Rapid pseudo five-component synthesis of intensively blue luminescent 2,5-di(hetero)arylfurans via a Sonogashira–Glaser cyclization sequence

• Fabian Klukas,
• Alexander Grunwald,
• Franziska Menschel and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2014, 10, 672–679, doi:10.3762/bjoc.10.60

• . 2,5-dihalogenated furans can be in principle employed in cross-coupling reactions, however, the poor stability of these dihalogenated precursors renders this approach very tedious [29]. Recent publications report gold-catalyzed syntheses of di(hetero)arylfurans starting from arylbutadiynes [30][31

• ]. However, the major drawback of this approach is the complex, time-consuming preparation of the complicated gold catalyst and the separate synthesis of the butadiyne substrates. In a similar study arylbutadiynes prepared by Glaser homocoupling were converted into symmetrical 2,5-di(hetero)arylfurans [32

Silver and gold-catalyzed multicomponent reactions

• Giorgio Abbiati and
• Elisabetta Rossi

Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46

• Giorgio Abbiati Elisabetta Rossi Dipartimento di Scienze Farmaceutiche, Sezione di Chimica Generale e Organica “A. Marchesini”, Università degli Studi di Milano, Via Venezian, 21 – 20133 Milano, Italy 10.3762/bjoc.10.46 Abstract Silver and gold salts and complexes mainly act as soft and

• carbophilic Lewis acids even if their use as σ-activators has been rarely reported. Recently, transformations involving Au(I)/Au(III)-redox catalytic systems have been reported in the literature. In this review we highlight all these aspects of silver and gold-mediated processes and their application in

• multicomponent reactions. Keywords: A3-coupling; gold; multicomponent reactions; silver; Introduction Coinage metals (copper, silver and gold) are extensively used in the homogenous catalysis of organic reactions. Similarities and differences in the catalytic activity of these elements have been recently

Aminofluorination of 2-alkynylanilines: a Au-catalyzed entry to fluorinated indoles

• Antonio Arcadi,
• Emanuela Pietropaolo,
• Antonello Alvino and
• Véronique Michelet

Beilstein J. Org. Chem. 2014, 10, 449–458, doi:10.3762/bjoc.10.42

• Paris, UMR 8247, Ecole Nationale Supérieure de Chimie de Paris, Chimie ParisTech, 11 rue P. et M. Curie, F-75231 Paris Cedex 05, France 10.3762/bjoc.10.42 Abstract The scope and limitations of gold-catalyzed tandem cycloisomerization/fluorination reactions of unprotected 2-alkynylanilines to have

• access to 3,3-difluoro-2-aryl-3H-indoles and 3-fluoro-2-arylindoles are described. An unprecedented aminoauration/oxidation/fluorination cascade reaction of 2-alkynylanilines bearing a linear alkyl group on the terminal triple bond is reported. Keywords: 2-alkynylanilines; fluorination; gold catalysis

• and alkynyl phenylhydrazones, respectively. Propargyl amidines were converted into 5-fluoromethylimidazoles in the presence of Selectfluor under gold(I) catalysis [34][35][36] through a cascade cyclization/fluorination process [37]. Following our previous work on gold catalysts (Scheme 1) [38], we

Synthesis of new enantiopure poly(hydroxy)aminooxepanes as building blocks for multivalent carbohydrate mimetics

• Léa Bouché,
• Maja Kandziora and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2014, 10, 213–223, doi:10.3762/bjoc.10.17

• stereocontrol and the flexibility concerning the chain length. In 2005, Al-Harrasi synthesized the first tert-butyldimethylsilyl (TBS)-protected aminopyrans (n = 0) and aminooxepanes (n = 1) via this reaction route [23]. Several of the poly(hydroxy)aminopyrans [24] were connected to gold nanoparticles and the

Recent applications of the divinylcyclopropane–cycloheptadiene rearrangement in organic synthesis

