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

• , Himachal Pradesh, 176 061, India 10.3762/bjoc.13.110 Abstract An efficient, eco-compatible diversity-oriented synthesis (DOS) approach for the generation of library of sugar embedded macrocyclic compounds with various ring size containing 1,2,3-triazole has been developed. This concise strategy involves

• attached through Cu-catalyzed azide–alkyne cycloaddition (CuAAC) reaction (couple phase). Noteworthy, herein we utilized the CuAAC reaction as a medium for coupling different building blocks assembled iteratively to generate a 1,2,3-triazole moiety. This 1,2,3-triazole moiety linked as a spacer due to its

Synthesis of ribavirin 2’-Me-C-nucleoside analogues

• Fanny Cosson,
• Aline Faroux,
• Jean-Pierre Baltaze,
• Jonathan Farjon,
• Régis Guillot,
• Jacques Uziel and
• Nadège Lubin-Germain

Beilstein J. Org. Chem. 2017, 13, 755–761, doi:10.3762/bjoc.13.74

• catalytic hydrogenolysis. The latter reaction simultaneously cleaves the benzyl and isopropylidene groups affording compound 2 as a single isomer [22]. In the case of 5-(2’-deoxy-2’-methyl-2’-fluoro-β-D-ribosyl)-1,2,3-triazole-4-carboxamide (3) the synthesis was more delicate as it is necessary to

• procedures for compounds 2, 5–7, and 10–18 are covered by the Ph.D. thesis of Fanny Cosson [22]. 5-(2’-C-Methyl-β-D-ribofuranosyl)-1,2,3-triazole-4-carboxamide (2) [22]: Through the solution of compound 7 (mixture of 7a and 7b, 0.49 g, 1.1 mmol) in anhydrous methanol (14 mL) was bubbled ammonia gas for 2 h

• at 0 °C. Then the mixture was stirred for 12 h at rt and concentrated in vacuum. The residue was purified by flash chromatography (EtOAc/cyclohexane, 3:7 to 1:0) affording the mixture of the corresponding 1-benzyl-4-(2’,3’-O-isopropylidene-2’-C-methyl-β-D-ribofuranosyl)-1,2,3-triazole-5-carboxamide

Ultrasound-promoted organocatalytic enamine–azide [3 + 2] cycloaddition reactions for the synthesis of ((arylselanyl)phenyl-1H-1,2,3-triazol-4-yl)ketones

• Gabriel P. Costa,
• Natália Seus,
• Juliano A. Roehrs,
• Raquel G. Jacob,
• Ricardo F. Schumacher,
• Thiago Barcellos,
• Rafael Luque and
• Diego Alves

Beilstein J. Org. Chem. 2017, 13, 694–702, doi:10.3762/bjoc.13.68

• have been used for this cycloaddition reaction [20][21][22][23][24][25][26][27][28][29]. Organocatalytic approaches based on β-enamine–azide or enolate–azide cycloadditions have been employed to synthesize 1,2,3-triazole scaffolds [30][31][32]. Depending on the organocatalyst employed, different

• -(phenylselanylmethyl)-1,2,3-triazole A (Se-TZ) demonstrated an antidepressant-like effect (Figure 1) [60]. In another example, 5-phenyl-1-(2-(phenylselanyl)phenyl)-1H-1,2,3-triazole-4-carbonitrile B (Se-TZCN) was reported to exhibit antioxidant activities in different in vitro assays (Figure 1) [36]. Selenanyl-quinone

• found to be amenable to a range of 1,3-diketones or aryl azidophenyl selenides, providing an efficient access to novel selenium-containing 1,2,3-triazole compounds in good to excellent yields, in a few minutes of reaction at room temperature. The protocol was extended to activated ketones and

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

• (Scheme 2). After 60 min of reaction, 1H NMR spectra of the obtained products (5a–c) were measured (Figure 3A). In the 1H NMR spectra of 5a and 5b, the protons assignable to 1,2,3-triazole linkages are observed at 8.5 and 9.4 ppm, respectively, which were consistent with the previous report [28]. These

New approaches to organocatalysis based on C–H and C–X bonding for electrophilic substrate activation

• Pavel Nagorny and
• Zhankui Sun

Beilstein J. Org. Chem. 2016, 12, 2834–2848, doi:10.3762/bjoc.12.283

• with halides (Ka ≈ 103–104 M−1 in acetone-d6). Not surprisingly, a higher number of hydrogen bonds with an anion correlated with the higher stability of the receptor/anion complex. 1,2,3-Triazole-based catalysts for the dearomatization of N-heteroarenes The Mancheno group recently explored triazole

