Selective and scalable oxygenation of heteroatoms using the elements of nature: air, water, and light

• Damiano Diprima,
• Hannes Gemoets,
• Stefano Bonciolini and
• Koen Van Aken

Beilstein J. Org. Chem. 2023, 19, 1146–1154, doi:10.3762/bjoc.19.82

• phosphine oxide, and selenides to selenoxides. Sulfoxide, phosphine oxide, and selenoxide-containing molecules have diverse applications in the pharmaceutical industry [10], as chiral auxiliaries or as ligands for asymmetric metal catalysis [11], and in materials such as polymers [12][13] and flame

• reaction conditions were also applicable to substrates containing other heteroatoms (i.e., P and Se). This allowed us to broaden the scope of the protocol to phosphinoxides (2o, 2p) from phosphines, organophosphates (2q, 2r) from organophosphites, and selenoxide 2s from selenides. Finally, to prove the

• presence of water has a significant impact on both the kinetics and selectivity. Therefore, we present an extra alternative pathway (Scheme 5), similar to what has been shown in an electrochemical setting for the oxidation of sulfides or selenides [38][39][40][41]. Herein, the oxygen in the end product

Synthesis of novel alkynyl imidazopyridinyl selenides: copper-catalyzed tandem selenation of selenium with 2-arylimidazo[1,2-a]pyridines and terminal alkynes

• Mio Matsumura,
• Kaho Tsukada,
• Kiwa Sugimoto,
• Yuki Murata and
• Shuji Yasuike

Beilstein J. Org. Chem. 2022, 18, 863–871, doi:10.3762/bjoc.18.87

• Mio Matsumura Kaho Tsukada Kiwa Sugimoto Yuki Murata Shuji Yasuike School of Pharmaceutical Sciences, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya 464-8650, Japan 10.3762/bjoc.18.87 Abstract Alkynyl selenides have attracted considerable research interest recently, owing to

• their applications in the biological and pharmaceutical fields. The Cu-catalyzed tandem reaction for the synthesis of novel alkynyl imidazopyridinyl selenides is presented. A one-pot synthesis route afforded alkynyl imidazopyridinyl selenides in moderate to good yields. This was achieved by a two-step

• with potential bioactivity, has been reported [4][5][6][7]. Similarly, organoselenium compounds have also received increased attention in recent years due to their promising applications as bioactive substances in drug discovery [8]. Among these compounds, alkynyl selenides have attracted interest in

A Se···O bonding catalysis approach to the synthesis of calix[4]pyrroles

• Qingzhe Tong,
• Zhiguo Zhao and
• Yao Wang

Beilstein J. Org. Chem. 2022, 18, 325–330, doi:10.3762/bjoc.18.36

• bonding interactions between phosphonium selenides and carbonyls can significantly activate carbonyl groups [41][42][43], thus providing a new opportunity to develop carbonyl chemistry. To expand the catalysis capability of chalcogen bonding interactions, we envisioned that consecutive condensations

Catalyzed and uncatalyzed procedures for the syntheses of isomeric covalent multi-indolyl hetero non-metallides: an account

• Ranadeep Talukdar

Beilstein J. Org. Chem. 2021, 17, 2102–2122, doi:10.3762/bjoc.17.137

• -hydrogen in the diallylsulfoxide (123) did not allow any Pummerer rearrangement [88][89]. Selenides In 1997, Showalter synthesized bis(indol-2-yl)selanes (or selenides) 130 having potential tyrosine kinase inhibitor activities [90][91]. The synthesis was achieved by reacting diselenium dichloride with (R

• obtaining diaryl sulfides [117]. Selenides Along with the oxygen insertion, Black et al. also performed the oxidative selenium insertion into the C-7 position of highly electrophilic 2-methylindole derivative 184. The dual role of selenium dioxide consists of activation of the C-7 position giving the

• 6,6’-bis(indolyl) ethers. Synthesis of bis(indol-7-yl) ether. Synthesis of di(indol-5-yl)sulfide (183). Syntheses of 2,2’-diformyl-7,7’-bis(indolyl)selenides.