• Sebastian Krüger and
• Tanja Gaich

Beilstein J. Org. Chem. 2014, 10, 163–193, doi:10.3762/bjoc.10.14

• schisanwilsonene A (126, see Scheme 15), isolated from Schisandra wilsoniana [111], a plant used in traditional chinese medicine. Submission of 1,6-enyne 116 to cationic gold-catalyst 117 led to 5-exo-dig cyclization and intermediate formation of bridged bicycle 119. Subsequent 1,5-acyl-shift afforded

• as the corresponding bis-zinc-enolate species. DVCPR occurred at ambient temperature, final acidic workup provided cycloheptadione 247 in excellent yield (see Scheme 31). Toste and coworkers [203] reported a tandem gold-catalyzed Claisen rearrangement from popargyl vinyl ether 248 (see Scheme 32) to

• . Toste and coworkers [205] discovered a 1,2-pivaloyl shift and cyclopropanation of the resulting gold-carbenoid from 258 with enyne 259 to yield vinylalkynecyclopropane 260. This compound was shown to undergo a gold catalyzed DVCPR to yield 261. Note that this reaction does most likely proceed via a step

Charge-transfer interaction mediated organogels from 18β-glycyrrhetinic acid appended pyrene

• Jun Hu,
• Jindan Wu,
• Qian Wang and
• Yong Ju

Beilstein J. Org. Chem. 2013, 9, 2877–2885, doi:10.3762/bjoc.9.324

• micrographs are prepared by cutting a piece of gel and putting it on the surface of a glass plate to dry at room temperature. Samples for SEM are prepared by flash freezing in liquid nitrogen followed by lyophilisation, and the freeze-dried sample was placed on a silica surface to be coated by gold before the

The renaissance of organic radical chemistry – deja vu all over again

• Corey R. J. Stephenson,
• Armido Studer and
• Dennis P. Curran

Beilstein J. Org. Chem. 2013, 9, 2778–2780, doi:10.3762/bjoc.9.312

• homolytic aromatic substitution (BHAS) [3], b) photoredox catalysis [4][5][6][7][8], c) redox chemistry using Bu4NI in combination with t-BuOOH [9], d) transition metal catalyzed processes where radicals are suggested to interact directly with copper, nickel, zinc, palladium, gold and so on [10][11][12][13

One-pot cross-enyne metathesis (CEYM)–Diels–Alder reaction of gem-difluoropropargylic alkynes

• Santos Fustero,
• Paula Bello,
• Javier Miró,
• María Sánchez-Roselló,
• Günter Haufe and
• Carlos del Pozo

Beilstein J. Org. Chem. 2013, 9, 2688–2695, doi:10.3762/bjoc.9.305

• reactions for the preparation of different difluoropropargylamides and ketones, having been subjected to intramolecular hydroaminations [23], cascade RCEYM–Diels–Alder reactions [24], [2 + 2 + 2] cycloadditions and gold-mediated dimerization reactions [25]. Although the CEYM reaction has been found to be

Gold(I)-catalyzed domino cyclization for the synthesis of polyaromatic heterocycles

• Mathieu Morin,
• Patrick Levesque and
• Louis Barriault

Beilstein J. Org. Chem. 2013, 9, 2625–2628, doi:10.3762/bjoc.9.297

• Mathieu Morin Patrick Levesque Louis Barriault Center for Catalysis Research and Innovation, Department of Chemistry, University of Ottawa, Ottawa, Canada K1T 1B5 10.3762/bjoc.9.297 Abstract Gold(I) complexes have emerged as powerful and useful catalysts for the formation of new C–C, C–O and C–N

• ; cyclization; gold(I); gold catalysis; heterocycles; regioselectivity; Introduction In the last decade, phosphino and NHC–gold complexes have become prominent catalysts for the addition of nucleophiles to alkenes, alkynes and allenes [1][2][3][4][5][6][7][8][9][10][11]. Owing to the high affinity of gold(I

• ) complexes to C–C π-systems in the presence of other functional groups combined by its predictable reactivity pattern, the gold(I)-catalyzed reaction provides tremendous opportunities for the discovery of new and useful reactions [12]. Recently, we [13] and other groups [14][15][16][17] reported that

