Synthesis and application of trifluoroethoxy-substituted phthalocyanines and subphthalocyanines

• Satoru Mori and
• Norio Shibata

Beilstein J. Org. Chem. 2017, 13, 2273–2296, doi:10.3762/bjoc.13.224

• environmental burden [61][62]. An unsymmetrical type of TFEO-ZnPc with ethynyl group (4) shows high solubility in Solkane® 365 mfc while a Glaser-type coupling reaction catalyzed by copper with Solkane® 365 mfc as the medium have been reported (Scheme 2) [63]. In this way, TFEO-Pc can be chemically modified in

• ] or trifluoroethoxy (12) [82] group have been reported. These dimers were synthesized from A3B type phthalocyanines containing an ethynyl group and 1,4-bis(azidomethyl)benzene via a so-called “double-click reaction” [83] catalyzed by CuI. The examination of the spectroscopic properties of these dimers

Mechanochemical synthesis of small organic molecules

• Tapas Kumar Achar,
• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

• ]. Mechanochemical Suzuki reaction [56]. Mechanochemical Suzuki–Miyaura coupling by LAG [57]. Mechanochemical Heck reaction [59]. a) Sonogashira coupling under milling conditions. b) The representative example of a double Sonogashira reaction of p-iodoacetophenone with 1,4-bis-ethynyl benzene. Copper-catalyzed CDC

The chemistry and biology of mycolactones

• Matthias Gehringer and
• Karl-Heinz Altmann

Beilstein J. Org. Chem. 2017, 13, 1596–1660, doi:10.3762/bjoc.13.159

Synthesis of novel 13α-estrone derivatives by Sonogashira coupling as potential 17β-HSD1 inhibitors

• Ildikó Bacsa,
• Rebeka Jójárt,
• János Wölfling,
• Gyula Schneider,
• Bianka Edina Herman,
• Mihály Szécsi and
• Erzsébet Mernyák

Beilstein J. Org. Chem. 2017, 13, 1303–1309, doi:10.3762/bjoc.13.126

• -substituted counterpart 15, the olefinic protons are shown as doublets with a large coupling constant of 12.2 Hz, which refers to their trans arrangement. Under the conditions used for the partial saturation, the ethynyl derivatives bearing a phenolic OH group (8c, 10c) furnished benzo[b]furans 12 and 14

Synthesis of alkynyl-substituted camphor derivatives and their use in the preparation of paclitaxel-related compounds

• M. Fernanda N. N. Carvalho,
• Rudolf Herrmann and
• Gabriele Wagner

Beilstein J. Org. Chem. 2017, 13, 1230–1238, doi:10.3762/bjoc.13.122

•  1). As alkyne precursors, phenylacetylene, 1-heptyne, 1-ethynyladamantane, and 1-ethynyl-1-methoxycyclohexane were used. In all cases, mixtures of 12 and 13, together with starting oxoimide 3 and the bis-alkynyl product 4 were obtained. The very slow addition of the acetylide and dilute oxoimide

Correlation of surface pressure and hue of planarizable push–pull chromophores at the air/water interface

• Frederik Neuhaus,
• Fabio Zobi,
• Gerald Brezesinski,
• Marta Dal Molin,
• Stefan Matile and
• Andreas Zumbuehl

Beilstein J. Org. Chem. 2017, 13, 1099–1105, doi:10.3762/bjoc.13.109

• frequencies. The height (h) and the minimum area (A) value of the flipper mechanophore were measured on the basis of the structural parameters of the optimized geometry. These were respectively obtained by: a) measuring the distance between the oxygen and nitrogen atoms of the terminal carboxylic and ethynyl

Interactions between shape-persistent macromolecules as probed by AFM

• Johanna Blass,
• Jessica Brunke,
• Franziska Emmerich,
• Cédric Przybylski,
• Vasil M. Garamus,
• Artem Feoktystov,
• Roland Bennewitz,
• Gerhard Wenz and
• Marcel Albrecht

Beilstein J. Org. Chem. 2017, 13, 938–951, doi:10.3762/bjoc.13.95

• connection of one CD moiety at each phenylene unit. Based on the stiffness of the polymer chain self-passivation of CD polymer modified surfaces is reduced to a minimum. Furthermore, the ethynyl end groups are easily functionalized by click chemistry. Isothermal titration calorimetry (ITC), fluorescence

Nucleophilic and electrophilic cyclization of N-alkyne-substituted pyrrole derivatives: Synthesis of pyrrolopyrazinone, pyrrolotriazinone, and pyrrolooxazinone moieties

