New α- and β-cyclodextrin derivatives with cinchona alkaloids used in asymmetric organocatalytic reactions

• Iveta Chena Tichá,
• Simona Hybelbauerová and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2019, 15, 830–839, doi:10.3762/bjoc.15.80

• ) the cinchona alkaloid moiety can be successfully attached to CD scaffolds through a CuAAC reaction, (ii) the permethylated cinchona alkaloid–CD catalysts showed better results than the non-methylated CDs analogues in the AAA reaction, (iii) promising enantiomeric excesses are achieved, and (iv) the

• catalysts, a disubstituted α-CD derivative as a pure AD regioisomer with two identical cinchona alkaloid residues was prepared and tested in the AAA reaction. Our study shows that the CuAAC reaction is a good and high-yielding method for the functionalization of the CD skeleton when attaching sterically

• of reaction affording the products with high to excellent yields (95%, 5a–d, Table 1, entries 8–11). Conversely, the product yield was low when using DMF for a CuAAC reaction with α-CD resulting in only 38% of product 4a after 48 hours (Table 1, entry 12). Synthesis of monosubstituted methylated CD

Polyaminoazide mixtures for the synthesis of pH-responsive calixarene nanosponges

• Antonella Di Vincenzo,
• Antonio Palumbo Piccionello,
• Alberto Spinella,
• Delia Chillura Martino,
• Marco Russo and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2019, 15, 633–641, doi:10.3762/bjoc.15.59

• ) of polyaminoazide mixtures, which were in turn used for the preparation of CaNSs materials with pH-tunable properties, by reaction with the (5,11,17,23-tetra(tert-butyl))-(25,26,27,28-tetrakis(propargyloxy)calix[4]arene (Ca) under the CuAAC reaction conditions. In turn, the synthon Ca is obtained by

• isolated and characterized the relevant product mixtures, indicated hereinafter as mixture I and II, respectively, the latter ones were employed as the reticulating agents for the CuAAC reaction with the aforementioned propargyloxy-calixarene Ca, in order to obtain two different materials, indicated as

• nanosponges Having obtained the polyaminoazide mixures I and II, these were reacted with the propargyloxycalixarene Ca by means of the CuAAC reaction, to obtain the desired nanosponge materials CaNS-I and CaNS-II. Noticeably, by adopting the same reaction conditions used for the synthesis of CaNSs reported in

Synthesis and fluorescent properties of N(9)-alkylated 2-amino-6-triazolylpurines and 7-deazapurines

• Andrejs Šišuļins,
• Jonas Bucevičius,
• Yu-Ting Tseng,
• Irina Novosjolova,
• Kaspars Traskovskis,
• Ērika Bizdēna,
• Huan-Tsung Chang,
• Sigitas Tumkevičius and
• Māris Turks

Beilstein J. Org. Chem. 2019, 15, 474–489, doi:10.3762/bjoc.15.41

• transformed into the title compounds by CuAAC reaction. The designed compounds belong to the push–pull systems and possess promising fluorescence properties with quantum yields in the range from 28% to 60% in acetonitrile solution. Due to electron-withdrawing properties of purine and 7-deazapurine

• intermediates 2 and 3 in hand, we proceeded with the synthesis and structure elucidation of the designed structures G and H (Figure 1) which are represented by compounds 7–11 in Scheme 1. Firstly, we prepared a regioisomeric compound 5 by repeating the previously elaborated sequence of double CuAAC reaction (2

• the synthetic intermediates obtained in the SNAr reaction (e.g., 6-azido-9-heptyl-2-(piperidin-1-yl)purine (6b)) exists in both tetrazolo- and azido-tautomeric forms in CD3CN solution. The presence of the latter permits the CuAAC reaction with terminal acetylenes and gave a rise to the title compounds

Copper(I)-catalyzed tandem reaction: synthesis of 1,4-disubstituted 1,2,3-triazoles from alkyl diacyl peroxides, azidotrimethylsilane, and alkynes

• Muhammad Israr,
• Changqing Ye,
• Munira Taj Muhammad,
• Yajun Li and
• Hongli Bao

Beilstein J. Org. Chem. 2018, 14, 2916–2922, doi:10.3762/bjoc.14.270

• Academy of Sciences, 155 Yangqiao Road West, Fuzhou, Fujian 350002, P. R. China University of Chinese academy of Science (UCAS), Beijing 100190, P. R. China 10.3762/bjoc.14.270 Abstract A copper-catalyzed azide–alkyne cycloaddition (CuAAC) reaction for the synthesis of 1,4-disubstituted 1,2,3-triazoles