New developments in gold-catalyzed manipulation of inactivated alkenes

• Michel Chiarucci and
• Marco Bandini

Beilstein J. Org. Chem. 2013, 9, 2586–2614, doi:10.3762/bjoc.9.294

• intends to summarize the recent progresses in the field, with particular emphasis on mechanistic details. Keywords: alkene; gold catalysis; mechanism; organic synthesis; Review 1 Introduction Homogeneous gold catalysis is emerged as one of the most powerful means for the activation of C–C multiple bonds

• toward a number of complexity-oriented transformations. In this segment, gold-catalyzed addition of carbon- and heteroatom-based nucleophiles to inactivated alkenes are widely recognized as “capricious” transformations due to alkyne and allene counterparts [1][2][3][4][5]. However, over the past few

• years, tremendous developments were made, and some of the major contributes will be summarized in the present review. Mechanistically, it is generally accepted that the gold-catalyzed nucleophilic addition to alkenes proceeds through three elementary steps: i) activation of the C–C double bond by gold

Stereodivergent synthesis of jaspine B and its isomers using a carbohydrate-derived alkoxyallene as C₃-building block

• Volker M. Schmiedel,
• Stefano Stefani and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2013, 9, 2564–2569, doi:10.3762/bjoc.9.291

• therefore leads to a stereodivergent approach to the natural product and its enantiomer. The gold-catalyzed 5-endo-cyclization affords the corresponding dihydrofurans, which after separation, azidation of the enol ether moiety and two subsequent reduction steps give the natural product and its stereoisomers

• . Keywords: chiral auxiliaries; gold catalysis; jaspine B; lithiated alkoxyallenes; natural product synthesis; pachastrissamine; tetrahydrofurans; Introduction Jaspine B, also known as pachastrissamine (1, Scheme 1), is an anhydrophytosphingosine derivative, isolated 2002 from the marine sponge Pachastrissa

• cyclization of 7 gave a higher yield than the attempted gold(I) catalysis (39% overall yield), which might be due to the deactivation of the gold catalyst by impurities still present in the crude allenyl alcohol 7. Next, several methods for the introduction of the amino group were examined. We were very

Ambient gold-catalyzed O-vinylation of cyclic 1,3-diketone: A vinyl ether synthesis

• Yumeng Xi,
• Boliang Dong and
• Xiaodong Shi

Beilstein J. Org. Chem. 2013, 9, 2537–2543, doi:10.3762/bjoc.9.288

• Yumeng Xi Boliang Dong Xiaodong Shi C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States 10.3762/bjoc.9.288 Abstract Gold-catalyzed O-vinylation of cyclic 1,3-diketones has been achieved for the first time, which provides direct

• access to various vinyl ethers. A catalytic amount of copper triflate was identified as the significant additive in promoting this transformation. Both aromatic and aliphatic alkynes are suitable substrates with good to excellent yields. Keywords: alkyne; copper salt; diketone; gold catalysis; vinyl

• ether; Introduction The past decade has witnessed the fast growth of homogeneous gold catalysis as one of the important branches in transition-metal chemistry [1][2][3][4][5][6][7][8][9]. The utility of cationic gold(I) complexes as π-carbophilic acids toward alkyne and allene activation renders them

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

• : asymmetric catalysis; DFT; 1,3-dipolar cycloaddition; gold catalysis; NICS; NTR; oxazolones; prolines; Introduction The synthesis of α-amino acids employing an α-amino carbonyl template constitutes the most straightforward route to introduce the α-side chain [1]. As a valid example, oxazol-5-(4H)-ones

• base (Figure 1) [18][19]. This catalytic system was very effective but the reactions performed with (R)-Binap(AuOBz)2 (Figure 1) as catalyst offered a very low enantioselection, for example, a 8% ee was achieved in the 1,3-DC of alanine derived azlactone and N-phenylmaleimide (NPM). Numerous gold

• -catalyzed transformations employing mild reaction conditions appeared during the last twelve years [20][21][22]. Initially, coordination arrangements of chiral gold complexes avoided high enantiodiscriminations but, recently, it has been demonstrated that chiral bis-gold complexes type 2 (Figure 1) are very

Crystal design using multipolar electrostatic interactions: A concept study for organic electronics