• Işıl Yenice,
• Sinan Basceken and
• Metin Balci

Beilstein J. Org. Chem. 2017, 13, 825–834, doi:10.3762/bjoc.13.83

• -methoxyphenyl)ethynyl]-1H-pyrrole-2-carboxylate (7a). To a solution of 1-(bromoethynyl)-4-methoxybenzene (11a, 0.272 g, 1.290 mmol) in freshly distilled anhydrous toluene (20 mL), methyl 1H-pyrrole-2-carboxylate (9, 0.147 g, 1.170 mmol), K3PO4 (0.497 g, 2.340 mmol), CuSO4·5H2O (0.030 g, 0.120 mmol) and 1,10

• , 55.4, 51.6; IR (ATR): 2951, 2257, 1719, 1605, 1543, 1515, 1458, 1438, 1416, 1361, 1334, 1265, 1246, 1179, 1168, 1100, 1069, 1027, 948, 830, 735, 598, 583; HRMS: [M + H]+ calcd for C14H11NO2, 256.09682; found, 256.09730. Methyl 1-[(4-nitrophenyl)ethynyl]-1H-pyrrole-2-carboxylate (7b). To a solution of 1

• C13H11N3O, 226.09749; found, 226.09850. 2-Amino-3-(4-methoxyphenyl)pyrrolo[1,2-a]pyrazin-1(2H)-one (12a). Methyl 1-[(4-methoxyphenyl)ethynyl]-1H-pyrrole-2-carboxylate (7a, 0.080 g, 0.313 mmol) was reacted with hydrazine monohydrate (0,157 g, 3.130 mmol) as described above and the resulting crude mixture was

Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes

• Carmen Moreno-Marrodan,
• Francesca Liguori and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2017, 13, 734–754, doi:10.3762/bjoc.13.73

• progressive decrease of conversion from 99% to 85% was observed after 3 h time on stream, that was partially recovered by treatment with acetone. 1-Bromo-4-ethynylbenzene and 1-ethynyl-4-nitrobenzene The hydrogenations of 7, 1-bromo-4-ethynylbenzene (8) and 1-ethynyl-4-nitrobenzene (9) were also reported with

• in the absence of theoretical or mechanistic studies. Phenylacetylene (7), 1-bromo-4-ethynyl benzene (8) and 1-ethynyl-4-nitrobenzene (9) were hydrogenated using a Pd@C catalyst with trimodal pore-size distribution [152]. The chemoselectivity to the corresponding alkene product showed to follow the

Iodination of carbohydrate-derived 1,2-oxazines to enantiopure 5-iodo-3,6-dihydro-2H-1,2-oxazines and subsequent palladium-catalyzed cross-coupling reactions

• Michal Medvecký,
• Igor Linder,
• Luise Schefzig,
• Hans-Ulrich Reissig and
• Reinhold Zimmer

Beilstein J. Org. Chem. 2016, 12, 2898–2905, doi:10.3762/bjoc.12.289

• furnish the corresponding 5-(trimethylsilyl)ethynyl-substituted 1,2-oxazines syn-5 and anti-5 in good yields (Scheme 3). When these reaction conditions were applied to the D-arabinose-derived 5-iodo-1,2-oxazine anti-4d, the desired coupling product anti-6 was formed merely in 28% yield. Gratifyingly, this

A versatile route to polythiophenes with functional pendant groups using alkyne chemistry

• Xiao Huang,
• Li Yang,
• Rikard Emanuelsson,
• Jonas Bergquist,
• Maria Strømme,
• Martin Sjödin and
• Adolf Gogoll

Beilstein J. Org. Chem. 2016, 12, 2682–2688, doi:10.3762/bjoc.12.265

• , Sweden 10.3762/bjoc.12.265 Abstract A new versatile polythiophene building block, 3-(3,4-ethylenedioxythiophene)prop-1-yne (pyEDOT) (3), is prepared from glycidol in four steps in 28% overall yield. pyEDOT features an ethynyl group on its ethylenedioxy bridge, allowing further functionalization by

• significantly. Prior to the high yielding pyEDOT synthesis presented here, we attempted to synthesize ethynyl-(EDOT) 8 (eEDOT) and ethynyltrimethylsilane-(EDOT) 8’ (etEDOT) with the alkyne moiety directly attached to the ethylenedioxyl bridge, albeit with much lower yield (Scheme 3). The synthesis started from

• was dehalogenated by adding 2 equivalents of n-butyllithium to produce 4-ethynyl-2,2-dimethyl-1,3-dioxolane 6, which was deprotected in acid to give ethynyldiol 7. However, the transetherification of 3,4-dimethoxythiophene to produce 8 turned out to be difficult, with very low yield of only 6%. Thus

