ziessel and
• Philippe Compain

Beilstein J. Org. Chem. 2015, 11, 659–667, doi:10.3762/bjoc.11.74

• bearing a tetraethylene glycol chain tethered to the boron center via an ethynyl bond proved difficult. The use of copper(I) bromide dimethyl sulfide complex [63] at room temperature led to a complex mixture of products. Better results were obtained with copper(II) sulfate and sodium ascorbate under

On the strong difference in reactivity of acyclic and cyclic diazodiketones with thioketones: experimental results and quantum-chemical interpretation

• Andrey S. Mereshchenko,
• Alexey V. Ivanov,
• Viktor I. Baranovskii,
• Grzegorz Mloston,
• Ludmila L. Rodina and
• Valerij A. Nikolaev

Beilstein J. Org. Chem. 2015, 11, 504–513, doi:10.3762/bjoc.11.57

• assumed that the mechanism includes the following steps [12][31][32]: 1,5-electrocyclization of C=S ylide 7’d (step a), 1,3-electrocyclization of C=S ylide 7’d (step b), disproportionation of the thiirane 4’d dimer into thiirane S-sulfide 8’d and alkene 5’d (step c). The subsequent decomposition of

• thiirane-S-sulfide 8’d (step d) and the tetramerization of the extruded S2 molecule results in the formation of the most thermodynamically stable, rhombic modification of sulfur S8 (step e). The obtained computational results for this process are summarized in Table 4 (the data for the Gibbs free energy

• # = 23.8 kcal·mol−1), the thermodynamically more stable alkene 5’d is accumulated in the reaction mixture with time even at room temperature. As for a disproportionation mechanism of two thiirane molecules 4’d (step c) into thiirane S-sulfide 8’d and alkene 5’d, followed by the decomposition of the

Chemoselective O-acylation of hydroxyamino acids and amino alcohols under acidic reaction conditions: History, scope and applications

• Tor E. Kristensen

Beilstein J. Org. Chem. 2015, 11, 446–468, doi:10.3762/bjoc.11.51

• the copper salt with hydrogen sulfide. This methodology has subsequently been employed in a more generic sense as a preparative method for synthesis of acrylic side-chain derivatives of amino acids such as lysine, ornithine, tyrosine and serine [6][7][8], having modified the original technique by

Highly selective electrochemical fluorination of dithioacetal derivatives bearing electron-withdrawing substituents at the position α to the sulfur atom using poly(HF) salts

• Bin Yin,
• Shinsuke Inagi and
• Toshio Fuchigami

Beilstein J. Org. Chem. 2015, 11, 85–91, doi:10.3762/bjoc.11.12

• those of the corresponding sulfides having a single phenylthio group. Although a detailed reason is not clear at present, the additional phenylthio group does not act as an electroauxiliary, but acts as an electron-withdrawing group. As shown in Table 1, the oxidation potentials of sulfide 1g and

Recent advances in the electrochemical construction of heterocycles

• Robert Francke

Beilstein J. Org. Chem. 2014, 10, 2858–2873, doi:10.3762/bjoc.10.303

• has to be carried out at 0 °C in order to stabilize the reactive alkoxysulfonium species. Analogously to Swern- and Moffat-type reactions, this key intermediate is then converted to ketone 8 by quenching with NEt3 at slightly elevated temperatures under elimination of dimethyl sulfide. Alternatively

Expeditive synthesis of trithiotriazine-cored glycoclusters and inhibition of Pseudomonas aeruginosa biofilm formation

• Meriem Smadhi,
• Sophie de Bentzmann,
• Anne Imberty,
• Marc Gingras,
• Raoudha Abderrahim and
• Peter G. Goekjian

Beilstein J. Org. Chem. 2014, 10, 1981–1990, doi:10.3762/bjoc.10.206

• the hexavalent benzene cluster [30], which may be attributed to differences in rigidity and hydrophobicity between the two systems [25]. It thus appears that the direct diaryl sulfide bridge presents a more optimal degree of semi-rigidity. The affinities of the designed glycoconjugates with lecA and

Application of cyclic phosphonamide reagents in the total synthesis of natural products and biologically active molecules

• Thilo Focken and
• Stephen Hanessian

Beilstein J. Org. Chem. 2014, 10, 1848–1877, doi:10.3762/bjoc.10.195

Automated solid-phase peptide synthesis to obtain therapeutic peptides

• Veronika Mäde,
• Sylvia Els-Heindl and
• Annette G. Beck-Sickinger

Beilstein J. Org. Chem. 2014, 10, 1197–1212, doi:10.3762/bjoc.10.118

• modified by fatty acid acylation [97]. The synthesis of these lipidated peptides can be performed by amidation, S- or O-esterification as well as thioether or -sulfide formation. Owing to the strength of the covalent bonds, amidation and O-esterfication are preferred over the other strategies [97

End-group-functionalized poly(N,N-diethylacrylamide) via free-radical chain transfer polymerization: Influence of sulfur oxidation and cyclodextrin on self-organization and cloud points in water