• Peer Kirsch,
• Qiong Tong and
• Harald Untenecker

Beilstein J. Org. Chem. 2013, 9, 2367–2373, doi:10.3762/bjoc.9.272

• the HOMO and LUMO energy levels, which have to be consistent with the work function of electrode materials used in OFETs – typically gold with a work function of around −5.4 eV. Taking this into account, the semifluorinated tetraoxatetrahydrohexacene 1 was selected as synthetic target for our concept

Gold(I)-catalyzed enantioselective cycloaddition reactions

• Fernando López and
• José L. Mascareñas

Beilstein J. Org. Chem. 2013, 9, 2250–2264, doi:10.3762/bjoc.9.264

• Investigación en Química Biolóxica e Materiais Moleculares (CIQUS). Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain 10.3762/bjoc.9.264 Abstract In recent years there have been extraordinary developments of gold(I)-catalyzed enantioselective processes. This includes progress in the

• processes. Keywords: alkyne; allene; asymmetric catalysis; cycloaddition; enantioselective; gold; gold catalysis; Introduction In the past decade, there have been extraordinary advances in the development of novel stereoselective gold(I)-catalyzed transformations [1][2][3][4][5][6][7][8][9][10]. In this

• context, enantioselective gold catalysis has been identified as a particularly challenging goal because the linear two-coordination mode of gold(I) complexes and the out-sphere π-activation usually associated to carbophilic gold catalysts [11] places ligands far from the reacting centers, thus limiting

Gold(I)-catalyzed 6-endo hydroxycyclization of 7-substituted-1,6-enynes

• Ana M. Sanjuán,
• Alberto Martínez,
• Patricia García-García,
• Manuel A. Fernández-Rodríguez and
• Roberto Sanz

Beilstein J. Org. Chem. 2013, 9, 2242–2249, doi:10.3762/bjoc.9.263

• )-3-(methylbut-2-enyl)benzenes, 1,6-enynes having a condensed aromatic ring at C3–C4 positions, has been studied under the catalysis of cationic gold(I) complexes. The selective 6-endo-dig mode of cyclization observed for the 7-substituted substrates in the presence of water or methanol giving rise to

• hydroxy(methoxy)-functionalized dihydronaphthalene derivatives is highly remarkable in the context of the observed reaction pathways for the cycloisomerizations of 1,6-enynes bearing a trisubstituted olefin. Keywords: catalysis; dihydronaphthalenes; gold; gold catalysis; hydroxycyclization; selectivity

• ; Introduction The cycloisomerization reactions of enynes catalyzed by gold complexes are a powerful tool for accessing complex products from rather simple starting materials under soft and straightforward conditions [1][2][3][4]. In this context, 1,6-enynes have been extensively studied, mainly by Echavarren

Synthesis of axially chiral gold complexes and their applications in asymmetric catalyses

• Yin-wei Sun,
• Qin Xu and
• Min Shi

Beilstein J. Org. Chem. 2013, 9, 2224–2232, doi:10.3762/bjoc.9.261

• were also successfully synthesized and characterized by X-ray crystal diffraction. A weak gold-π interaction between the Au atom and the aromatic ring in these gold complexes was identified. Furthermore, we confirmed the formation of a pair of diastereomeric isomers in NHC gold complexes bearing an

• product in moderate yields and up to 29% ee. Keywords: asymmetric gold catalysis; chiral Au catalysts; gold-π interaction; NHC gold complex; Introduction After the long-held assumption of the non-reactivity of gold complexes, numerous reactions catalyzed by gold complexes have emerged in the last 2

• decades [1][2][3][4][5][6][7][8][9]. In the past few years, reports on gold-catalyzed organic transformations have increased substantially [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. Homogeneous gold catalysis has proven to be a powerful tool in organic synthesis

Synthesis, characterization and luminescence studies of gold(I)–NHC amide complexes

• Adrián Gómez-Suárez,
• David J. Nelson,
• David G. Thompson,
• David B. Cordes,
• Duncan Graham,
• Alexandra M. Z. Slawin and
• Steven P. Nolan

