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

• dichlorophosphines (R′PCl2). Hydrogen peroxide oxidation and treatment with S8 of the synthesized phospholanes and α,ω-bisphospholanes afforded the corresponding 3-alkyl(aryl)-1-alkyl(phenyl)phospholane 1-oxides, 3-alkyl(aryl)-1-alkyl(phenyl)phospholane 1-sulfides, bisphospholane 1,1'-dioxides, and bisphospholane

• affords phospholane 1-sulfides 4а–h also in quantitative yields (Scheme 3). In the 31Р NMR spectra of phospholane oxides 3a–h and phospholane sulfides 4a–h, the phosphorus signal shifts downfield to ca. 57–70 ppm relative to the initial phospholanes, and the heteronuclear constants 1J(31P13C2) and 1J

• the synthesis of five-membered cyclic organophosphorus compounds, we developed a preparative process for the one-pot conversion of aluminacyclopentanes, obtained in situ by catalytic cycloalumination of olefins or diolefins with AlEt3, to phospholanes, phospholane oxides or phospholane sulfides

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

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

• Chemistry, National Dong Hwa University, Hualien 97401, Taiwan 10.3762/bjoc.11.214 Abstract Secondary phosphine oxides react with vinyl sulfides (both alkyl- and aryl-substituted sulfides) under aerobic and solvent-free conditions (80 °C, air, 7–30 h) to afford 1-hydroxy-2-(organosulfanyl)ethyl(diorganyl

• )phosphine oxides in 70–93% yields. Keywords: addition; green method; phosphine oxides; regioselectivity; vinyl sulfides; Findings Tertiary phosphines and phosphine chalcogenides are important organophosphorus compounds that are widely used in industry, organic synthesis, polymer science, medicinal and

• ][20] as well as transition metal catalysts [21][22][23]. Also, examples of the microwave-assisted [24][25] and photoinduced [26] addition are described. Recently, on example of secondary phosphines [27] as well as secondary phosphine sulfides [28] and selenides [29], it has been disclosed that the

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

• Davide Bello David O'Hagan University of St Andrews, School of Chemistry, North Haugh, St Andrews, Fife, KY16 9ST, UK 10.3762/bjoc.11.205 Abstract A new method for the preparation of α-fluorovinyl thioethers is reported which involves the hydrofluorination of alkynyl sulfides with 3HF·Et3N, a

• thioester enols and enolates, important intermediates in enzymatic C–C bond forming reactions. The method opens access to appropriate analogues for investigations in this direction. Keywords: alkynyl sulfides; α-fluorovinyl thioethers; hydrofluorination; Lewis acids; organofluorine; Introduction

• , have a spatial and electrostatic profile consistent with the potential to mimic these enzyme intermediates. There is limited literature for preparing such analogues. We have previously described the preparation of α-fluorovinyl thioethers by hydrofluorination of the corresponding alkynyl sulfides using

Preparative semiconductor photoredox catalysis: An emerging theme in organic synthesis

• David W. Manley and
• John C. Walton

Beilstein J. Org. Chem. 2015, 11, 1570–1582, doi:10.3762/bjoc.11.173

• )phthalimide was employed by the Overman group in their synthesis of (−)-aplyviolene [11]. Heterogeneous PRCs form a second class consisting of semiconductor materials. These are generally metal oxides or sulfides in the form of fine particles that consequently have the additional advantage of easily being

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

• ]. 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

Highly selective palladium–benzothiazole carbene-catalyzed allylation of active methylene compounds under neutral conditions

• Antonio Monopoli,
• Pietro Cotugno,
• Carlo G. Zambonin,
• Francesco Ciminale and
• Angelo Nacci

Beilstein J. Org. Chem. 2015, 11, 994–999, doi:10.3762/bjoc.11.111

• , catalyst loading, temperature and solvents (Table 1). With regard to the influence of ligands, the efficiency of benzothiazole–carbene was compared with that of sulfides II and III, both in the presence and in the absence of PPh3, as it is well known that also chelating N-heterocyclic ligands bearing

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

• mind, we studied comparatively the anodic fluorination of dithioacetal derivatives having various electron-withdrawing groups at their α-positions using various poly(HF) salts [28]. Results and Discussion Various α-substituted methyl phenyl sulfides, 1a, 1c, 1e, and 1g, and their α-phenylthio

• exhibited irreversible multiple oxidation peaks and the first oxidation peak potentials are summarized in Table 1. It was expected that the introduction of an additional phenylthio group to the α-position of the sulfides would decrease their oxidation potentials. However, unexpectedly they are higher than

• 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

• coupling. In addition to enol ethers 1, vinyl sulfides and ketene acetals have successfully been cyclized according to Scheme 2 [34][35][36]. An interesting modification of this anodic coupling method was achieved by Yoshida, Nokami and co-workers using the “cation pool” concept [37][38][39]. In this

Magnesium bis(monoperoxyphthalate) hexahydrate as mild and efficient oxidant for the synthesis of selenones