• Sebastian Reinelt,
• Daniel Steinke and
• Helmut Ritter

Beilstein J. Org. Chem. 2014, 10, 680–691, doi:10.3762/bjoc.10.61

• sulfide) containing copolymers is based on the oxidation of thioethers to more hydrophilic sulfoxides or sulfones [11][12]. The specific sulfoxidation of a polymer bound end-group, which is in the focus of our present work, has not yet been investigated. Polymeric materials exhibiting sensitivity to

Direct and indirect single electron transfer (SET)-photochemical approaches for the preparation of novel phthalimide and naphthalimide-based lariat-type crown ethers

• Dae Won Cho,
• Patrick S. Mariano and
• Ung Chan Yoon

Beilstein J. Org. Chem. 2014, 10, 514–527, doi:10.3762/bjoc.10.47

• corresponding polyether side chain containing the lariat-type azacrown ethers 47a–c exclusively (Scheme 11). As observed in earlier studies [34], the initially formed photoproducts undergo in situ dehydration to produce the vinyl sulfide products 46a–c [82]. The photoreactions shown in Scheme 10 and Scheme 11

Carbenoid-mediated nucleophilic “hydrolysis” of 2-(dichloromethylidene)-1,1,3,3-tetramethylindane with DMSO participation, affording access to one-sidedly overcrowded ketone and bromoalkene descendants^§

• Rudolf Knorr,
• Thomas Menke,
• Johannes Freudenreich and
• Claudio Pires

Beilstein J. Org. Chem. 2014, 10, 307–315, doi:10.3762/bjoc.10.28

• the solvent at ≥100 °C through an initial chlorine particle transfer to give a Cl,K-carbenoid. This short-lived intermediate disclosed its occurrence through a reversible proton transfer which competed with an oxygen transfer from DMSO that created dimethyl sulfide. The presumably resultant transitory

• the present “hydrolysis” of 6 became evident when pure dimethyl sulfide (Me2S, boiling point 37 °C) distilled from the reaction vessel into a cold trap during such a preparation of 10. In situ 1H NMR spectra revealed the obligatory formation of ca. one equivalent of Me2S (δH = 2.06 ppm). Small

• derivatives are preferable. “Hydrolysis” of 6, and the KOR/dimsyl-K (11) system. Proposed carbenoid pathway from 6 to acid 10 and dimethyl sulfide (Me2S) in DMSO as the solvent. Proposed pathway to the main side-product 23 formed by nucleophilic addition of 11 to C-2 of 6. Possible course of the carbenoid

Synthesis of five- and six-membered cyclic organic peroxides: Key transformations into peroxide ring-retaining products

• Alexander O. Terent'ev,
• Dmitry A. Borisov,
• Vera A. Vil’ and
• Valery M. Dembitsky

Beilstein J. Org. Chem. 2014, 10, 34–114, doi:10.3762/bjoc.10.6

•  83) [336]. The synthesis of the sulfonyl-containing 1,2-dioxane 2-(benzyloxy)-2,6-dimethyl-6-(phenylsulfonylmethyl)-7,8-dioxabicyclo[3.3.1]nonane )297a), included the following steps: oxidation of the sulfide group in 2,6-dimethyl-6-(phenylthiomethyl)-7,8-dioxabicyclo[3.3.1]nonan-2-ol (295) to form

Less reactive dipoles of diazodicarbonyl compounds in reaction with cycloaliphatic thioketones – First evidence for the 1,3-oxathiole–thiocarbonyl ylide interconversion

• Valerij A. Nikolaev,
• Alexey V. Ivanov,
• Ludmila L. Rodina and
• Grzegorz Mlostoń

Beilstein J. Org. Chem. 2013, 9, 2751–2761, doi:10.3762/bjoc.9.309

• . It is well established that the elimination of a sulfur atom S1 from thiirane 8e' has a high positive ΔG value (86.6 kcal·mol−1). It seems that the desulfurization process occurs via the interaction of two molecules of the thiirane, which results in the formation of an intermediate thiirane S-sulfide

Advancements in the mechanistic understanding of the copper-catalyzed azide–alkyne cycloaddition

• Regina Berg and
• Bernd F. Straub

Beilstein J. Org. Chem. 2013, 9, 2715–2750, doi:10.3762/bjoc.9.308

• in aqueous media is so facile that it even occurs in strongly acidic solutions [117]. Sulfur-based ligands are rarely used for CuAAC catalysis. However, the copper(I) bromide dimethyl sulfide complex [CuBr·SMe2]2 is well soluble in organic media, commercially available and shows good catalytic

Synthetic scope and DFT analysis of the chiral binap–gold(I) complex-catalyzed 1,3-dipolar cycloaddition of azlactones with alkenes

• María Martín-Rodríguez,
• Luis M. Castelló,
• Carmen Nájera,
• José M. Sansano,
• Olatz Larrañaga,
• Abel de Cózar and
• Fernando P. Cossío

Beilstein J. Org. Chem. 2013, 9, 2422–2433, doi:10.3762/bjoc.9.280

• ) complexes 3 and 4, identified and characterized by Puddephatt’s group [X = trifluoroacetate (TFA)] [29][30][31], were obtained from NaAuCl4 and dimethyl sulfide and the corresponding amount of the chiral Binap ligand. Finally, the anion interchange was promoted by the addition of an equivalent amount of