Synthesis and characterization of fluorinated azadipyrromethene complexes as acceptors for organic photovoltaics

• Forrest S. Etheridge,
• Roshan J. Fernando,
• Sandra Pejić,
• Matthias Zeller and
• Geneviève Sauvé

Beilstein J. Org. Chem. 2016, 12, 1925–1938, doi:10.3762/bjoc.12.182

• good performance. More work is underway to better understand the mechanism for the enhancement, and will be published separately. Experimental Materials Chalcone (Acros), 4-fluorochalcone (TCI America), 4’-fluorochalcone (TCI America), 4,4’-difluorochalcone (TCI America), 1-ethynyl-4-fluorobenzene

• (Aldrich), 4-ethynyl-α,α,α-trifluorotoluene (Aldrich), n-butyllithium solution (Aldrich), tributyltin chloride (Fisher), tributyl(phenylethynyl)tin (Aldrich), tetrakis(triphenylphosphine)palladium(0) (Aldrich), n-iodosuccinimide (abbreviated NIS, Aldrich) were used as received. All other reagents and

Gold-catalyzed direct alkynylation of tryptophan in peptides using TIPS-EBX

• Gergely L. Tolnai,
• Jonathan P. Brand and
• Jerome Waser

Beilstein J. Org. Chem. 2016, 12, 745–749, doi:10.3762/bjoc.12.74

• is highly attractive, but the use of a carbon linker is usually required. Herein, we report the gold-catalyzed direct alkynylation of tryptophan in peptides using the hypervalent iodine reagent TIPS-EBX (1-[(triisopropylsilyl)ethynyl]-1,2-benziodoxol-3(1H)-one). The reaction proceeded in 50–78% yield

• the Sonogashira reaction, which requires modified non-natural amino acids [32][33]. In 2013, our group reported the alkynylation of thiols using the hypervalent iodine reagent TIPS-EBX (1a, 1-[(triisopropylsilyl)ethynyl]-1,2-benziodoxol-3(1H)-one) (Scheme 1A) [34]. The reaction was almost

Creating molecular macrocycles for anion recognition

• Amar H. Flood

Beilstein J. Org. Chem. 2016, 12, 611–627, doi:10.3762/bjoc.12.60

• the CH groups in pyridine that poke uncomfortably into neighboring ligands. The coordination chemistry taught us that triazoles are sterically small, perhaps small enough to be as innocent as ethynyl units (e.g., Figure 4d and overlay in Figure 4e). If that idea was true, then triazoles became prime

Hydroquinone–pyrrole dyads with varied linkers

• Hao Huang,
• Christoffer Karlsson,
• Maria Strømme,
• Martin Sjödin and
• Adolf Gogoll

Beilstein J. Org. Chem. 2016, 12, 89–96, doi:10.3762/bjoc.12.10

• in their study, ten equivalents of styrene were used to obtain 28% yield, indicating that the reaction conditions were not optimal, and therefore cannot be applied to other vinyl substrates such as dimethoxystyrene directly. A synthetic route via hydrogenation of the ethynyl linker compound 4d was

• material for the corresponding phosphonate. However, neither n-BuLi nor t-BuOK used as base succeeded to give the desired product. Acetylene linker: Synthesis of 3-((2,5-dimethoxyphenyl)ethynyl)-1H-pyrrole (3d) The synthesis strategy for the ethynyl-linked compound 3d was straightforward, using a

• Sonogashira coupling reaction (Scheme 3). Thus, 2,5-dimethoxyphenyl bromide (8) was converted to ((2,5-dimethoxyphenyl)ethynyl)trimethylsilane (9), which was desilylated by addition of NaOH (aq) to give 2-ethynyl-1,4-dimethoxybenzene (10). Sonogashira conditions were as described by Erdélyi et al. using

Recent advances in metathesis-derived polymers containing transition metals in the side chain

• Ileana Dragutan,
• Valerian Dragutan,
• Bogdan C. Simionescu,
• Albert Demonceau and
• Helmut Fischer

Beilstein J. Org. Chem. 2015, 11, 2747–2762, doi:10.3762/bjoc.11.296

• containing an enamine-cobalticenium group (16) was first prepared by hydroamination of the ethynyl cobalticenium with n-butylamine-substituted norbornene 15. Next, 16 was polymerized to 17, by ROMP under mild conditions (Scheme 7A). In the second approach, first, the monomer 14 was polymerized to 17a

• , followed by functionalization of the latter with n-butylamine to yield 17b, and finally this organic polymer hydroaminated the ethynyl cobalticenium to produce 17 (Scheme 7B). Both protocols embody an elegant and original ROMP-based access to cobalticenium-containing polyelectrolytes. Ruthenium-, iridium