• 1,2,3-triazole, ammonium and pyridinium based catalysts. While the asymmetric transformations catalyzed by chiral 1,2,3-triazoles are now well precedented, the feasibility of asymmetric transformations promoted by other types of chiral C–H hydrogen bond donors is yet to be demonstrated. Similarly

• the near future. Electrophile Activation by Hydrogen Bond Donors [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Early examples of C–H hydrogen bonds and their recent use in supramolecular chemistry [18][19][32][33][34]. Design of 1,2,3-triazole-based catalysts for trityl group transfer

Synthesis and characterization of benzodithiophene and benzotriazole-based polymers for photovoltaic applications

• Desta Gedefaw,
• Marta Tessarolo,
• Margherita Bolognesi,
• Mario Prosa,
• Renee Kroon,
• Wenliu Zhuang,
• Patrik Henriksson,
• Kim Bini,
• Ergang Wang,
• Michele Muccini,
• Mirko Seri and
• Mats R. Andersson

Beilstein J. Org. Chem. 2016, 12, 1629–1637, doi:10.3762/bjoc.12.160

• -difluoro-2H-benzo[d][1,2,3]triazole (Tz) have attracted much attention and effectively employed in BHJ PSCs due to their intrinsic advantages, potentials and versatility [14][15]. Thanks to the desirable properties such as structural rigidity, planarity, extended π-conjugation length and favorable

• , 0.23 mmol) and 4,7-bis(5-bromothiophen-2-yl)-2-(2-butyloctyl)-5,6-difluoro-2H-benzo[d][1,2,3]triazole (3, 0.15 g, 0.23 mmol) were dissolved in toluene (10 mL) and degassed with N2 gas for 10 minutes. Pd2(dba)3 (4.2 mg, 2 mol %) and P(o-tolyl)3 (6.3 mg, 9 mol %) were added and purged with nitrogen gas

• black solid (149 mg). Synthesis of PTzBDT-2 (4,8-Bis(4,5-dihexylthiophen-2-yl)benzo[1,2-b:4,5-b']dithiophene-2,6-diyl)bis(trimethylstannane) (2, 0.095 g, 0.147 mmol) and 4,7-bis(5-bromothiophen-2-yl)-2-(4-((2-butyloctyl)oxy)butyl)-5,6-difluoro-2H-benzo[d][1,2,3]triazole (3, 0.15 g, 0.147 mmol) were

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

• ) [7], we were interested in studying the effect of replacing the nucleobase by a 1,2,3-triazole moiety, linked to various substituents, with the aim to retain or modulate essential elements for enzyme recognition. Indeed, the assembly of the triazole ring with various substituents confers to the final

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

• : cycloaddition; copper catalyst; ethynylstibane; organic azide; 1,2,3-triazole; Introduction The 1,3-dipolar azide–alkyne cycloaddition (AAC) has been effective for the synthesis of a wide variety of 1,2,3-triazoles [1]. However, this reaction has some limitations such as the requirement of high temperature and

• ) using 5 mol % of various Cu catalysts under aerobic conditions in THF at 60 °C (Table 1, entries 1–9). The results showed that CuBr was the best catalyst and gave the highest yield of the expected 5-stibano-1,2,3-triazole 3a (Table 1, entry 2). The reaction without the Cu catalyst did not afford 3a

• product (Table 1, entry 7). Heating of 5-stibano-1,2,3-triazole 3a in the presence of Cu(OAc)2 (5 mol %) under aerobic conditions in THF at 60 °C for 3 h afforded 4 in 91% yield. Furthermore, heating of 1 without 2a under the same conditions did not give the phenylacetylene and the starting compound was

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

• Republic of China 10.3762/bjoc.12.85 Abstract A series of copper complexes (3–6) stabilized by 1,2,3-triazole-tethered N-heterocyclic carbene ligands have been prepared via simple reaction of imidazolium salts with copper powder in good yields. The structures of bi- and trinuclear copper complexes were

• 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

• , the easy synthesis and versatile coordination ability of 1,2,3-triazoles have led to an explosion of interest in coordination chemistry [21] and homogeneous catalysis [22][23][24][25][26]. Although a number of metal complexes containing 1,4-disubstituted-1,2,3-triazole ligands were well studied

