Versatile synthesis of end-reactive polyrotaxanes applicable to fabrication of supramolecular biomaterials

• Atsushi Tamura,
• Asato Tonegawa,
• Yoshinori Arisaka and
• Nobuhiko Yui

Beilstein J. Org. Chem. 2016, 12, 2883–2892, doi:10.3762/bjoc.12.287

• an axle polymer and commercially available 4-substituted benzoic acids as capping reagents. The terminal 2-amino-3-phenylpropyl groups of PEG-Ph-NH2 block the dethreading of the α-CDs after capping with 4-substituted benzoic acids. By this method, two series of azide group-terminated polyrotaxanes

• functional PRXs and can be applied to the fabrication of PRX-based supramolecular biomaterials. Keywords: azide group; biomaterials; click chemistry; cyclodextrin; polyrotaxane; Introduction Polyrotaxanes (PRXs) are a class of interlocked polymers that consist of an inclusion complex of cyclodextrins (CDs

• drug delivery [31]. Herein, alkynyl group-bearing fluorescent molecules were modified at the terminal azide group of the PRXs, and intracellular fluorescence imaging of the PRXs was performed to verify whether the terminally modified fluorescent molecules could be used for fluorescence imaging. First

Catalytic Wittig and aza-Wittig reactions

• Zhiqi Lao and
• Patrick H. Toy

Beilstein J. Org. Chem. 2016, 12, 2577–2587, doi:10.3762/bjoc.12.253

• seems that the required isocyanate or azide group containing precursors are readily synthesized from simple starting materials. Conclusion While great advances have been reported regarding the development of catalytic Wittig and aza-Wittig reactions, it remains to be seen how widely these methods will

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

• [10][11][34]. Several different bifunctional linkers were designed and synthesized (Figure 3). All of them contain, on one side, an alkyne or azide group for "click chemistry” and, on the other side, either an amino group for interaction with electrophiles (for example, activated terminal phosphates

• . The linker 4 is designed for functionalization of either commercial amino-modified oligonucleotides or amine-bearing polyamides. It contains an alkyne group for CuAAC and an activated ester for the acylation of amino groups. The linkers 5–7 of different lengths contain an azide group for CuAAC and a

Synthesis of 2,1-benzisoxazole-3(1H)-ones by base-mediated photochemical N–O bond-forming cyclization of 2-azidobenzoic acids

• Daria Yu. Dzhons and
• Andrei V. Budruev

Beilstein J. Org. Chem. 2016, 12, 874–881, doi:10.3762/bjoc.12.86

• photochemical sensitivity of both the C–I bond and the azide group present in 1e, unlike the others, complicates the synthesis of benzisoxazolone 2e. The photolysis of 1e under these conditions resulted in the formation of several products in low yields. Therefore, the synthesis towards benzisoxazolone 2e was

Synthesis and in vitro cytotoxicity of acetylated 3-fluoro, 4-fluoro and 3,4-difluoro analogs of D-glucosamine and D-galactosamine

• Štěpán Horník,
• Lucie Červenková Šťastná,
• Petra Cuřínová,
• Jan Sýkora,
• Kateřina Káňová,
• Roman Hrstka,
• Ivana Císařová,
• Martin Dračínský and
• Jindřich Karban

Beilstein J. Org. Chem. 2016, 12, 750–759, doi:10.3762/bjoc.12.75

• ). Suggested mechanisms for deoxofluorination at C-3 of 1,6-anhydro-β-D-glucohexopyranose derivatives. A) participation of the O-benzyl group; B) participation of the azide group; C) internal fluorine attack, concerted mechanism; D) internal fluorine attack, contact ion pair mechanism. Formation of oxazoline

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

• method for the formation of disymmetric bistriazoles [66]. The authors introduced the azide group (69) by the coupling of the protected amine functionality to the polymer substrate for the first CuAAC reaction (Scheme 23). Then, the treatment of the amine-containing mono-triazole intermediate 71 with the

• diazo transfer agent (imidazole-1-sulfonyl azide) was performed to convert the amine group into the corresponding azide group, which provided a polymeric substrate for the second CuAAC reaction to give the desired bistriazoles (Scheme 23). In 2009, Zhu and co-workers found that copper(II) acetate (Cu

• (OAc)2) could catalyze the Huisgen alkyne-azide cycloaddition reactions without the addition of the reducing agents and could be produced in high yield when the substrate contains the chelating azide group [67]. Then they synthesized the bifunctional compounds with chelating azide groups and

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

• (Scheme 2). Staudinger reduction of the azide group and Boc-protection in the same pot gave 9 and subsequent click reaction with the thymine derivative 6 the isopropylidene-protected dimeric thymine glycoconjugate 10 in good yield. This could be alkylated employing the bromoethyl mannoside 11 [11] in an