• , making this protocol operationally simple. The Cu(I) catalyst not only participates in the alkyl diacyl peroxides decomposition to afford alkyl azides but also catalyzes the subsequent CuAAC reaction to produce the 1,2,3-triazoles. Keywords: alkyl diacyl peroxides; azidotrimethylsilane; click reaction

• research and synthesis of functionalized compounds that have applications in medicinal chemistry, drug discovery, materials chemistry, and as well as in bioconjugates [2][3][4][5][6][7][8][9][10][11][12]. The copper-catalyzed azide–alkyne cycloaddition (CuAAC) reaction [13][14][15][16][17][18][19][20][21

Revisiting ring-degenerate rearrangements of 1-substituted-4-imino-1,2,3-triazoles

• James T. Fletcher,
• Matthew D. Hanson,
• Joseph A. Christensen and
• Eric M. Villa

Beilstein J. Org. Chem. 2018, 14, 2098–2105, doi:10.3762/bjoc.14.184

• recent years [1][2][3][4][5][6][7], enabled by efficient preparation from the Sharpless–Meldal copper-catalyzed azide–alkyne cycloaddition (CuAAC) reaction [8][9][10][11]. Click chelators with a variety of N-donor units connected at the 4-triazolyl position have been reported, including pyridine [12][13

• useful for solubilizing the range of analogs included in the study and facilitating product work-up via simple evaporation. High-temperature conditions used a 1:1 t-BuOH/H2O solvent system at 70 °C, identified as useful in a previous study focusing on tandem CuAAC reaction development [35]. Importantly

Synthesis of new p-tert-butylcalix[4]arene-based polyammonium triazolyl amphiphiles and their binding with nucleoside phosphates

• Vladimir A. Burilov,
• Guzaliya A. Fatikhova,
• Mariya N. Dokuchaeva,
• Ramil I. Nugmanov,
• Diana A. Mironova,
• Pavel V. Dorovatovskii,
• Victor N. Khrustalev,
• Svetlana E. Solovieva and
• Igor S. Antipin

Beilstein J. Org. Chem. 2018, 14, 1980–1993, doi:10.3762/bjoc.14.173

• (CuAAC) reaction [28]. An alternative way is the functionalization of calix[4]arenes by terminal alkynyl groups. However, in this case further transformations by CuAAC reactions are limited mainly due to the fact that low molecular weight organic azides, especially containing less than 3 carbon atoms are

• macrocycles’ aromatic rings have been synthesized and used for the preparation of water-soluble triazolyl amphiphilic receptors with two or four polyammonium headgroups by CuAAC reaction with 3-bis[2-(tert-butoxycarbonylamino)ethyl]propargylamine. These macrocycles form stable aggregates in aqueous solutions

Hyper-reticulated calixarene polymers: a new example of entirely synthetic nanosponge materials

• Alberto Spinella,
• Marco Russo,
• Antonella Di Vincenzo,
• Delia Chillura Martino and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2018, 14, 1498–1507, doi:10.3762/bjoc.14.127

• preliminary tests to assess their supramolecular absorption abilities towards a set of suitable organic guests, selected as pollutant models. The synthesis was accomplished by means of a CuAAC reaction between a tetrakis(propargyloxy)calix[4]arene and an alkyl diazide. The formation of the polymeric network

• extend and possibly improve the supramolecular binding abilities of CyNSs, mixed cyclodextrin-calixarene co-polymers nanosponges (CyCaNSs) were recently synthesized by exploiting a classical “click-chemistry” approach, namely the CuAAC reaction (Cu-catalyzed azide–alkyne cycloaddition [28][29][30

• number of azido groups present in the molecule. The actual accomplishment of the CuAAC reaction, and therefore the formation of the reticulated polymer network, was first assessed by means of FTIR spectroscopy. The FTIR spectra of the propargyloxycalixarene precursor Ca-OP, of the diazide A2 and the

Recent applications of click chemistry for the functionalization of gold nanoparticles and their conversion to glyco-gold nanoparticles

• Vivek Poonthiyil,
• Thisbe K. Lindhorst,
• Vladimir B. Golovko and
• Antony J. Fairbanks