Recent progress in the synthesis of homotropane alkaloids adaline, euphococcinine and N-methyleuphococcinine

• Dimas J. P. Lima,
• Antonio E. G. Santana,
• Michael A. Birkett and
• Ricardo S. Porto

Beilstein J. Org. Chem. 2021, 17, 28–41, doi:10.3762/bjoc.17.4

• (−)-adaline (1) and (+)-euphococcinine (2). The cyclooctatetraene derived selenides 82 and (+)-92 are, at some point, similar to the one obtained by Renbaun in the (−)-adaline (1) synthesis. Renbaun generated the quaternary center by adding a chiral amine to the cyclooctatetraene system. On the other hand

Synthesis and anticancer activity of bis(2-arylimidazo[1,2-a]pyridin-3-yl) selenides and diselenides: the copper-catalyzed tandem C–H selenation of 2-arylimidazo[1,2-a]pyridine with selenium

• Mio Matsumura,
• Tsutomu Takahashi,
• Hikari Yamauchi,
• Shunsuke Sakuma,
• Yukako Hayashi,
• Tadashi Hyodo,
• Tohru Obata,
• Kentaro Yamaguchi,
• Yasuyuki Fujiwara and
• Shuji Yasuike

Beilstein J. Org. Chem. 2020, 16, 1075–1083, doi:10.3762/bjoc.16.94

• University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan Pharmaceutical Sciences at Kagawa Campus, Tokushima Bunri University, 1314-1 Shido, Sanuki, Kagawa 769-2193, Japan 10.3762/bjoc.16.94 Abstract Most heteroaryl selenides and diselenides are biologically active, with

• some reported to act as antioxidants and show activities that are medicinally relevant; hence, the development of efficient methods for their synthesis is an important objective. Herein, a simple method for the synthesis of selenides and diselenides bearing imidazo[1,2-a]pyridine rings and their

• anticancer activity are described. The double C–H selenation of imidazo[1,2-a]pyridine with Se powder was catalyzed by CuI (10 mol %) ligated with 1,10-phenanthroline (10 mol %) at 130 °C under aerobic conditions. The selenides or diselenides were prepared almost selectively using selenium powder in an

Copper-catalyzed O-alkenylation of phosphonates

• Nuria Vázquez-Galiñanes,
• Mariña Andón-Rodríguez,
• Patricia Gómez-Roibás and
• Martín Fañanás-Mastral

Beilstein J. Org. Chem. 2020, 16, 611–615, doi:10.3762/bjoc.16.56

• procedures involving a Mitsunobu reaction between 2-hydroxyalkyl phenyl selenides and phosphonic acid monoesters followed by an oxidation/elimination step [14] or reaction of an enolate with a phosphonic dichloride and subsequent treatment with an alcohol [15] (Scheme 1a). However, these procedures are

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

• rearrangements occurred by a nucleophilic attack of the selenocyanate anion at two different carbon atoms of the seleniranium intermediate. The efficient regioselective synthesis of alkyl, allyl, 2-propynyl, benzyl, 4-fluorobenzyl, and 2-pyridinylmethyl 1,3-thiaselenol-2-ylmethyl selenides was developed based on

• a regio- and stereoselective manner affording 1,3-thiaselenol-2-ylmethyl vinyl selenides in high yields predominantly with Z-configuration. Not a single representative of the 1,3-thiaselenol-2-ylmethyl selenide scaffold has been previously described in the literature. Keywords: 2-(bromomethyl)-1,3

• ][24][25][26][27][28][29]. Among these is an elegant, highly effective approach that led to β-hydroxy, β-mercapto, and β-amino-substituted diorganyl diselenides and selenides. This was accomplished by the opening of three-membered oxygen-, sulfur- and nitrogen-containing heterocycles under the action

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

• , and potassium hydroxide as base in DMSO (Scheme 1). This method has been previously used for the synthesis of symmetrical diaryl selenides from aryl halides [28]. Attempts to use the corresponding 3,3’-dibromo-2,2’-bithiophene as starting material for the synthesis of either DTS 2 with the same

β-Hydroxy sulfides and their syntheses

• Mokgethwa B. Marakalala,
• Edwin M. Mmutlane and
• Henok H. Kinfe

Beilstein J. Org. Chem. 2018, 14, 1668–1692, doi:10.3762/bjoc.14.143

• ranged from 67–92%, with enantioselectivities of 21–73% [41]. In 2009, Sun et al. reported heterobimetallic gallium–titanium variations of the same salen complexes as excellent catalysts for the thiolysis and selenolysis of meso-epoxides, giving the desired β-hydroxy sulfides and selenides in near

• alkenes and their respective applications. Some sulfur-containing natural products. Some natural products incorporating β-hydroxy sulfide moieties. Some synthetic β-hydroxy sulfides of clinical value. Alumina-mediated synthesis of β-hydroxy sulfides, ethers, amines and selenides from epoxides. β-Hydroxy