Direct access to pyrido/pyrrolo[2,1-b]quinazolin-9(1H)-ones through silver-mediated intramolecular alkyne hydroamination reactions

• Hengshuai Wang,
• Shengchao Jiao,
• Kerong Chen,
• Xu Zhang,
• Linxiang Zhao,
• Dan Liu,
• Yu Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2015, 11, 416–424, doi:10.3762/bjoc.11.47

• dangerous substrates bearing an azide group, and require a high reaction temperature and a long reaction time [2][10]. Recently, transition metal catalyzed hydroamination of alkynes [14][15][16][17][18][19][20][21][22][23][24][25][26], alkenes [15][27][28][29][30][31] and dienes [32][33] has been widely

The reactions of 2-ethoxymethylidene-3-oxo esters and their analogues with 5-aminotetrazole as a way to novel azaheterocycles

• Marina V. Goryaeva,
• Yanina V. Burgart,
• Marina A. Ezhikova,
• Mikhail I. Kodess and
• Viktor I. Saloutin

Beilstein J. Org. Chem. 2015, 11, 385–391, doi:10.3762/bjoc.11.44

• , which are typical for the vibration of the azide group in the IR sperctrum [25]. The 13C NMR spectra of compounds 2a–c in CDCl3 showed the resonance of the carbon atom C-2 at δ 163.39–163.89 ppm, which is characteristic of the azide form [22][23]. In contrast to polyfluoroalkylated analogues 2a,b, 4

• activity against HSV-1 was obtained by cyclization of ethyl 2-dimethylaminomethyliden-4,4,4-trifluoroacetoacetate [27]. The formation of 2-(tetrazolylamino)pyrimidine 5 is the result of nucleophilic substitution of the azide group in intermediate 2a by the aminotetrazole fragment, as the azide group is a

• of compound 7 in the solid state did not have the absorption band of the azide group at ν 2100–2200 cm−1, but contained the absorption bands of hydroxy groups O–H (ν 3419 cm−1) and carbonyl fragments C=O (ν 1715 cm-1). The 1H and 13C NMR spectra in DMSO-d6 contained one set of the signals

Functionalized branched EDOT-terthiophene copolymer films by electropolymerization and post-polymerization “click”-reactions

• Miriam Goll,
• Adrian Ruff,
• Erna Muks,
• Felix Goerigk,
• Beatrice Omiecienski,
• Ines Ruff,
• Rafael C. González-Cano,
• Juan T. Lopez Navarrete,
• M. Carmen Ruiz Delgado and
• Sabine Ludwigs

Beilstein J. Org. Chem. 2015, 11, 335–347, doi:10.3762/bjoc.11.39

• modification over the whole film. The integrity of the redox and optical behavior upon modification of the P(EDOT-N3-co-3T)-1:1 with sulfonic acid with regard to the parent copolymer was further proven by cyclic voltammetry and in situ spectroelectrochemistry. It was recently demonstrated that the azide group

Articulated rods – a novel class of molecular rods based on oligospiroketals (OSK)

• Pablo Wessig,
• Roswitha Merkel and
• Peter Müller

Beilstein J. Org. Chem. 2015, 11, 74–84, doi:10.3762/bjoc.11.11

• , the PMB group was cleaved by DDQ to give the orthogonally protected trispiro rod 8 (Scheme 1). To demonstrate the capability of the approach outlined in Figure 3 we selectively activated both sides of building block 8 either by introduction of an azide group (9) or liberation of the terminal alkyne by

Triazol-substituted titanocenes by strain-driven 1,3-dipolar cycloadditions

• Andreas Gansäuer,
• Andreas Okkel,
• Lukas Schwach,
• Laura Wagner,
• Anja Selig and
• Aram Prokop

Beilstein J. Org. Chem. 2014, 10, 1630–1637, doi:10.3762/bjoc.10.169

• bulkiness of the ligand’s substituents. It should be noted that polyether groups can be readily incorporated into cationic titanocenes. This suggests that the cationic titanocenes can be readily immobilized by covalent binding to PEG. In general, our results clearly demonstrate that the azide group is

Bis(β-lactosyl)-[60]fullerene as novel class of glycolipids useful for the detection and the decontamination of biological toxins of the Ricinus communis family

• Hirofumi Dohi,
• Takeru Kanazawa,
• Akihiro Saito,
• Keita Sato,
• Hirotaka Uzawa,
• Yasuo Seto and
• Yoshihiro Nishida

