Efficient syntheses of climate relevant isoprene nitrates and (1R,5S)-(−)-myrtenol nitrate

• Sean P. Bew,
• Glyn D. Hiatt-Gipson,
• Graham P. Mills and
• Claire E. Reeves

Beilstein J. Org. Chem. 2016, 12, 1081–1095, doi:10.3762/bjoc.12.103

• )propan-2-one (63) was easily generated via a two-step protocol (overall 63% yield) that started with the etherification of sodium para-methoxybenzyl alcolate with propargyl bromide [50]. The terminal alkyne on 62 was efficiently transformed into a ketone via an oxymercuration reaction using a combination

Exploring architectures displaying multimeric presentations of a trihydroxypiperidine iminosugar

• Camilla Matassini,
• Stefania Mirabella,
• Andrea Goti,
• Inmaculada Robina,
• Antonio J. Moreno-Vargas and
• Francesca Cardona

Beilstein J. Org. Chem. 2015, 11, 2631–2640, doi:10.3762/bjoc.11.282

• scaffold 5 (Scheme 3) was obtained by propargylation of pentaerythritol with propargyl bromide and NaH following a previously published procedure [35], while the dendrimeric nonavalent scaffold 6 (Scheme 3) was obtained in good yield from the reaction of tris[(propargyloxy)methyl]aminomethane with

Synthesis, antimicrobial and cytotoxicity evaluation of new cholesterol congeners

• Mohamed Ramadan El Sayed Aly,
• Hosam Ali Saad and
• Shams Hashim Abdel-Hafez

Beilstein J. Org. Chem. 2015, 11, 1922–1932, doi:10.3762/bjoc.11.208

• : (a) Propargyl bromide, NaH, Et2O/DMF (quant. for both 26 and 30); (b) 3, CuSO4·5H2O, L-AsAc, THF/H2O (89% for 27 and 74% for 31); (c) H2, Pd/C 10%, MeOH. A: Ring A of the lactose moiety, B: Ring B of the lactose moiety. Reagents and conditions: (a) Bu2SnO, MeOH; propargyl bromide, TBAI, Tol (92%); (b

Recent applications of ring-rearrangement metathesis in organic synthesis

• Sambasivarao Kotha,
• Milind Meshram,
• Priti Khedkar,
• Shaibal Banerjee and
• Deepak Deodhar

Beilstein J. Org. Chem. 2015, 11, 1833–1864, doi:10.3762/bjoc.11.199

• 134 was derived via bis-O-propargylation of compound 132 using propargyl bromide (126) under similar reaction conditions. Later, these compounds (133 and 134) were subjected to RRM and ERRM protocols under the influence of catalyst 1 in the presence of ethylene (24) to generate the tetracyclic systems

Preparation of conjugated dienoates with Bestmann ylide: Towards the synthesis of zampanolide and dactylolide using a facile linchpin approach

• Jingjing Wang,
• Samuel Z. Y. Ting and
• Joanne E. Harvey

Beilstein J. Org. Chem. 2015, 11, 1815–1822, doi:10.3762/bjoc.11.197

• the C3–C8 fragment of zampanolide, was synthesised from acrolein (12) (Scheme 2). Firstly, Barbier reaction of acrolein with propargyl bromide followed by silyl protection of the resulting alcohol afforded enyne 13. Treatment of the lithium alkynylide derived from 13 with methyl chloroformate produced

Why base-catalyzed isomerization of N-propargyl amides yields mostly allenamides rather than ynamides

• Armando Navarro-Vázquez

Beilstein J. Org. Chem. 2015, 11, 1441–1446, doi:10.3762/bjoc.11.156

• propargyl bromide (Scheme 1) [6][7]. Subsequent base-catalyzed isomerization of N-propargyl compound 2 leads to allenamide 3. Whereas in some particular cases the reaction leads to the final N-alkynyl product, in most cases, the reaction stops at the allene stage and does not further progress even when

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

• 9H-fluorene (298) and propargyl bromide, which on further treatment with 1,4-diazidobutane (300) and xylyl azides 302a–c in the presence of CuSO4·5H2O and sodium ascorbate in THF/water (1:1) gave the corresponding macrocycles (301, 42%) and (303a–c, 60–70% yield, Scheme 52). Murphy and Leyden [186

• systems which are found in streptorubin B and metacycloprodigiosin [148][149][150]. In this context, the cyclooctene 164 was reacted with the intermediate formed in situ from chloramine-T and elemental selenium [151] and yielded the allylic amine derivative 165 (75%). An N-alkylation with propargyl