Synthesis of bi- and bis-1,2,3-triazoles by copper-catalyzed Huisgen cycloaddition: A family of valuable products by click chemistry

• Zhan-Jiang Zheng,
• Ding Wang,
• Zheng Xu and
• Li-Wen Xu

Beilstein J. Org. Chem. 2015, 11, 2557–2576, doi:10.3762/bjoc.11.276

• -workers performed the CuAAC reaction of 1,1’-diazidoferrocene with ethynyl [5]-helicenequinone [23], and found the open chain bistriazolylphenyl-helicenequinone 17 could be obtained in good yield when CuSO4/sodium ascorbate was used in THF/H2O (Scheme 7). However, the cyclic 5,5'-bitriazole 18 was

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

• , giving rise to the Z-stereoisomer of 2d in 47% and 68% yields, respectively. At this stage we decided to explore two simple variations of the groups directly connected to the ethynyl moiety, that are, a cyclopropyl group and the bulky tert-butyl group. Thus, we reacted cyclopropylethynyl(phenyl)sulfane

• always be detected (and not removed) from the desired product 2f. We were also interested in exploring the electronic effects of para-substitution of the phenyl group directly attached to the ethynyl moiety on the reaction outcome; thus we selected compounds 1g–j and reacted them under our

• the reaction from occurring. Conversely, and as expected, the 4-nitro group had a detrimental effect on the reaction outcome. When 4-nitrophenyl(ethynyl)sulfane (1i) was treated with TiF4, it took nearly 7 days to observe some reaction progress, and the desired Z-isomer of 2i could be isolated in only

Asymmetric 1,4-bis(ethynyl)bicyclo[2.2.2]octane rotators via monocarbinol functionalization. Ready access to polyrotors

• Cyprien Lemouchi and
• Patrick Batail

Beilstein J. Org. Chem. 2015, 11, 1881–1885, doi:10.3762/bjoc.11.202

• Cyprien Lemouchi Patrick Batail Laboratoire MOLTECH-Anjou, Université d’Angers, CNRS UMR 6502, 2 Boulevard Lavoisier, 49045 Angers, France 10.3762/bjoc.11.202 Abstract Asymmetric rotators with a 1,4-bis(ethynyl)bicyclo[2.2.2]octane (BCO) core are needed for engineering crystalline arrays of

• -bis(ethynyl)bicyclo[2.2.2]octane (BCO) rotator core have included the design of ultra-fast rotors [6][7][8], the evocation of the phenomena of quantum dissipation in a hybrid system of BCO and organic conductors [9], and the discovery of a correlated motion in cogwheel pairs of BCO rotators [10], that

• symmetric precursors and targets. We disclose in this paper an efficient route that provides a general entry into asymmetric 1,4-bis(ethynyl)bicyclo[2.2.2]octane (BCO) rotators. The importance of this synthetic advance is illustrated by three examples demonstrating the ready accessibility to an even larger

Synthesis and spectroscopic properties of β-triazoloporphyrin–xanthone dyads

• Dileep Kumar Singh and
• Mahendra Nath

Beilstein J. Org. Chem. 2015, 11, 1434–1440, doi:10.3762/bjoc.11.155

• ), 3-ethynyl-6-nitroxanthen-9-one (4), and 3-ethynyl-6-methoxyxanthen-9-one (5) were synthesized by using the literature procedures [39][40][47][48][49]. In addition, copper(II) 2-azido-5,10,15,20-tetraphenylporphyrin (1) [50] was synthesized in good yield after the treatment of copper(II) 2-amino

• -5,10,15,20-tetraphenylporphyrin (1) or zinc(II) 2-azidomethyl-5,10,15,20-tetraphenylporphyrin (2) with ethynyl-substituted xanthones 3, 4 or 5, using copper sulfate and ascorbic acid in DMF at 80 °C (Scheme 1). Further, the demetalation of the copper(II) porphyrins 6a,d,g with conc. H2SO4 at 0 °C and zinc(II

• 602 and 651 nm). In contrast, the copper porphyrins did not show any significant emission due to the paramagnetic nature of the Cu(II) ions [56]. Conclusion In summary, we have successfully synthesized and characterized two new alkyne-substituted xanthones, 3-ethynyl-6-nitroxanthen-9-one and 3,6