Beilstein J. Org. Chem. 2014, 10, 1504–1512, doi:10.3762/bjoc.10.155

• between C60 and the azide group in 6-azidohexyl β-lactoside per-O-acetate. A colloidal aqueous solution with brown color was prepared from deprotected bis(lactosyl)-C60 and was found stable for more than 6 months keeping its red color. Upon mixing with an aqueous solution of Ricinus communis agglutinin

• of the terminal chloride group in 2 with sodium azide afforded glycosyl azide 3. The thermal cycloaddition of the azide group to C60 was conducted by boiling in chlorobenzene to obtain a mixture of the three main products, which were identified as a mixture of [5,6]- and [6,6]-fused isomers of

Towards allosteric receptors – synthesis of β-cyclodextrin-functionalised 2,2’-bipyridines and their metal complexes

• Christopher Kremer,
• Gregor Schnakenburg and
• Arne Lützen

Beilstein J. Org. Chem. 2014, 10, 814–824, doi:10.3762/bjoc.10.77

• furnished 19 [30] which could by peracetylated into 20 [31] using acetic acid anhydride both in decent yields. Staudinger reduction of the azide group of 20 then afforded the desired monoaminated cyclodextrin 21 (Scheme 4). Finally, nucleophilic addition of 21 to the diisothiocyanato-2,2’-bipyridines 14–16

Synthesis of five- and six-membered cyclic organic peroxides: Key transformations into peroxide ring-retaining products

• Alexander O. Terent'ev,
• Dmitry A. Borisov,
• Vera A. Vil’ and
• Valery M. Dembitsky

Beilstein J. Org. Chem. 2014, 10, 34–114, doi:10.3762/bjoc.10.6

• cyclization occurs during the oxidation of 1,4-betaines 291a–d prepared from dienones 290a–d containing an azide group in the side chain. The reaction yields peroxide-bridged indolizinediones 292a–d (Scheme 82) [339]. 3.12. Structural modifications, in which 1,2-dioxane ring remains intact This section deals

Stereoselectively fluorinated N-heterocycles: a brief survey

• Xiang-Guo Hu and
• Luke Hunter

Beilstein J. Org. Chem. 2013, 9, 2696–2708, doi:10.3762/bjoc.9.306

• azide group to align gauche to the ring nitrogen. The situation was not greatly changed upon introduction of a (6S)-fluorine atom (compound 22): in this case, no single conformation of 22 was able to satisfy a C–F…N+ gauche alignment as well as the two conformational preferences described for 21. In

Synthesis of mucin-type O-glycan probes as aminopropyl glycosides

• David Benito-Alifonso,
• Rachel A. Jones,
• Anh-Tuan Tran,
• Hannah Woodward,
• Nichola Smith and
• M. Carmen Galan

Beilstein J. Org. Chem. 2013, 9, 1867–1872, doi:10.3762/bjoc.9.218

• reductively convert the N-Troc-protecting group to the corresponding amine, resulted in partial reduction of the azide group in the linker. We found that deacylation with LiOH gave better yields, cleaner reaction mixtures and moreover the conditions are compatible with other functionalities that are

• followed by reduction of the azide group in the linker by catalytic hydrogenolysis using hydrogen and Pd/C to give trisaccharide 7 in 52% yield, after the 5 step unmasking sequence. Conclusion A highly convergent and stereoselective strategy has been used to access mucin-type glycan targets 1–7. The

A construction of 4,4-spirocyclic γ-lactams by tandem radical cyclization with carbon monoxide

• Mitsuhiro Ueda,
• Yoshitaka Uenoyama,
• Nozomi Terasoma,
• Shoko Doi,
• Shoji Kobayashi,
• Ilhyong Ryu and
• John A. Murphy

Beilstein J. Org. Chem. 2013, 9, 1340–1345, doi:10.3762/bjoc.9.151

• -lactams in which CO was introduced as the lactam carbonyl moiety [17][18][19][20][21][22][23]. Our approach consists of a sequence of aryl radical cyclization, radical carbonylation [24][25][26][27], and spirocyclization of the resulting acyl radical onto an azide group, which can give 4,4-spirocyclic γ

• radical A gives an alkyl radical B, which adds to CO to give an acyl radical C. Finally, the 5-exo addition of acyl radical C onto an azide group takes place with the liberation of dinitrogen to give a cyclized amidyl radical D [29][30], which abstracts hydrogen from TTMSS, affording the 4,4-spirocyclic

A versatile and efficient approach for the synthesis of chiral 1,3-nitroamines and 1,3-diamines via conjugate addition to new (S,E)-γ-aminated nitroalkenes derived from L-α-amino acids

• Vera Lúcia Patrocinio Pereira,
• André Luiz da Silva Moura,
• Daniel Pais Pires Vieira,
• Leandro Lara de Carvalho,
• Eliz Regina Bueno Torres and
• Jeronimo da Silva Costa