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

• different azides, followed by the sequential Swern oxidation and Ohira–Bestmann homologation provided the ethynyltriazole intermediate 9, finally another CuAAC resulted in the formation of unsymmetrical 4,4'-bi(1,2,3-triazole)s 10 (Scheme 4). The synthesis of 5,5'-bitriazoles Originally, in the research of

Supramolecular chemistry: from aromatic foldamers to solution-phase supramolecular organic frameworks

• Zhan-Ting Li

Beilstein J. Org. Chem. 2015, 11, 2057–2071, doi:10.3762/bjoc.11.222

• -triazole foldamers. In 2008, several groups independently described that the intermolecular C–H····Cl− hydrogen bonding could induce benzene-linked 1,2,3-triazole oligomers to form folded or helical conformations [61][62][63]. Currently, this family of foldamers have found wide applications in anion

• binding and design of photo-active molecular devices [64][65][66]. We were interested in developing inherently folded structural patterns for aromatic oligotriazole backbones. In 2009, Yuanyuan Zhu established that 1,5-diphenyl-1,2,3-triazole formed an intramolecular six-membered C–H····OMe hydrogen bonds

• confine the rotation of one single bond, while for the latter, it would confine two single bonds. Jiang and Huc and co-workers successfully utilized the five-membered N–H···Cl hydrogen bond to construct quinoline amide-derived double helices [53]. C–H····X (X = OR, F) hydrogen bonding-driven 1,2,3

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

• pharmacophoric conjugates through CuAAC. Basically, these conjugates included cholesterol and 1,2,3-triazole moieties, while the third, the pharmacophore, was either a chalcone, a lipophilic residue or a carbohydrate tag. These compounds were successfully prepared in good yields and characterized by NMR, MS and

• conditions used to prepare compound 2. This step aimed to have an alkylating probe that might target nucleic acids or proteins in the tested biological systems. The 1,2,3-triazole-bridged bicholesterol 13 (Scheme 3) was prepared in excellent yield. The H-5 signal of triazole (1H NMR) also was observed as

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

• –tetrathiafulvalenes [14], porphyrin–cyanines [15], porphyrin–carotenes [16], porphyrin–arene diimide [17] and porphyrin–fluorocene or rhodamine [18] have also been synthesized in which the porphyrin unit acts as an electron acceptor. Recently, the 1,2,3-triazole scaffold has been successfully employed to connect

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

• –alkyne (KA2) coupling that proceeds efficiently with no additives such that an equivalent of water is the sole byproduct. This two-step sequence allows for the incorporation of tetrasubstituted carbons bearing amines at the 4-position of the 1,2,3-triazole core. The overall yield of this three-reaction

• (blue). KA2 coupling followed by tandem silyl deprotection and triazole formation. Silyl deprotection/click conditions applied to tert-butylacetylene. An identical yield is observed without TBAF. High overall yield of 1,2,3-triazole fully-substituted at the 4-position. Optimization of silyl deprotection

The synthesis of active pharmaceutical ingredients (APIs) using continuous flow chemistry

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2015, 11, 1194–1219, doi:10.3762/bjoc.11.134

• ). More recently, the Jamison group also reported upon a short flow synthesis of the antiepileptic agent rufinamide (95) [87]. The 1,2,3-triazole ring was prepared via a dipolar cycloaddition between an in situ generated benzylic azide and propiolamide (also prepared in situ), which by maintaining a low

Quarternization of 3-azido-1-propyne oligomers obtained by copper(I)-catalyzed azide–alkyne cycloaddition polymerization

• Shun Nakano,
• Akihito Hashidzume and
• Takahiro Sato

Beilstein J. Org. Chem. 2015, 11, 1037–1042, doi:10.3762/bjoc.11.116

• . Keywords: 3-azido-1-propyne oligomer; CuAAC polymerization; hydrodynamic radius; methyl iodide; pulse-field-gradient spin-echo NMR; quarternization; Introduction The copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC) efficiently yields 1,4-disubstituted-1,2,3-triazole from rather stable azides and

• chemistry [8][9][10][11][12] to materials science [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29], as well as polymer synthesis [30][31][32][33][34][35][36]. Most of these studies deal with the 1,2,3-triazole moiety just as a linker. However, since 1,2,3-triazole possesses a large

• dipole moment and aromaticity, 1,2,3-triazole itself may be a functional group. Polymers composed of dense 1,2,3-triazole moieties on the backbone are thus promising as functional materials. Recently, we have investigated the CuAAC polymerization of 3-azido-1-propyne (AP) using 3-bromo-1-propyne as a