Transition-metal-free one-pot synthesis of alkynyl selenides from terminal alkynes under aerobic and sustainable conditions

• Adrián A. Heredia and
• Alicia B. Peñéñory

Beilstein J. Org. Chem. 2017, 13, 910–918, doi:10.3762/bjoc.13.92

• Adrian A. Heredia Alicia B. Penenory INFIQC, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA Córdoba, Argentina 10.3762/bjoc.13.92 Abstract Alkynyl selenides were synthesized by a straightforward one-pot and three-step methodology, without the need

• acetylenes. Keywords: alkynyl selenide; electrophilic cyclization; nucleophilic substitution; potassium selenocyanate; terminal alkynes; Introduction Alkynyl selenides, as many other selenium compounds, have potential anti-oxidant activities, and may play a role in certain diseases such as cancer, heart

• diseases, inflammatory processes, arthritis, and skin damage caused by exposure to UV radiation [1][2][3]. However, all these properties belong to organoselenides due to their ability to engage in enzymatic processes [4][5] and alkynyl selenides have demonstrated only limited biological properties [6][7

Ultrasound-promoted organocatalytic enamine–azide [3 + 2] cycloaddition reactions for the synthesis of ((arylselanyl)phenyl-1H-1,2,3-triazol-4-yl)ketones

• Gabriel P. Costa,
• Natália Seus,
• Juliano A. Roehrs,
• Raquel G. Jacob,
• Ricardo F. Schumacher,
• Thiago Barcellos,
• Rafael Luque and
• Diego Alves

Beilstein J. Org. Chem. 2017, 13, 694–702, doi:10.3762/bjoc.13.68

• ] cycloaddition between 1,3-diketones and aryl azidophenyl selenides. These sonochemically promoted reactions were found to be amenable to a range of 1,3-diketones or aryl azidophenyl selenides, providing an efficient access to new ((arylselanyl)phenyl-1H-1,2,3-triazol-4-yl)ketones in good to excellent yields and

• of ((arylselanyl)phenyl-1H-1,2,3-triazol-4-yl)ketones by reacting a range of 1,3-diketones with substituted aryl azidophenyl selenides (Scheme 1). Results and Discussion Due to the fact that organocatalyzed β-enamine–azide cycloaddition reactions between azidophenyl aryl selenides and 1,3-diketones

• evaluated the reactivity of 2,4-pentanedione (2a) with different functionalized aryl azidophenyl selenides 1b–f under identical reaction conditions. Aryl azidophenyl selenides containing either an EDG or an EWG on the aromatic ring delivered the expected selanyltriazoles 3f–i in good isolated yields (Table

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

• ][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

• exclusively the anti-Markovnikov adducts (Scheme 2). On the other hand, vinyl ethers and vinyl selenides (congeners of vinyl sulfides) were found to react with phosphine oxide 1a at 80 °C for about 30 and 20 h, respectively, to deliver difficult-to-separate mixtures of organophosphorus compounds (31P NMR). To

Come-back of phenanthridine and phenanthridinium derivatives in the 21st century

• Lidija-Marija Tumir,
• Marijana Radić Stojković and
• Ivo Piantanida

Beilstein J. Org. Chem. 2014, 10, 2930–2954, doi:10.3762/bjoc.10.312

• to 65% for the second step). Bowman et al. reported a palladium-mediated route using imidoyl-selenides as precursors besides the radical route. Comparison of the cyclisation yields for the same set of phenanthridine derivatives revealed an overall better efficiency of the t-BuO• radical-assisted

• homolytic aromatic substitution of diarylimine (Scheme 3) in respect to the Pd(0)-mediated cyclisation of imidoyl-selenides (Scheme 12) [16]. Authors proposed insertion of a Pd(0) species into the carbon–selenium bond, followed by carbo-palladation onto the phenyl ring. This intermediate then undergoes

Selenium halide-induced bridge formation in [2.2]paracyclophanes

• Laura G. Sarbu,
• Henning Hopf,
• Peter G. Jones and
• Lucian M. Birsa

Beilstein J. Org. Chem. 2014, 10, 2550–2555, doi:10.3762/bjoc.10.266

• halides, selenium electrophiles undergo smooth 1,2-additions to triple bonds, leading to the formation of functionalized vinyl selenides [26]. It has been reported that the addition of electrophilic selenium reagents to alkynes preferably yields the corresponding E-adducts [27]. In continuation of our