• Andrea Temperini,
• Massimo Curini,
• Ornelio Rosati and
• Lucio Minuti

Beilstein J. Org. Chem. 2014, 10, 1267–1271, doi:10.3762/bjoc.10.127

• oxidant and it has been employed for the selective oxidation of sulfides to the corresponding sulfoxides, for the preparation of α-methylenecyclohexane [16] and glycosyl sulfoxides [17]. Compared to the widely used peroxy acid MCPBA, MMPP has similar chemical properties, but it is a halogen-free reagent

Preparation of phosphines through C–P bond formation

• Iris Wauters,
• Wouter Debrouwer and
• Christian V. Stevens

Beilstein J. Org. Chem. 2014, 10, 1064–1096, doi:10.3762/bjoc.10.106

• losses during purification, the phosphines are sometimes deliberately transformed into the corresponding oxides (or sulfides). However, this requires an additional reduction step afterwards to get the phosphine back [10][11][12][13][14][15]. Therefore phosphines are sometimes protected by generation of

• formed exclusively and isolated as the phosphine sulfides 140 to prevent lower yields by oxidation to the corresponding oxides. The phosphines 141 were obtained by radical reduction of 140 with tris(trimethylsilyl)silane (TTMSS). However, when Kumaraswamy et al. explored the copper-catalyzed

Tailoring of organic dyes with oxidoreductive compounds to obtain photocyclic radical generator systems exhibiting photocatalytic behavior

• Christian Ley,
• Julien Christmann,
• Ahmad Ibrahim,
• Luciano H. Di Stefano and
• Xavier Allonas

Beilstein J. Org. Chem. 2014, 10, 936–947, doi:10.3762/bjoc.10.92

• ]. Hydrogen donor coinitiators could be amines [33][34][35][36][37][38], ethers [39][40], sulfides [41][42][43] or thiols [43][44][45]. Electron transfer coinitiators could be borate salts [46][47], iodonium [48][49] or triazine [32] derivatives. However, if Type II PIS gain sensitivity in the visible part of

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

Reaction of 2,2,4,4-tetrakis(trifluoromethyl)-1,3-dithiethane with N-vinyl compounds

• Viacheslav A. Petrov and
• Will Marshall

Beilstein J. Org. Chem. 2013, 9, 2615–2619, doi:10.3762/bjoc.9.295

• sulfides, cyclic dienes and styrenes [1][2], fluoride anion-catalyzed reactions of compound 1 with vinyl ethers [1][3][4], vinyl sulfides [3], ketene dimethylacetal [5], styrenes [6][7], cyclic dienes [8] and quadricyclane [9]. At this point, no data for the reaction of HFTA or HFTA dimer with vinylamines

Recent advances in transition metal-catalyzed Csp²-monofluoro-, difluoro-, perfluoromethylation and trifluoromethylthiolation

• Grégory Landelle,
• Armen Panossian,
• Sergiy Pazenok,
• Jean-Pierre Vors and
• Frédéric R. Leroux

Beilstein J. Org. Chem. 2013, 9, 2476–2536, doi:10.3762/bjoc.9.287

• ]. In the same paper, the authors showed that cobalt perchlorate could also improve the yield of the uncatalyzed reaction. Iron sulfate, on the other hand, gave the same yield as in the absence of added metals. 4 Catalytic trifluoromethylthiolation Aryl trifluoromethyl sulfides (ArSCF3) play an

• stability of molecules in acidic medium. One can place this substituent next to the ever-present CF3 and the emerging OCF3 substituent [55][56][130]. In contrast, aryl trifluoromethyl sulfides are key intermediates for the preparation of trifluoromethyl sulfoxides or sulfones. Aryl trifluoromethyl sulfides

• can be obtained via reaction of trifluoromethylthiolate with an electrophile like aryl halides. On the other hand, they can also be obtained by reacting aryl sulfides or disulfides under nucleophilic or radical conditions with a trifluoromethylation reagent [16][55][124]. Very recently, several

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

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

• their radical cations, which were generated by photoinduced electron transfer from the sulfides to excited 2,4,6-triphenylpyrylium cations, was investigated by time-resolved measurements of chemically induced dynamic nuclear polarization (CIDNP) in acetonitrile. The strongly negative activation

• solvent reorganization. Keywords: CIDNP; electron transfer; free radicals; kinetics; photochemistry; pyrylium salts; self-exchange; sulfides; Introduction Single-electron transfer is probably the simplest chemical process of an organic molecule, because usually no full bonds are broken or formed. For

• reaction into a hydrogen abstraction. In a previous report on two aliphatic amines [20], we have used time-resolved CIDNP experiments to distinguish between the ensuing electron and hydrogen self-exchanges of D•+ and . In the present work, we investigate two structurally similar aliphatic sulfides

Use of 3-[¹⁸F]fluoropropanesulfonyl chloride as a prosthetic agent for the radiolabelling of amines: Investigation of precursor molecules, labelling conditions and enzymatic stability of the corresponding sulfonamides