C-5’-Triazolyl-2’-oxa-3’-aza-4’a-carbanucleosides: Synthesis and biological evaluation

• Roberto Romeo,
• Caterina Carnovale,
• Salvatore V. Giofrè,
• Maria A. Chiacchio,
• Adriana Garozzo,
• Emanuele Amata,
• Giovanni Romeo and
• Ugo Chiacchio

Beilstein J. Org. Chem. 2015, 11, 328–334, doi:10.3762/bjoc.11.38

• can interact with intracellular targets to induce cytotoxicity [28][29][30][31][32]. Several functionalities have been inserted as linkers on the 2’-oxa-3’-aza-4’a-carbanucleoside skeleton in order to confer novel mechanisms of action for nucleoside mimics: in this context, the 1,2,3-triazole unit

• , the 1,2,3-triazole motif is exceedingly stable to basic or acidic hydrolysis and interacts strongly with biological targets through hydrogen bonding to nitrogen atoms as well as through dipole–dipole and π-stacking interactions [39]. Recently, a synthetic approach towards 3-hydroxymethyl-5-(1H-1,2,3

• -triazol)-isoxazolidines 5 has been described [40]: the obtained compounds inhibit the growth of anaplastic and follicular human thyroid cancer cell lines, with IC50 values in the range of 3.87–8.76 μM. In the same context, novel 1,2,3-triazole-appended 2’-oxa-3’-azanucleoside analogs 6 were developed [41

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

• defined a 1,2,3-triazole containing linkage between two piperidine rings as the flexible joint F, which should be easily accessible by copper-catalyzed cycloaddition between an azide G and a terminal alkyne H (CuAAC, “Click” reaction) [16]. Primary alcohols I serve as “protected” azides accessible by

• linked by a flexible joint. The deciding feature of ARs is the equilibrium between two leading conformations: a straight (STR) and a folded (FOL) species. The joint contains a 1,2,3-triazole moiety and the synthesis was carried out by copper catalyzed alkyne/azide cycloaddition (CuAAC). To obtain ARs

The unexpected influence of aryl substituents in N-aryl-3-oxobutanamides on the behavior of their multicomponent reactions with 5-amino-3-methylisoxazole and salicylaldehyde

• Volodymyr V. Tkachenko,
• Elena A. Muravyova,
• Sergey M. Desenko,
• Oleg V. Shishkin,
• Svetlana V. Shishkina,
• Dmytro O. Sysoiev,
• Thomas J. J. Müller and
• Valentin A. Chebanov

Beilstein J. Org. Chem. 2014, 10, 3019–3030, doi:10.3762/bjoc.10.320

• -aminotetrazole [9], 5-aminopyrazoles [11], and 5-amino-1,2,3-triazole [12] have previously been investigated. In some cases when the reaction could proceed in two alternative pathways the conditions enabling to control the interaction direction were determined, which made it possible to obtain the desired

Synthesis and characterization of a new photoinduced switchable β-cyclodextrin dimer

• Florian Hamon,
• Claire Blaszkiewicz,
• Marie Buchotte,
• Estelle Banaszak-Léonard,
• Hervé Bricout,
• Sébastien Tilloy,
• Eric Monflier,
• Christine Cézard,
• Laurent Bouteiller,
• Christophe Len and
• Florence Djedaini-Pilard

Beilstein J. Org. Chem. 2014, 10, 2874–2885, doi:10.3762/bjoc.10.304

• ]. As an exception, Vargas et al. [29] described the synthesis of 1,2,3-triazole-linked azobenzene-cyclodextrin derivatives producing rather good yields but the photoisomerization and inclusion complex properties were not investigated. Here, we report an efficient preparation of a new bis-β-CD with

A small azide-modified thiazole-based reporter molecule for fluorescence and mass spectrometric detection

• Stefanie Wolfram,
• Hendryk Würfel,
• Stefanie H. Habenicht,
• Christine Lembke,
• Phillipp Richter,
• Eckhard Birckner,
• Rainer Beckert and
• Georg Pohnert

Beilstein J. Org. Chem. 2014, 10, 2470–2479, doi:10.3762/bjoc.10.258

• bioactive metabolites and selective labeling of proteins and other biomacromolecules. A common structural motif for such probes consists of a reporter that can be attached by copper(I)-catalyzed 1,2,3-triazole formation between terminal alkynes and azides to a reactive headgroup. Here we introduce the