• bromide gave the enyne product 166 (92%), which on further acylation of terminal alkyne with butanoyl chloride delivered compound 167 (82%). Then, it was subjected to an enyne metathesis with simple platinum salts such as PtCl2 and PtCl4 to give product 168 (79%). A subsequent reduction of the α,β

Gold-catalyzed formation of pyrrolo- and indolo-oxazin-1-one derivatives: The key structure of some marine natural products

• Sultan Taskaya,
• Nurettin Menges and
• Metin Balci

Beilstein J. Org. Chem. 2015, 11, 897–905, doi:10.3762/bjoc.11.101

• ]. Results and Discussion The starting compound 11 was synthesized via a slightly modified route by acetylation of pyrrole with trichloroacetyl chloride in 99% yield [42][43]. The propargyl ester 13 [44][45][46] was obtained in high yield from the reaction of 12 with propargyl bromide in the presence of NaH

Synthesis of carbohydrate-scaffolded thymine glycoconjugates to organize multivalency

• Anna K. Ciuk and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2015, 11, 668–674, doi:10.3762/bjoc.11.75

• groups free [14][15]. The following Williamson etherification [16] with propargyl bromide yielded the 2,3-di-O-propargylmannoside 3 in high yield. Propargylation was selected for this step to allow eventual conjugation with the known azidopropylated thymine derivative 6 [17][18][19][20] via copper(I

Further exploration of the heterocyclic diversity accessible from the allylation chemistry of indigo

• Alireza Shakoori,
• John B. Bremner,
• Mohammed K. Abdel-Hamid,
• Anthony C. Willis,
• Rachada Haritakun and
• Paul A. Keller

Beilstein J. Org. Chem. 2015, 11, 481–492, doi:10.3762/bjoc.11.54

• halides has highlighted the potential for the rapid generation of poly-heterocyclic skeletons when the halides incorporate double or triple bond moieties [3][4]. Thus propargyl bromide with indigo (1) provided access to representatives of the pyrazino[1,2-a:4,3-a']diindole, pyrido[1,2-a:3,4-b']diindole

Synthesis of divalent ligands of β-thio- and β-N-galactopyranosides and related lactosides and their evaluation as substrates and inhibitors of Trypanosoma cruzi trans-sialidase

• María Emilia Cano,
• Rosalía Agusti,
• Alejandro J. Cagnoni,
• María Florencia Tesoriero,
• José Kovensky,
• María Laura Uhrig and
• Rosa M. de Lederkremer

Beilstein J. Org. Chem. 2014, 10, 3073–3086, doi:10.3762/bjoc.10.324

• 6 (Scheme 1). On the other hand, thiolactose derivative 8 was prepared by reaction of the thiouronium salt 7 [37] and propargyl bromide in the presence of triethylamine. Compounds 3, 6 and 8, functionalized with terminal alkynyl residues, were convenient precursors for the synthesis of mono- and

End group functionalization of poly(ethylene glycol) with phenolphthalein: towards star-shaped polymers based on supramolecular interactions

• Carolin Fleischmann,
• Hendrik Wöhlk and
• Helmut Ritter

Beilstein J. Org. Chem. 2014, 10, 2263–2269, doi:10.3762/bjoc.10.235

• was prepared starting from methoxypoly(ethylene glycol) (mPEG) and propargyl bromide, whilst the latter one was utilized in a threefold excess to achieve maximum conversion of the starting material. The resulting alkyne functionalized mPEG α-methoxyethyl-ω-propargyloxypoly(ethylene glycol) (mPEG-prop

Synthesis and optical properties of pyrrolidinyl peptide nucleic acid carrying a clicked Nile red label

• Nattawut Yotapan,
• Chayan Charoenpakdee,
• Pawinee Wathanathavorn,
• Boonsong Ditmangklo,
• Hans-Achim Wagenknecht and
• Tirayut Vilaivan

Beilstein J. Org. Chem. 2014, 10, 2166–2174, doi:10.3762/bjoc.10.224

• Nile red label 1 was synthesized in 70% yield by alkylation of the known 2-hydroxy Nile red [37][38] with propargyl bromide in the presence of K2CO3 in DMF (Scheme 1). The alkyne-containing compound 1 was clicked onto the backbone of acpcPNA that had been pre-functionalized with an azidobutyl group by

• Millipak® 40 filter unit. Synthesis of propargyl Nile red 1 2-Hydroxy Nile red [37] (140.1 mg, 0.41 mmol) was dissolved in anhydrous DMF (5 mL). The solution was cooled in an ice bath followed by the addition of potassium carbonate (210.7 mg, 1.5 mmol) and propargyl bromide (100 µL, 1.5 mmol). The mixture