Beilstein J. Org. Chem. 2013, 9, 2216–2223, doi:10.3762/bjoc.9.260

• Nanometrology, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK 10.3762/bjoc.9.260 Abstract A flexible, efficient and straightforward methodology for the synthesis of N-heterocyclic carbene gold(I)–amide complexes is reported. Reaction of the versatile building block [Au(OH)(IPr)] (1) (IPr

• fluorescence measurements have allowed the identification of their excitation and emission wavelengths (λmax). These studies revealed that by selecting the appropriate amine ligand the emission can be easily tuned to achieve a variety of colors, from violet to green. Keywords: fluorescence; gold; gold

• catalysts in gold-catalyzed processes [1][2][3][4][5][6][7]. This has led several research groups to investigate general, green and straightforward methodologies for the synthesis of organogold complexes. We have focused on the synthesis and study of transition metal complexes bearing N-heterocyclic carbene

Gold-catalyzed glycosidation for the synthesis of trisaccharides by applying the armed–disarmed strategy

• Abhijeet K. Kayastha and
• Srinivas Hotha

Beilstein J. Org. Chem. 2013, 9, 2147–2155, doi:10.3762/bjoc.9.252

• oligosaccharides. The gold catalysis for glycosidation reactions, in which alkynylated glycosides are used, has emerged as one of the versatile options in this regard. A cleavage of the interglycosidic bond that was thought to be due to the higher reaction temperature and the acidic medium was observed during the

• moiety were screened. It was found that 1-ethynylcyclohexanyl (Ech) glycosides are suitable for carrying out the glycosidation at 25 °C in the presence of 5 mol % each of AuCl3 and AgSbF6. Subsequently, Ech-glycosides were observed to be suitable for the synthesis of trisaccharides under gold catalysis

• conditions. Keywords: alkynes; armed–disarmed effect; glycosidation; gold; Introduction Observations that gold(III) has a great affinity for alkynes placed the chemistry of gold in an enviable situation that culminated into the total synthesis of several natural products, in which gold-mediated reactions

Gold(I)-catalyzed hydroarylation reaction of aryl (3-iodoprop-2-yn-1-yl) ethers: synthesis of 3-iodo-2H-chromene derivatives

• Pablo Morán-Poladura,
• Eduardo Rubio and
• José M. González

Beilstein J. Org. Chem. 2013, 9, 2120–2128, doi:10.3762/bjoc.9.249

• hydroarylation steps. Keywords: alkyne; chromene; gold; gold catalysis; hydroarylation; iodine; Introduction The structure of 2H-chromene embodies a relevant heterocyclic motif, which is present in naturally occurring compounds [1][2][3][4][5][6] and encodes interesting properties that renders it attractive

• recognized as suitable catalysts to convert aryl propargyl ethers into chromenes. Nowadays, alternative gold(I)-based catalysts have been successfully exploited to further prepare substituted 2H-chromenes [34][35][36][37][38], as well as a wide variety of relevant heterocyclic compounds [39][40]. On the

• other hand, migratory cycloisomerization are important processes in contemporary catalysis [41]. In this context, our group is interested in C–H functionalization reactions of arenes involving propargylic derivatives [42]. Furthermore, the influence of different gold(I) catalysts over the outcome of the

Post-Ugi gold-catalyzed diastereoselective domino cyclization for the synthesis of diversely substituted spiroindolines

• Amit Kumar,
• Dipak D. Vachhani,
• Sachin G. Modha,
• Sunil K. Sharma,
• Virinder S. Parmar and
• Erik V. Van der Eycken

Beilstein J. Org. Chem. 2013, 9, 2097–2102, doi:10.3762/bjoc.9.246

• adducts which are subjected to a cationic gold-catalyzed diastereoselective domino cyclization to furnish diversely substituted spiroindolines. All the reactions run via an exo-dig attack in the hydroarylation step followed by an intramolecular diastereoselective trapping of the imminium ion. The whole

• sequence is atom economic and the application of a multicomponent reaction assures diversity. Keywords: alkynes; gold; indoles; multicomponent; spiroindolines; Ugi; Introduction The importance of nitrogen containing heterocyclic molecules in chemical biology is undisputed. The synthesis of such