Facile synthesis of 1-alkoxy-1H-benzo- and 7-azabenzotriazoles from peptide coupling agents, mechanistic studies, and synthetic applications

• Mahesh K. Lakshman,
• Manish K. Singh,
• Mukesh Kumar,
• Raghu Ram Chamala,
• Vijayender R. Yedulla,
• Domenick Wagner,
• Evan Leung,
• Lijia Yang,
• Asha Matin and
• Sadia Ahmad

Beilstein J. Org. Chem. 2014, 10, 1919–1932, doi:10.3762/bjoc.10.200

• ][1,2,3]triazole, via in situ formation of pyrrolidine enamines and Pd catalysis. Keywords: alkoxy; azabenzotriazole; benzotriazole; peptide-coupling; phosphonium; Introduction Benzotriazole derivatives are of importance in diverse contexts. As examples, in medicinal chemistry substituted benzotriazoles

• [29]. Although BOP did not react with MeOH in the absence of a base, in the presence of Cs2CO3 rapid formation of HMPA was observed and 1-methoxy-1H-benzotriazole (1-methoxy-1H-benzo[d][1,2,3]triazole) was isolated [29]. This evidence clearly showed that alcohols are capable of reaction with BOP in

• experiments gave poorer results with a lower amount of an alcohol, then reactions were conducted with higher excesses of the alcohol. Specific experimental and work-up details are provided under the individual compound headings. Representative examples 1-(1-Phenylethoxy)-1H-benzo[d][1,2,3]triazole (1e) The

Microwave-assisted Cu(I)-catalyzed, three-component synthesis of 2-(4-((1-phenyl-1H-1,2,3-triazol-4-yl)methoxy)phenyl)-1H-benzo[d]imidazoles

• Yogesh Kumar,
• Vijay Bahadur,
• Anil K. Singh,
• Virinder S. Parmar,
• Erik V. Van der Eycken and
• Brajendra K. Singh

Beilstein J. Org. Chem. 2014, 10, 1413–1420, doi:10.3762/bjoc.10.145

• several existing drugs. Various medicinal agents are composed of several heterocyclic rings in which the benzimidazole and the 1,2,3-triazole constitute an important position. Benzimidazole derivatives have been shown to posses anticancer [1][2], antihypertensive [3], antibacterial [4] and enzyme

Design and synthesis of multivalent neoglycoconjugates by click conjugations

• Feiqing Ding,
• Li Ji,
• Ronny William,
• Hua Chai and
• Xue-Wei Liu

Beilstein J. Org. Chem. 2014, 10, 1325–1332, doi:10.3762/bjoc.10.134

• construction of a 1,4-disubstituted-1,2,3-triazole unit via a copper(I)-catalyzed modern version of the Huisgen-type azide–alkyne cycloaddition [6][7][8][9][10] has been considered to be a powerful ligation method for glycoconjugation [11][12][13][14][15][16]. In addition to the simplicity of this reaction and

• the presence of 10 mol % of copper(I) iodide (Table 1, entry 4). The combination of CuSO4·5H2O (10 mol %) and sodium ascorbate (10 mol %) was found to be a suitable catalyst leading regiospecifically to the 1,4-disubstituted-1,2,3-triazole 4a with moderate yield of 46% in t-BuOH/H2O 1:1 after 20 hours

Advancements in the mechanistic understanding of the copper-catalyzed azide–alkyne cycloaddition

• Regina Berg and
• Bernd F. Straub

Beilstein J. Org. Chem. 2013, 9, 2715–2750, doi:10.3762/bjoc.9.308

• with quantitative conversion to give the 1,4-disubstituted 1,2,3-triazole exclusively. Common side reactions such as the Glaser coupling [9][10][11] are not observed. The presented reaction conditions are compatible with a variety of functional groups such as ester, ether, amide, thioether, Fmoc and

• , sulfonamide and amine substituents. The catalytic process is insensitive towards the presence of air and pH changes between pH 4 and 12 in a solvent mixture of water and tert-butanol. This strictly regioselective stepwise process gives the 1,4-disubstituted 1,2,3-triazole only and accelerates the reaction by

• , the azide substrates could be prepared in situ by reaction of the corresponding bromide with sodium azide. For example, the reaction of benzyl bromide with sodium azide and phenylacetylene in the presence of 2 mol % [(SIMes)CuBr] in water gave 86% 1-benzyl-4-phenyl-1H-1,2,3-triazole within 18 hours at