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

• . Synthesis of ligands The glycoclusters were prepared from the inexpensive trithiocyanuric acid (1,3-5-triazine-2,4,6-trithiol) as the heteroaromatic core (Scheme 1). Trisubstitution of the commercial trisodium salt with propargyl bromide ensured the facile preparation of 2,4,6-tris(propargylthio)-1,3,5

Convergent synthetic methodology for the construction of self-adjuvanting lipopeptide vaccines using a novel carbohydrate scaffold

• Vincent Fagan,
• Istvan Toth and
• Pavla Simerska

Beilstein J. Org. Chem. 2014, 10, 1741–1748, doi:10.3762/bjoc.10.181

• removed during work-up. The residue was alkylated with sodium hydride and propargyl bromide in dry tetrahydrofuran (THF) to give intermediate 7, which was not isolated. The methoxy ester was hydrolyzed in situ by addition of sodium hydroxide. Acid–base extraction and purification by flash chromatography

Multichromophoric sugar for fluorescence photoswitching

• Stéphane Maisonneuve,
• Rémi Métivier,
• Pei Yu,
• Keitaro Nakatani and
• Juan Xie

Beilstein J. Org. Chem. 2014, 10, 1471–1481, doi:10.3762/bjoc.10.151

• -glucopyranoside (4) To a stirred solution of methyl 6-O-trityl-α-D-glucopyranoside (3, 3.08 g, 7.05 mmol) in distilled DMF (60 mL) under argon in an ice bath, were added Bu4NI (3.07 g, 8.32 mmol) and propargyl bromide (80% solution in toluene, 2.3 mL, 20.65 mmol). The NaH (60% in mineral oil, 1.02 g, 25.5 mmol

An economical and safe procedure to synthesize 2-hydroxy-4-pentynoic acid: A precursor towards ‘clickable’ biodegradable polylactide

• Quanxuan Zhang,
• Hong Ren and
• Gregory L. Baker

Beilstein J. Org. Chem. 2014, 10, 1365–1371, doi:10.3762/bjoc.10.139

• onto polymers from a single monomer via convenient ‘click’ chemistry with organic azides. The incorporation of various pendant functional groups could effectively tailor the physicochemical properties of polylactide. The reported synthesis of 1 started from propargyl bromide and ethyl glyoxylate

• . However, both of starting materials are expensive and unstable; especially, propargyl bromide is shock-sensitive and subjected to thermal explosive decomposition, which makes the preparation of 1 impractical with high cost and high risk of explosion. Herein, we report a simple, economical and safe

• hydroxylation of propargylic malonate 5 without work-up of any intermediate. Keywords: alkylation; ‘click’ chemistry; ‘clickable’ polylactide; decomposition; diethyl 2-acetamidomalonate; 2-hydroxy-4-pentynoic acid; one-pot; optimization; propargyl bromide; propargyl tosylate; safe and economical; Introduction

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

• of the carbonyl group and deprotection. Conditions: a) NaBH4, EtOH, 0 °C, 40 min to 16 h; b) TBAF (1 M THF), THF, 0 °C, 10 min to 3.5 h. [TBAF = tetra-n-butylammonium fluoride] Synthesis of propargylic ether 18. Conditions: a) propargyl bromide, NaOH, TBAI, H2O/CH2Cl2, −20 °C → rt, 7 d; b) NaBH4

Triphenylene discotic liquid crystal trimers synthesized by Co₂(CO)₈-catalyzed terminal alkyne [2 + 2 + 2] cycloaddition

• Bin Han,
• Ping Hu,
• Bi-Qin Wang,
• Carl Redshaw and
• Ke-Qing Zhao

Beilstein J. Org. Chem. 2013, 9, 2852–2861, doi:10.3762/bjoc.9.321

• 1 and 10-undecynoic acid, undec-10-yn-1-yl p-toluenesulfonate, 5-chloro-1-pentyne, propargyl bromide, respectively. The star-shaped DLC trimers with triphenylene discogens, 4 and 5a–c, were synthesized in yields of 36–71% by the self-trimerization of monomer 2 or 3a–c catalyzed by using 10 mol % of

• Information File 1. Chemical reagents and starting materials 10-undecynoic acid, 5-chloro-1-pentyne, propargyl bromide and Co2(CO)8 were purchased from Alfa Aesar (Tianjin, China). All the other reagents and solvents were commercial products and used without further purification unless otherwise noted. 10