Beilstein J. Org. Chem. 2018, 14, 11–24, doi:10.3762/bjoc.14.2

• , polymeric and dendronic alkynes of different sizes and hydrophilicities [63][64]. CuAAC worked with a catalytic amount of [Cu(I)tren(CH2Ph6)]Br under ambient conditions with good yields and without any particle aggregation. Following these reports, several groups have used the CuAAC reaction of AuNPs as a

• -electrode system to cover the AuNP surfaces with alkyne-terminated SAMs (Scheme 10). Next, a CuAAC reaction was used to couple the alkyne-functionalized AuNPs to an azide-linked sialic acid derivative, to produce GAuNPs attached to the carbon electrode. This sialic acid-functionalized GAuNP-carbon electrode

• /decomposition during the CuAAC [57]. It seems therefore that our attempts to synthesize GAuNPs using the one pot glycosyl azide/CuAAC reaction ran into the same limitations as reported by these three groups. Boisselier et al. reported that by employing specific conditions, namely stoichiometric quantities of

Synthetic mRNA capping

• Fabian Muttach,
• Nils Muthmann and
• Andrea Rentmeister

Beilstein J. Org. Chem. 2017, 13, 2819–2832, doi:10.3762/bjoc.13.274

• dyes which could be applied as FRET pair. In this case, labeling was achieved in two bioorthogonal reactions, an iEDDA and a SPAAC reaction. Furthermore, dual modification with an azido and an alkyne function enabled fluorophore/biotin labeling using a combination of SPAAC and CuAAC reaction. Efficient

• , different hypermethylated cap analogues with a 2′-azido moiety allowed for reaction with an alkyne-modified RNA in a CuAAC reaction to yield cap modified RNA – albeit with a non-natural linkage (Figure 7A) [120]. This capping strategy also worked with an alkyne-modified triphosphorylated RNA and 5′-azido

• modified methylguanosine resulting in a capped RNA containing a triazole linkage after CuAAC reaction (Figure 7B) [121]. In a similar approach a 5′-azido-modified RNA was prepared by solid-phase synthesis and reacted with an alkyne-functionalized m7G-cap analogue in a CuAAC reaction [122]. Besides its

Solvent-free copper-catalyzed click chemistry for the synthesis of N-heterocyclic hybrids based on quinoline and 1,2,3-triazole

• Martina Tireli,
• Silvija Maračić,
• Stipe Lukin,
• Marina Juribašić Kulcsár,
• Dijana Žilić,
• Mario Cetina,
• Ivan Halasz,
• Silvana Raić-Malić and
• Krunoslav Užarević

Beilstein J. Org. Chem. 2017, 13, 2352–2363, doi:10.3762/bjoc.13.232

• states for the mechanochemical CuAAC reaction of target quinoline derivatives and p-substituted phenyl azides. We have also investigated the effect of the p-substituent in the azide on the reaction progress and yields. Direct monitoring by in situ Raman spectroscopy was used to gain an insight into the

• milling CuAAC reaction pathway when using different catalysts. The electronic structure of Cu catalysts after the reaction completion was assayed by electron spin resonance (ESR) spectroscopy. All milling reactions, except the one using copper(0) as catalyst, were compared to solution procedures to

• quinoline and 1,2,3-triazole scaffolds. Based on the known protocols for click conjugation [39] that include direct utilization of a Cu(I) source as well as alternative creation of Cu(I) from a Cu(II) source or elemental copper, initially we have examined the most common CuAAC reaction procedure using in

An eco-compatible strategy for the diversity-oriented synthesis of macrocycles exploiting carbohydrate-derived building blocks

• Sushil K. Maurya and
• Rohit Rana

Beilstein J. Org. Chem. 2017, 13, 1106–1118, doi:10.3762/bjoc.13.110

• the iterative use of readily available sugar-derived alkyne/azide–alkene building blocks coupled through copper catalyzed azide–alkyne cycloaddition (CuAAC) reaction followed by pairing of the linear cyclo-adduct using greener reaction conditions. The eco-compatibility, mild reaction conditions

• ] glycosides and macrocyclic glycolipids [11]. Similarly, the copper-catalyzed azide–alkyne cycloaddition (CuAAC) reaction has found wide application in medicinal chemistry [33], biology [34][35], polymer chemistry [36], carbohydrates [37][38][39][40], peptides [41][42][43][44] and in materials science [45][46

• incorporating diversity-oriented synthesis (DOS). These moieties can be easily furnished with alkyne or azide functionality with routine synthetic transformation protocols that allow facile access to mono- as well as poly-functionalized derivatives via CuAAC reaction. The approach enables the rapid synthesis of