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

• Abstract A new, efficient and mild method for the direct oxidation of selenides to selenones using magnesium bis(monoperoxyphthalate) hexahydrate (MMPP) has been developed. Noteworthy this transformation proceeds at room temperature, employs a cheap and safety oxidant and has a broad functional group

• tolerance. Moreover, the produced selenones could be useful intermediates for the synthesis of different heterocyclic compounds. Keywords: heterocycles; monoperoxyphthalate; oxidation; selenides; selenones; Introduction Organoselenium compounds have received considerable attention in recent times because

• efficient and mild methods for their synthesis is of considerable interest. A few previous papers report the synthesis of selenones 2 by oxidation of the corresponding selenides 1 with potassium permanganate [4], trifluoroacetic acid [4] and hydrogen peroxide in trifluoroethanol with stoichiometric amounts

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

• diaryl selenides from triarylbismuthines and diaryl diselenides has been developed. Although the arylation reactions with triarylbismuthines are usually catalyzed by transition-metal complexes, the present arylation of diaryl diselenides with triarylbismuthines proceeds upon photoirradiation in the

• absence of transition-metal catalysts. A variety of unsymmetrical diaryl selenides can be conveniently prepared by using this arylation method. Keywords: arylation; unsymmetrical diaryl selenide; free radical; organobismuth; photoinduced reaction; Introduction A number of organoselenium compounds are

• known to be biologically active [1][2][3][4]. In particular, diaryl selenides are known to have antioxidative effects [5]. Therefore, many studies on the synthetic methods for unsymmetrical diaryl selenides have recently been reported [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23

The chemistry of bisallenes

• Henning Hopf and
• Georgios Markopoulos

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

Alkene selenenylation: A comprehensive analysis of relative reactivities, stereochemistry and asymmetric induction, and their comparisons with sulfenylation

• Vadim A. Soloshonok and
• Donna J. Nelson

Beilstein J. Org. Chem. 2011, 7, 744–758, doi:10.3762/bjoc.7.85

• -chloroalkyl aryl sulfides and selenides, respectively. Conversely, differences between the two reactions have been reported, but the sources of these differences have not been fully explained: While arenesulfenyl chlorides add to alkenes with an anti-Markovnikov orientation, areneselenenyl chlorides add with

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

• previously optimized by our group, compound 25 was efficiently functionalized with an allyl sulfide derived fluorescent probe 26 via CM in aqueous media to demonstrate the utility of functionalization of peptides and proteins by the Mukaiyama aldol reaction (Scheme 10). Allyl selenides are superior

• investigation to allyl selenides, the next element in the group, expecting it to have a similar influence as oxygen and sulfur in metathesis. Se-allylselenocysteine derivative 28a was tested along with the allyl sulfide analogue 27a in model aqueous CM with allyl alcohol under identical reaction conditions. The

• assisted cross-metathesis [17]. b) Putative unproductive chelates for larger ring sizes generated from butenyl or pentenyl sulfides. Functionalization of Mukaiyama aldol product by CM in aqueous media [37]. Comparison of reactivity between allyl sulfides and allyl selenides in aqueous cross-metathesis [38

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

• , hexafluoropropene and alcohols in the presence of KF or CuBr, have been also used for reaction with substituted iodobenzenes (Scheme 27). A variety of perfluoroalkyl- and perfluoroarylcopper mercaptides and selenides have become more accessible, prepared by cleavage of the corresponding disulfides and diselenides

• with copper powder [94]. The resultant RFZCu reagents complexed with DMF or N-methylpyrrolidone, are quite stable and can be stored without decomposition, can be used for the production of aryltrifluoromethyl-, arylpentafluorophenyl sulfides and -selenides from the corresponding iodobenzenes (Scheme 28

• - [147] and tellurophenols [148] under UV irradiation with formation of corresponding perfluoroalkyl sulfides, -selenides and -tellurides. The original method required liquid ammonia as the solvent and Pyrex glassware. Thiophenol and its derivatives containing both, electron-donating and electron

Shelf-stable electrophilic trifluoromethylating reagents: A brief historical perspective

• Norio Shibata,
• Andrej Matsnev and
• Dominique Cahard

Beilstein J. Org. Chem. 2010, 6, No. 65, doi:10.3762/bjoc.6.65

• (or selenides) with m-chloroperbenzoic acid followed by cyclization of the corresponding sulfoxides (or selenoxides) either with triflic anhydride or by direct fluorination with 10% F2/N2 in the presence of one equivalent of triflic acid or HBF4 (Scheme 2). The tellurophenium salt 7 was synthesized in