Cross-metathesis reaction of α- and β-vinyl C-glycosides with alkenes

• Ivan Šnajdr,
• Kamil Parkan,
• Filip Hessler and
• Martin Kotora

Beilstein J. Org. Chem. 2015, 11, 1392–1397, doi:10.3762/bjoc.11.150

• reports regarding synthesis of vinyl C-deoxyribosides have been published so far. Among them is the Lindlar catalyst mediated hydrogenation of ethynyl β-C-deoxyriboside (prepared by a rather lengthy synthetic procedure) that provided vinyl β-C-deoxyribofuranosides [9]. Another procedure leading to pure

• preparation of vinyl α-C-deoxyriboside α-2 and β-C-deoxyriboside β-2 seems the reaction of a halogenose with ethynylmagnesium chloride followed by hydrogenation, this approach has not been reported yet (to the best of our knowledge). Presumably, difficulties regarding separation of a mixture of ethynyl α-C

• -deoxyriboside α-1 and β-C-deoxyriboside β-1 precluded any attempts. Notwithstanding this, we decided to test this approach. We found that hydrogenation of the epimeric mixture of ethynyl α-C-deoxyriboside α-1 and β-C-deoxyriboside β-1 on Lindlar catalyst at 1 atm of H2 provided, as expected, a mixture of the

Interactions between tetrathiafulvalene units in dimeric structures – the influence of cyclic cores

• Huixin Jiang,
• Virginia Mazzanti,
• Christian R. Parker,
• Søren Lindbæk Broman,
• Jens Heide Wallberg,
• Karol Lušpai,
• Adam Brincko,
• Henrik G. Kjaergaard,
• Anders Kadziola,
• Peter Rapta,
• Ole Hammerich and
• Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2015, 11, 930–948, doi:10.3762/bjoc.11.104

• missing); HRMS (MALDI+, FT-ICR, dithranol): m/z = 1192.24515 [M•+] (calcd for C56H80S12Si2+: 1192.24415). Compound 7. A flask containing Pd(PPh3)4 (11 mg, 0.01 mmol), 2,6-bis(ethynyl)pyridine (6.3 mg, 0.05 mmol), and CuI (1 mg, 0.01 mmol) was charged with an argon balloon. A solution of 9 (50 mg, 0.01

Mechanical stability of bivalent transition metal complexes analyzed by single-molecule force spectroscopy

• Manuel Gensler,
• Christian Eidamshaus,
• Maurice Taszarek,
• Hans-Ulrich Reissig and
• Jürgen P. Rabe

Beilstein J. Org. Chem. 2015, 11, 817–827, doi:10.3762/bjoc.11.91

• }butan-1-ol (4): A suspension of 4-{[2-(pyridin-3-yl)ethynyl]pyridin-5-yl}but-3-yn-1-ol (3) [27] (45 mg, 0.18 mmol) and Pd/C (45 mg, 100 wt %) in MeOH (3 mL) was stirred under an atmosphere of hydrogen (balloon) for 3 h until complete consumption of the starting material (by TLC). The mixture was

Self-assembly of heteroleptic dinuclear metallosupramolecular kites from multivalent ligands via social self-sorting

• Christian Benkhäuser and
• Arne Lützen

Beilstein J. Org. Chem. 2015, 11, 693–700, doi:10.3762/bjoc.11.79

• -{(trimethylsilyl)ethynyl}pyridine (7) [27], 5-{(trimethylsilyl)ethynyl}-2,2'-bipyridine (10) [28], and 5-ethynyl-2,2'-bipyridine (11) [28] were prepared according to literature known procedures. (rac)-6H,16H-5,15-Methanodi-1N,10N,11N,20N-phenanthro[5’,6’-b,5’’,6’’-f][1,5]diazocine ((rac)-1): 5-Aminophenanthroline

• -bottomed flask was charged with 5-ethynyl-2,2’-bipyridine (11, 109 mg, 0.6 mmol, 2 equiv), 1,3-diiodobenzene (100 mg, 0.3 mmol), [Pd(PPh3)2Cl2] (5.32 mg, 2.5 mol %), and copper(I) iodide (1.44 mg, 2.5 mol %) and flushed with argon. Dry THF (15 mL) and dry piperidine (5 mL) were added and the resulting

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

• substitution at the boron has less influence on the spectroscopic properties of the dyes [42]. So far, major endeavors have been dedicated to the preparation of classical F-BODIPY structures and less common E-BODIPY (E for ethynyl) and the examination of their spectroscopic and salient physical properties [43

• ethynyl tetra(ethylene glycol)methyl groups [58][59]. Synthesis of the BODIPY precursors The synthesis of the tris-iodo functionalized BODIPY dyes and their acetylenic derivatives is sketched in Scheme 1. The synthesis of derivatives 7 and 8 have previously been reported using a regioselective iodination

• 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