Beilstein J. Org. Chem. 2013, 9, 832–837, doi:10.3762/bjoc.9.95

• -derivatives 10b,c (Table 1, entries 11 and 12) or the triazole derivative 11a (Table 1, entry 13) when THF or CH3CN were used as solvents, respectively. The formation of chiral 1,2,3-triazole derivative 11a was proposed to be by way of a [3 + 2]-cycloaddition with the azide group acting as 1,3-dipolarophile

Synthesis of heteroglycoclusters by using orthogonal chemoselective ligations

• Baptiste Thomas,
• Michele Fiore,
• Isabelle Bossu,
• Pascal Dumy and
• Olivier Renaudet

Beilstein J. Org. Chem. 2012, 8, 421–427, doi:10.3762/bjoc.8.47

• propargyl [41] glycosides 1-3 (Figure 1) and the cyclopeptide 4 (Scheme 1). This scaffold containing two lysines (Lys) functionalized with an aldehyde and two norleucines (Nle) bearing an azide group was prepared by using a strategy adapted from the procedure described previously [42]. In the first step

Synthesis of 2-amino-3-arylpropan-1-ols and 1-(2,3-diaminopropyl)-1,2,3-triazoles and evaluation of their antimalarial activity

• Matthias D’hooghe,
• Stéphanie Vandekerckhove,
• Karen Mollet,
• Karel Vervisch,
• Stijn Dekeukeleire,
• Liesbeth Lehoucq,
• Carmen Lategan,
• Peter J. Smith,
• Kelly Chibale and
• Norbert De Kimpe

Beilstein J. Org. Chem. 2011, 7, 1745–1752, doi:10.3762/bjoc.7.205

• substrates to perform “click chemistry” [34] incorporate an azide group and an aziridine ring in their structure, for example in 2-(azidomethyl)aziridines, thus providing a direct access to 2-[(1,2,3-triazol-1-yl)methyl]aziridines through Cu-catalyzed reaction with alkynes [35]. In this work, nonactivated N

Functionalization of heterocyclic compounds using polyfunctional magnesium and zinc reagents

• Paul Knochel,
• Matthias A. Schade,
• Sebastian Bernhardt,
• Georg Manolikakes,
• Albrecht Metzger,
• Fabian M. Piller,
• Christoph J. Rohbogner and
• Marc Mosrin

Beilstein J. Org. Chem. 2011, 7, 1261–1277, doi:10.3762/bjoc.7.147

• functionality to an azide group is readily achieved by treating 81 with NaN3/BF3·OEt2-CF3CO2H in CH2Cl2 leading to the aryl azide 82 in 78% yield. Heating of 82 in mesitylene at reflux for 6 h provides ellipticine 83, a potent antitumor agent in 57% yield (Scheme 14) [42]. The structural variations of

Calix[4]arene-click-cyclodextrin and supramolecular structures with watersoluble NIPAAM-copolymers bearing adamantyl units: “Rings on ring on chain”

• Bernd Garska,
• Monir Tabatabai and
• Helmut Ritter

Beilstein J. Org. Chem. 2010, 6, 784–788, doi:10.3762/bjoc.6.83

• -dipropargylether-26,28-hydroxy-calix[4]arene (calix[4]arene-1,3-dipropargylether) (2) onto 6I-azido-6I-deoxycyclomaltoheptaose (3) was proven by IR spectroscopy by the disappearance of the bands for the azide group at 2105 cm−1 and for the propargyl group at 2115 cm−1, whilst the formation of the triazole ring was

Synthetic incorporation of Nile Blue into DNA using 2′-deoxyriboside substitutes: Representative comparison of (R)- and (S)-aminopropanediol as an acyclic linker

• Daniel Lachmann,
• Sina Berndl,
• Otto S. Wolfbeis and
• Hans-Achim Wagenknecht

Beilstein J. Org. Chem. 2010, 6, No. 13, doi:10.3762/bjoc.6.13

• visible spectrum) for use in “click” conjugation have been reported meanwhile [18]. The dye carrying the azide group was reacted with an alkyne group that was incorporated into the oligonucleotides as a nucleotide substituent. (S)-3-Amino-1,2-propanediol was used as an acyclic linker and substitute for

Functional properties of metallomesogens modulated by molecular and supramolecular exotic arrangements

• Alessandra Crispini,
• Mauro Ghedini and
• Daniela Pucci

Beilstein J. Org. Chem. 2009, 5, No. 54, doi:10.3762/bjoc.5.54

• depend on the size of the X group and on the dipole moment associated with the Pt-X bond, with the sequence, for the clearing points Clazide group which promoted a lowering of both transition temperatures. Moreover, these Pt(II) complexes revealed to be photoluminescent with a good degree