Construction of bis-, tris- and tetrahydrazones by addition of azoalkenes to amines and ammonia

• Artem N. Semakin,
• Aleksandr O. Kokuev,
• Yulia V. Nelyubina,
• Alexey Yu. Sukhorukov,
• Petr A. Zhmurov,
• Sema L. Ioffe and
• Vladimir A. Tartakovsky

Beilstein J. Org. Chem. 2016, 12, 2471–2477, doi:10.3762/bjoc.12.241

• on a support. This was demonstrated by the synthesis of a mixed triazole-hydrazone ligand 10 by CuAAC reaction of 3 with phenyl azide (Scheme 3) (for application of mixed triazole-imine ligands see [31][32][34]). Reaction of α-halogen-substituted hydrazones 1 with ammonia Addition of α-halohydrazones

Dinuclear thiazolylidene copper complex as highly active catalyst for azid–alkyne cycloadditions

• Anne L. Schöffler,
• Ata Makarem,
• Frank Rominger and
• Bernd F. Straub

Beilstein J. Org. Chem. 2016, 12, 1566–1572, doi:10.3762/bjoc.12.151

• conditions [4][5][6]. The CuAAC reaction has found broad application in the preparation of peptide-conjugates [7][8], multicomponent syntheses [9], preparation of hydrogels, microgels and nanogels [10], (anion) supramolecular chemistry [11][12], in medicinal chemistry [13], therapeutics, biomaterials and

• unclear for many years. The first proposals for the mechanism suggested the participation of only one copper(I) atom in the key elementary steps. In 2005, Fokin and Finn determined the reaction rate of a CuAAC reaction to be second order in the concentration of copper [32]. Since then, the understanding

• characterize thiazolylidene copper acetylides. Addition of acetic acid greatly increases the rate of the CuAAC reaction with ethyl propiolate, so that half-conversion is reached after 6 min (Table 1, entry 5, red squares). These observations are again consistent with the formation of a thermodynamically stable

Beta-hydroxyphosphonate ribonucleoside analogues derived from 4-substituted-1,2,3-triazoles as IMP/GMP mimics: synthesis and biological evaluation

• Tai Nguyen Van,
• Audrey Hospital,
• Corinne Lionne,
• Lars P. Jordheim,
• Charles Dumontet,
• Christian Périgaud,
• Laurent Chaloin and
• Suzanne Peyrottes

Beilstein J. Org. Chem. 2016, 12, 1476–1486, doi:10.3762/bjoc.12.144

• categories: aromatic alkynes with various substituents (methoxy, amino, formyl…) in ortho, meta or para position, and short alkyne chains such as 3-butyn-2-one or methylpropiolate. Starting from intermediate 2, the CuAAC reaction was either catalysed by CuI or CuSO4 (Table 1) and gave rise to the fully

Application of Cu(I)-catalyzed azide–alkyne cycloaddition for the design and synthesis of sequence specific probes targeting double-stranded DNA

• Svetlana V. Vasilyeva,
• Vyacheslav V. Filichev and
• Alexandre S. Boutorine

Beilstein J. Org. Chem. 2016, 12, 1348–1360, doi:10.3762/bjoc.12.128

• differ in the length and nature of the 3'-linker were synthesized and used for further conjugations [17][30]. Synthesis of polyamide-TFO conjugates by CuAAC reaction To establish conditions for the synthesis of TFO-MGB conjugates we used 5'-alkyne modified parallel TFOs (15–17) in combination with the N

• –19) and mass spectrometry identification (Table S2); details of synthesis of Polyamide-TFO conjugates by CuAAC reaction and mass-spectrometry characteristics (Tables S3 and S4, Figure S1) are provided in Supporting Information File 1. Supporting Information File 242: Experimenal and analytical data

Copper-catalyzed [3 + 2] cycloaddition of (phenylethynyl)di-p-tolylstibane with organic azides

• Mizuki Yamada,
• Mio Matsumura,
• Yuki Uchida,
• Masatoshi Kawahata,
• Yuki Murata,
• Naoki Kakusawa,
• Kentaro Yamaguchi and
• Shuji Yasuike

Beilstein J. Org. Chem. 2016, 12, 1309–1313, doi:10.3762/bjoc.12.123

• recovered (84%). These two experiments indicate that the formation of 5-H-triazole 4 progresses via 5-stibanotriazole 3a, the cycloaddition product of 1 with 2a. To investigate the scope and limitations of the CuAAC reaction of stibane, ethynylstibane 1 was reacted with a series of organic azides 2 under