• Reik Löser,
• Steffen Fischer,
• Achim Hiller,
• Martin Köckerling,
• Uta Funke,
• Aurélie Maisonial,
• Peter Brust and
• Jörg Steinbach

Beilstein J. Org. Chem. 2013, 9, 1002–1011, doi:10.3762/bjoc.9.115

• chlorides can be generated by oxidation with aqueous chlorine from a variety of organosulfur species such as thiols, sulfides, disulfides, thioesters, isothiouronium salts, xanthates and thiocyanates [22]. The latter class of organic sulfur compounds seems to be most advantageous, as organic thiocyanates

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

• microwave irradiation the time was drastically reduced to 2 h. Both procedures are simple and involve a low-cost catalytic system. This methodology was also applied to the “one-pot” synthesis of target heterocycles, such as 3H-benzo[c][1,2]dithiol-3-one and 2-methylbenzothiazole, alkyl aryl sulfides, diaryl

• disulfides and asymmetric diaryl sulfides in good yields. Keywords: catalysis; copper; cross-coupling; potassium thioacetate; sulfur heterocycles; Introduction Aromatic sulfur compounds including sulfides and heterocycles are relevant in chemical, pharmaceutical and materials industries [1][2][3]. As a

• diverse heterocycles containing sulfur atoms by intra- [42][43][44] and intermolecular [45][46][47] reactions. Aryl thioesters are versatile intermediates for the synthesis of a variety of sulfur compounds including aryl thiols, aryl alkyl sulfides, aryl sulfenyl chlorides, aryl sulfonyl chlorides [48

Stereoselective synthesis of tetrasubstituted alkenes via a sequential carbocupration and a new sulfur–lithium exchange

• Andreas Unsinn,
• Cora Dunst and
• Paul Knochel

Beilstein J. Org. Chem. 2012, 8, 2202–2206, doi:10.3762/bjoc.8.248

• due to steric hindrance and proceeds only if electron-withdrawing groups are attached to the alkyne unit to facilitate the carbometalation step. Recently, we studied the chemistry of alkenyl sulfides and their use for carbometalation extensively [13]. Therefore, we envisioned using an alkynyl

The chemistry of bisallenes

• Henning Hopf and
• Georgios Markopoulos

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

Facile synthesis of functionalized tetrahydroquinolines via domino Povarov reactions of arylamines, methyl propiolate and aromatic aldehydes

• Jing Sun,
• Hong Gao,
• Qun Wu and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2012, 8, 1839–1843, doi:10.3762/bjoc.8.211

• dienophiles, vinyl enol ethers, vinyl enamides, vinyl sulfides, cyclopentadienes, indenes, alkynes and enamines have been mostly used in this method [12][13][14][15][16][17][18][19][20][21][22]. β-Enamino esters [23][24][25][26], which may be readily generated in situ by the addition of a primary amine to

Carbamate-directed benzylic lithiation for the diastereo- and enantioselective synthesis of diaryl ether atropisomers

• Abigail Page and
• Jonathan Clayden

Beilstein J. Org. Chem. 2011, 7, 1327–1333, doi:10.3762/bjoc.7.156

• ], sulfides and sulfones [13], and many of the methods we developed for their asymmetric synthesis employed dynamic resolution techniques under kinetic or thermodynamic control [6][11][13][14][15][16]. The mechanistic possibilities associated with dynamic resolution were initially elaborated by Beak for

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

• reactions mediated by recyclable copper oxide nanoparticles under ligand free conditions. This protocol avoids foul smelling thiols, for the synthesis of a variety of symmetrical diaryl sulfides, via the cross-coupling of different aryl halides with potassium thiocyanate, affording corresponding products in

• moderate to excellent yields. Keywords: aryl halides; aryl sulfides; copper oxide; cross-coupling; ligand free; potassium thiocyanate; recyclable; Introduction After the discovery of copper-promoted Ullmann reaction [1][2][3] for the construction of carbon-hetero atom bonds, several protocols have been

• reported over the years to establish C–N, C–O, and C–S linkages. Carbon–sulfur bonds are widespread, occurring in numerous pharmaceutically and biologically active compounds [4][5][6][7][8]. A large variety of aryl sulfides are in use for diverse clinical applications in the treatment of cancer [9], HIV

Solvent- and ligand-induced switch of selectivity in gold(I)-catalyzed tandem reactions of 3-propargylindoles

• Estela Álvarez,
• Delia Miguel,
• Patricia García-García,
• Manuel A. Fernández-Rodríguez,
• Félix Rodríguez and
• Roberto Sanz

Beilstein J. Org. Chem. 2011, 7, 786–793, doi:10.3762/bjoc.7.89

• esters have been extensively investigated. In these processes the gold-carbenoid species generated are able to undergo a wide variety of further transformations [8][9][10][11]. In addition, propargylic sulfides have also been reported as useful substrates for this type of process, participating in