Multistep flow synthesis of vinyl azides and their use in the copper-catalyzed Huisgen-type cycloaddition under inductive-heating conditions

• Lukas Kupracz,
• Jan Hartwig,
• Jens Wegner,
• Sascha Ceylan and
• Andreas Kirschning

Beilstein J. Org. Chem. 2011, 7, 1441–1448, doi:10.3762/bjoc.7.168

• -type cycloadditions The copper-catalyzed Huisgen-type cycloaddition (CuAAC) is a general and useful method for the synthesis of 1,4-disubstituted-1,2,3-triazoles and is based on the 1,3-dipolar cycloaddition of alkynes and azides [28]. Besides Cu(I) sources also Cu(0) sources, such as copper wire [29

Novel synthesis of pseudopeptides bearing a difluoromethyl group by Ugi reaction and desulfanylation

• Jingjing Wu,
• Hui Li and
• Song Cao

Beilstein J. Org. Chem. 2011, 7, 1070–1074, doi:10.3762/bjoc.7.123

• ][30]. Recently, we reported a novel and general strategy for the construction of a difluoromethyl compound library, and we further illustrated this strategy by application to the synthesis of CF2H-bearing pseudopeptides and 1,2,3-triazoles through Ugi and click reaction, respectively [27][30]. In

Advances in synthetic approach to and antifungal activity of triazoles

• Kumari Shalini,
• Nitin Kumar,
• Sushma Drabu and
• Pramod Kumar Sharma

Beilstein J. Org. Chem. 2011, 7, 668–677, doi:10.3762/bjoc.7.79

• membered ring containing two carbon and three nitrogen atoms. Triazoles have two isomeric forms, i.e., 1,2,3-triazole (1) and 1,2,4-triazole (2) (Figure 1). Triazoles are basic aromatic heterocyclic compounds. 1,2,3-Triazoles are surprisingly stable compared to other organic compounds with three adjacent

• nitrogen atoms. However, flash vacuum pyrolysis at 500 °C leads to loss of molecular nitrogen (N2) to produce aziridine. Certain triazoles are relatively easy to cleave by ring–chain tautomerism. Synthesis of triazoles Substituted 1,2,3-triazoles can be produced by the azide–alkyne Huisgen cycloaddition in

• which an azide and an alkyne undergo a 1,3-dipolar cycloaddition reaction in the presence of a catalyst such as copper (Scheme 1) or ruthemium (Scheme 2) [27]. Some new synthetic methods for 1,2,3-triazoles are given below (Scheme 3, Scheme 4) [28][29]. Structure activity relationships have revealed

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

• ” ligation strategy has become an important strategy for postsynthetic labeling of DNA [12][13]. Huisgen described first the [2+3]-cycloaddition between alkynes and azides yielding 1,2,3-triazoles [14]. The utility of this reaction as a bioligation method has grown incredibly after Meldal [15] and – almost

Dimerization of propargyl and homopropargyl 6-azido- 6-deoxy- glycosides upon 1,3-dipolar cycloaddition

• Nikolas Pietrzik,
• Daniel Schmollinger and
• Thomas Ziegler

Beilstein J. Org. Chem. 2008, 4, No. 30, doi:10.3762/bjoc.4.30

• libraries of highly glycosylated peptides, some members of which were indeed shown to behave like oligosaccharide mimics capable to specifically bind lectins [1][4]. In order to increase the structural diversity of the aforementioned building blocks, we contemplated using as the spacer entity 1,2,3

• -triazoles which are known to be easily generated through a copper-catalyzed 1,3-dipolar cycloaddition of an organic azide and an alkynyl derivative (Click Reaction) [5][6][7]. For review articles on copper-catalyzed Click Reactions see references [8][9][10][11]. Recently, we applied this approach to a

Synthesis of new triazole- based trifluoromethyl scaffolds

• Michela Martinelli,
• Thierry Milcent,
• Sandrine Ongeri and
• Benoit Crousse

Beilstein J. Org. Chem. 2008, 4, No. 19, doi:10.3762/bjoc.4.19

• derivatives to afford 1,4-disubstituted 1,2,3-triazoles through a Huisgen 1,3-dipolar cycloaddition. The reaction is catalyzed by a Cu(I) species in acetonitrile, and the corresponding products are obtained in good yields. This process thus offers an entry to new trifluoromethyl peptidomimetics as interesting

• peptidomimetics has been widely reported [6], the application of 1,2,3-triazoles in the field of conformational studies has occurred only recently [7][8][9][10][11][12][13]. In particular, Angelo and co-workers [8][12] reported the synthesis of triazole foldamers able to adopt specific protein-like conformations

• ]. The copper(I)-catalyzed 1,3-dipolar cycloaddition [33][34][35][36][37][38] of organic azides and alkynes (also called “click chemistry”) resulting in the formation of 1,2,3-triazoles has become an increasingly attractive area [39]. According to the literature [33][34][35][36][37][38], the Cu(I

2-Arylhydrazononitriles as building blocks in heterocyclic synthesis: A novel route to 2-substituted- 1,2,3-triazoles and 1,2,3-triazolo[4,5-b]pyridines

• Saleh M. Al-Mousawi and
• Moustafa Sh. Moustafa

Beilstein J. Org. Chem. 2007, 3, No. 12, doi:10.1186/1860-5397-3-12

• . Instead the hydrolyzed product 5 was formed. Introduction Interest in 1,2,3-triazole chemistry has recently been revived. [1][2][3][4] Zaprinast (1) is used as cyclic AMP phosphodiasterase inhibitor. [5] Plenty of 1,2,3-triazoles have also been reported to have useful pharmaceutical potential. [6][7][8

• refluxing 2a with hydroxylamine hydrochloride in DMF/piperidine afforded 1,2,3-triazoles whose structure was established by X-ray crystal structure. [11] On the other hand reacting 2b with hydroxylamine hydrochloride in DMF/piperidine afforded 5-amino-1,2,4-triazole via a rare Tiemann-like rearrangement. In

• that can be assigned as 1,2,4-oxadiazolylphenylhydrazone structure 4 or the isomeric acetylamino-1,2,3-triazole structure 6. Phenylhydrazono-1,2,4-oxadiazoles have been reported to rearrange thermally into acylamino-1,2,3-triazoles. [12] Compound 5 could be obtained via refluxing 3 in DMF in the