• yields. The CuAAC reaction of 1 with aryl azides such as 4-methylphenyl and 4-cyanophenyl azide gave a complex mixture, presumably due to the steric hindrance introduced by the aryl groups. The regiochemistry of 5-stibanotriazole 3a was elucidated by 1H NMR and confirmed by single-crystal X-ray analysis

Bi- and trinuclear copper(I) complexes of 1,2,3-triazole-tethered NHC ligands: synthesis, structure, and catalytic properties

• Shaojin Gu,
• Jiehao Du,
• Jingjing Huang,
• Huan Xia,
• Ling Yang,
• Weilin Xu and
• Chunxin Lu

Beilstein J. Org. Chem. 2016, 12, 863–873, doi:10.3762/bjoc.12.85

• imidazolium backbone and N substituents. The copper–NHC complexes tested are highly active for the Cu-catalyzed azide–alkyne cycloaddition (CuAAC) reaction in an air atmosphere at room temperature in a CH3CN solution. Complex 4 is the most efficient catalyst among these polynuclear complexes in an air

• atmosphere at room temperature. Keywords: copper; CuAAC reaction; : N-heterocylic carbene; 1,2,3-triazole; Introduction N-Heterocyclic carbene (NHC) have interesting electronic and structural properties. This resulted in their use as versatile ligands in organometallic chemistry and homogeneous catalysis

• Inspired by the catalytic activity of Cu(I) species supported by NHC ligand in Cu-catalyzed azide–alkyne cycloaddition (CuAAC) reaction under mild conditions, copper complexes 2–6 were investigated in the CuAAC reaction of azide and phenylacetylene. Firstly, we compared the catalytic activity of different

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

• trimesoyl chloride, as we recently reported [21]. The CuAAC reaction of the azido derivative 4 (4.0 equivalents) with scaffold 5 was performed with CuSO4/sodium ascorbate in THF/H2O 2:1 in a MW reactor at 80 °C for 45 minutes, affording the expected tetravalent iminosugar derivative 7 in 88% yield after

• tried the deprotection of the acetonide groups prior to CuAAC reaction. Compound 4 was treated with 1 M HCl in MeOH at room temperature for 16 hours and then passed through Dowex 50WX8-200, following the general purification procedure previously described, to obtain the polyhydroxylated azido derivative

• 10 [25] in 90% yield. The CuAAC reaction of compound 10 (9 equiv) with the nonavalent alkyne scaffold 6, performed with CuSO4/sodium ascorbate in THF/H2O 2:1 heating in a MW reactor at 80 °C for 90 minutes, gave the nonavalent compound 11 in 23% yield, after flash column chromatography (Scheme 5

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

• investigated and recognized as an epoch-making progress in organic synthesis and green chemistry [11][12][13][14][15]. After many years of research, it was proven that the Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC reaction) could be performed under various conditions according to the need of click

• from a double CuAAC reaction between various sources of 1,3-butadiynes with the substituted azides. In general, two different methods have been developed for the construction of the 4,4'-bitriazoles: (1) The one-pot double CuAAC reaction of 1,3-butadiyne with azides. (2) Two successive CuAAC reactions

• et al. also developed this three-step procedure (CuAAC–deprotection–CuAAC) into a one-pot fashion with moderate overall yield (34–49%) [19]. Similar to Fiandanese’s strategy, Aizpurua et al. developed another synthetic method [20]: Starting with the CuAAC reaction of propargyl alcohol (7) with

Effective ascorbate-free and photolatent click reactions in water using a photoreducible copper(II)-ethylenediamine precatalyst

• Redouane Beniazza,
• Natalia Bayo,
• Florian Molton,
• Carole Duboc,
• Stéphane Massip,
• Nathan McClenaghan,
• Dominique Lastécouères and
• Jean-Marc Vincent

Beilstein J. Org. Chem. 2015, 11, 1950–1959, doi:10.3762/bjoc.11.211

• such as MeOH or THF [11][12][13]. Consequently, efficient reduction could be achieved by simply exposing the solutions of the Cu(II) complexes to ambient light. Importantly, the photogenerated Cu(I) species were shown to be extremely reactive for the CuAAC reaction when conducting the reactions in

Synthesis of alpha-tetrasubstituted triazoles by copper-catalyzed silyl deprotection/azide cycloaddition