• . Monomer 3c, C18H6(OC5H11)5(OCH2-C≡CH): A mixture of propargyl bromide (268 mg, 2.25 mmol), K2CO3 (621 mg, 4.5 mmol), and 2-hydroxy-3,6,7,10,11-pentakis(pentyloxy)triphenylene (1, 1011 mg, 1.5 mmol) in DMF (20 mL) was stirred at 80 °C for 24 h under N2. The crude product was purified with column

Total synthesis of the endogenous inflammation resolving lipid resolvin D2 using a common lynchpin

• John Li,
• May May Leong,
• Alastair Stewart and
• Mark A. Rizzacasa

Beilstein J. Org. Chem. 2013, 9, 2762–2766, doi:10.3762/bjoc.9.310

• the ylide derived from 9 provided the alkene 10 [9] with excellent stereoselectivity. Oxidation of 10 with Dess–Martin periodinane then afforded aldehyde 7. The phosphonium salt 6 [21][22] was produced from propargyl bromide via silylation of the derived sodium salt with TIPSCl followed by reaction

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

• scale in two steps, starting from propargyl bromide (Scheme 5) [43]. Lithiation of 11 with n-BuLi and subsequent addition to pentadecanal (6) in analogous fashion to the synthesis of allenyl alcohol 7 led after column chromatography to a 57:43 mixture of the diastereomeric allenyl alcohols 12 and 13 in

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

• a solution of propargyl bromide (commercial source: 80% in toluene) (1.5 equiv; 7.5 mmol). The reaction was controlled by TLC and when it was finished, it was diluted with Et2O (30 mL) and then brine was added. The organic layer was washed in a separation funnel with brine to extract all the DMF (5

Design and synthesis of tag-free photoprobes for the identification of the molecular target for CCG-1423, a novel inhibitor of the Rho/MKL1/SRF signaling pathway

• Jessica L. Bell,
• Andrew J. Haak,
• Susan M. Wade,
• Yihan Sun,
• Richard R. Neubig and
• Scott D. Larsen

Beilstein J. Org. Chem. 2013, 9, 966–973, doi:10.3762/bjoc.9.111

• the photoaffinity probe 19 is shown in Scheme 3. Aniline 15 was Boc-protected [24], and then alkylated using propargyl bromide to produce ether 16. Following deprotection, aniline 17 was coupled with Boc-protected nipecotic acid (4), giving amide 18 after deprotection. Final coupling with 3

• -benzoylbenzoic acid afforded the final probe 19. Synthesis of a photoprobe based on the most active model 8c is shown in Scheme 4. Acid 20 was esterified prior to alkylation with propargyl bromide, affording ester 22. Saponification, followed by amidation with the previously prepared piperidine 6c, provided the

Superstructures of fluorescent cyclodextrin via click-reaction

• Arkadius Maciollek,
• Helmut Ritter and
• Rainer Beckert

Beilstein J. Org. Chem. 2013, 9, 827–831, doi:10.3762/bjoc.9.94

• fluorescent nature [1][2]. These optical properties can be used for the development of sensor molecules, blue emitting dyes, luminescent materials or as donor–(π-conjugated-bridge)–acceptor-type dyes in dye-sensitized solar cells [3][4][5]. The etherification of 4-hydroxythiazole by using propargyl bromide

New enzymatically polymerized copolymers from 4-tert-butylphenol and 4-ferrocenylphenol and their modification and inclusion complexes with β-cyclodextrin

• Adam Mondrzyk,
• Beate Mondrzik,
• Sabrina Gingter and
• Helmut Ritter

Beilstein J. Org. Chem. 2012, 8, 2118–2123, doi:10.3762/bjoc.8.238

• in the IR spectrum of copolymer 4. Therefore, 4 is a copolymer comprising the ortho–ortho- and oxy-ortho-connected phenyl moieties. The modified copolymer 5 was synthetized from copolymer 4 by alkylation with propargyl bromide under alkaline conditions. Then, the alkyne-functionalized copolymer 5 was

• mmol) propargyl bromide and 0.14 g (1.0 mmol) potassium carbonate are dispersed in 20 mL dry THF in a one-neck flask under an argon atmosphere. The dispersion is stirred under reflux for 24 hours. The product is precipitated in hexane and dried in vacuo to give 0.28 g (80% yield). FTIR (diamond) : 2962

• copolymerization of 4-ferrocenylphenol with 4-tert-butylphenol. The 4-ferrocenylphenol obviously tolerates the oxidative environment of H2O2. Furthermore, ortho–ortho- and oxy-ortho-connected phenol monomers were found. However, the free hydroxy groups were subjected to alkylation with propargyl bromide and