• efficient activator of alkynes, gold has recently attracted a lot of attention [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]. Many tandem approaches have been reported which utilize this coinage metal for the construction of variously substituted complex molecules [37][38

Total synthesis of (−)-epimyrtine by a gold-catalyzed hydroamination approach

• Thi Thanh Huyen Trinh,
• Khanh Hung Nguyen,
• Patricia de Aguiar Amaral and
• Nicolas Gouault

Beilstein J. Org. Chem. 2013, 9, 2042–2047, doi:10.3762/bjoc.9.242

• -alanine. The key step to access the enantiopure pyridone intermediate was achieved by a gold-mediated cyclization. Finally, various transformations afforded the natural product in a few steps and good overall yield. Keywords: epimyrtine; gold; gold catalysis; heterocycles; hydroamination; quinolizidine

• stereoselective synthetic routes are still being sought after. In the past decades, gold catalysis has emerged as an important tool in a plethora of fields of synthetic organic chemistry, and after methodological investigations [11][12][13][14][15][16], the good functional group compatibility of gold catalysts

• renders gold catalysis a straightforward protocol in the realm of the synthesis of natural products [17][18]. Herein we report a short total synthesis of (−)-epimyrtine employing an alternative strategy by using a gold(I)-catalyzed hydroamination of a β-aminoynone as the key step. Actually, cyclization of

Gold catalysis for organic synthesis II

• F. Dean Toste

Beilstein J. Org. Chem. 2013, 9, 2040–2041, doi:10.3762/bjoc.9.241

• F. Dean Toste Department of Chemistry, University of California, Bekeley, CA, USA 10.3762/bjoc.9.241 Keywords: gold catalysis; Two years have now passed since the publication of the first Thematic Series on gold catalysis for organic synthesis in the Beilstein Journal of Organic Chemistry. In

• the intervening time, the pace of progress and discovery in the field has continued unabated. Many of these advancements are exemplified in the more than twenty contributions that have been collected in this second Thematic Series. Many of the early examples of homogeneous gold-catalysis focused on

• the ability of cationic gold complexes to activate π-bonds towards attack of nucleophiles. This reactivity platform, examples of which can be found in this Thematic Series, continues to provide a fruitful basis for the discovery of important new transformations. This includes the development of a

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

• ; gold; gold catalysis; hydrophenoxylation; silver-free; single component; solvent-free; Introduction The use of gold compounds to promote hydroelementation reactions has grown tremendously over the past few years [1][2][3][4][5]. Using this approach, a host of different organic substrates have been

• development of sustainable transformations [6][7][8][9][10] that are practical and operationally straightforward, we decided to attempt to generate the active gold species in situ from a single-component precursor. Furthermore, one of the current goals of developing sustainable and “greener” organic reactions

• is focused on the elimination of solvents and additives from the synthetic methodology [10]. Thus, the design of gold catalyzed reactions that proceed under solvent-free conditions and without the addition of silver salts or acidic promoters would be of interest to those charged with designing

Gold-catalyzed reaction of oxabicyclic alkenes with electron-deficient terminal alkynes to produce acrylate derivatives

• Yin-wei Sun,
• Qin Xu and
• Min Shi

Beilstein J. Org. Chem. 2013, 9, 1969–1976, doi:10.3762/bjoc.9.233

• Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, People’s Republic of China 10.3762/bjoc.9.233 Abstract Oxabicyclic alkenes can react with electron-deficient terminal alkynes in the presence of a gold catalyst under mild conditions

• reactions is also discussed. Keywords: gold catalysis; oxabicyclic alkenes; substituted acrylates; Introduction Oxabicyclic alkenes are common intermediates in organic synthesis since these compounds can be easily prepared and have a high reactivity for further transformations [1][2][3][4][5][6][7][8

• ]. For example, they are often used to construct substituted tetrahydronaphthalene skeletons in the presence of metal catalysts such as Pd [9][10], Ir [11][12][13][14][15], Rh [16][17][18][19][20][21] and Cu [22]. However, their reactivity in the presence of gold catalysts has been rarely reported [23