• Zachary L. Palchak,
• Paula T. Nguyen and
• Catharine H. Larsen

Beilstein J. Org. Chem. 2015, 11, 1425–1433, doi:10.3762/bjoc.11.154

• -protected alkynes have been converted to triazoles via a one-pot silyl deprotection CuAAC reaction [30][31][32][33], TIPS-protected alkynes have not. As the triisopropylsilyl protecting group is more difficult to remove than the less hindered trimethylsilyl, conditions for TIPS deprotection include 1.5

• equiv of AgF or Cu(OAc)2 combined with syringe pump addition of TBAF [34][35]. An additional difficulty is that Ellman’s alpha-tetrasubstituted triazoles are synthesized by CuAAC reaction with desilylated, purified tetrasubstituted propargylic amines [6][7][8]. Therefore, the goal was to develop the

Multivalent polyglycerol supported imidazolidin-4-one organocatalysts for enantioselective Friedel–Crafts alkylations

• Tommaso Pecchioli,
• Manoj Kumar Muthyala,
• Rainer Haag and
• Mathias Christmann

Beilstein J. Org. Chem. 2015, 11, 730–738, doi:10.3762/bjoc.11.83

• described. A modified tyrosine-based imidazolidin-4-one was grafted to a soluble high-loading hyperbranched polyglycerol via a copper-catalyzed alkyne–azide cycloaddition (CuAAC) reaction and readily purified by dialysis. The efficiency of differently functionalized multivalent organocatalysts 4a–c was

• -ones PG-95 (4a), PG-57 (4b) and PG-30 (4c) representing different degrees of functionalization: 95% (4a), 57% (4b) and 30% (4c), respectively. An (S)-tyrosine-derived imidazolidin-4-one 5 was anchored to the polymeric support through a CuAAC reaction. Following the same strategy, a monovalent analog 8

• of hyperbranched polyglycerol-supported and G1 dendronized imidazolidin-4-ones 4a–c and 8 using a CuAAC reaction. Reaction conditions: (a) 1 (1.0 equiv), MsCl (1.2 equiv, with respect to degrees of functionalization), pyridine, 25 °C, 16 h, 76% 2a, 82% 2b and 87% 2c. (b) 2a–c (1.0 equiv), NaN3 (3.0

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

• our group [11][12], the last stages of the multivalent probe synthesis involved the attachment of peracetylated azido iminosugars 4 on the scaffolds via CuAAC reaction and afterwards O-deacetylation using an anion exchange resin. First attempts to perform CuAAC reactions with triyne substrate 6b

• carefully degassed conditions and the desired protected cluster 12b could be obtained in 56% yield after purification on silica gel (Scheme 2). The major side-product observed which could not be isolated in pure form may correspond to CuAAC reaction of the azido iminosugar 4a with the terminal alkyne

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

• , and a peak at m/z 988.3291, corresponding to the [M + 2Na]2+ cation, was observed consistent with the proposed structure. Conclusion Mono- and bivalent β-N and β-S-galactopyranosides and lactosides supported on sugar scaffolds were synthesized by a convergent approach using the CuAAC reaction

Sequential decarboxylative azide–alkyne cycloaddition and dehydrogenative coupling reactions: one-pot synthesis of polycyclic fused triazoles

• Kuppusamy Bharathimohan,
• Thanasekaran Ponpandian,
• A. Jafar Ahamed and
• Nattamai Bhuvanesh

Beilstein J. Org. Chem. 2014, 10, 3031–3037, doi:10.3762/bjoc.10.321

• organic azides. This kind of decarboxylative CuAAC reaction has not been further investigated. Transition metal-mediated C–H bond activation has become a hot topic in recent years [7][8][9][10][11]. Formally, it requires insertion of a transition metal (usually Pd, Ru, Rh or Ir) across a strong C–H bond

• were developed for the synthesis of fused triazoles [40]. Ackermann referred to an intramolecular dehydrogenative coupling of 1,4-disubstituted triazoles to achieve tri- and tetracyclic triazoles [34]. Recently, Lautens et al. [41] described a one-pot synthesis of fused triazoles through CuAAC reaction

• of our knowledge, until now there have been no reports describing the combination of decarboxylative CuAAC reaction and C–H activation in an one-pot fashion. This strategy describes the preparation of fused triazoles by one-pot reaction of 2-alkynoic acid and azide derivatives. Results and Discussion