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

Efficient continuous-flow synthesis of novel 1,2,3-triazole-substituted β-aminocyclohexanecarboxylic acid derivatives with gram-scale production

• Sándor B. Ötvös,
• Ádám Georgiádes,
• István M. Mándity,
• Lóránd Kiss and
• Ferenc Fülöp

Beilstein J. Org. Chem. 2013, 9, 1508–1516, doi:10.3762/bjoc.9.172

• applications in numerous other areas of modern chemical sciences, such as bioconjugation [13], supramolecular chemistry, [14] and polymer sciences [15]. Probably the most useful and powerful procedure for the synthesis of 1,2,3-triazoles is the Huisgen 1,3-dipolar cycloaddition of organic azides with

• emerged [59]. The main driving forces behind these CF methodologies are the safety aspects associated with the handling of azides and the inherent scalability of flow processing. Moreover, when organic azides are formed in situ, operational safety can be further improved [55][57]. We envisioned that it

Copper-catalyzed CuAAC/intramolecular C–H arylation sequence: Synthesis of annulated 1,2,3-triazoles

• Rajkumar Jeyachandran,
• Harish Kumar Potukuchi and
• Lutz Ackermann

Beilstein J. Org. Chem. 2012, 8, 1771–1777, doi:10.3762/bjoc.8.202

• catalytic efficacy. Subsequently, we explored the extension of this approach to the development of a chemoselective three-component one-pot reaction. Thus, we found that alkyl bromides 2 could be directly employed as user-friendly substrates for the in situ formation of the corresponding organic azides

Metal–ligand multiple bonds as frustrated Lewis pairs for C–H functionalization

• Matthew T. Whited

Beilstein J. Org. Chem. 2012, 8, 1554–1563, doi:10.3762/bjoc.8.177

• -metal (or "Roper-type") carbenes with significant π backbonding, consistent with Roper's predicted patterns of reactivity for metal–carbon double bonds [75]. These Roper-type carbenes also reacted with organic azides and nitrous oxide via an apparent [3 + 2] cycloaddition [76][77], leading to oxygen

• -atom or nitrene-group transfer and formation of (PNP)Ir–N2 [78], and this reaction was utilized in catalytic C–H functionalization (see below). More recently, Hillhouse's nickel carbenes and imides have been shown to exhibit similar reactivity with organic azides, though reaction with CO2 has not been

• catalytic cycle was ultimately achieved following the discovery that the reaction of (PNP)Ir═C(H)Ot-Bu with organic azides leads to the formation of tert-butyl formimidates and (PNP)Ir–N2, which is a suitable precursor for C–H activation of MTBE upon photolysis [78] (Scheme 15). Although the presence of

EPR and pulsed ENDOR study of intermediates from reactions of aromatic azides with group 13 metal trichlorides

• Giorgio Bencivenni,
• Riccardo Cesari,
• Daniele Nanni,
• Hassane El Mkami and
• John C. Walton

Beilstein J. Org. Chem. 2010, 6, 713–725, doi:10.3762/bjoc.6.84

• ]. Parallel to that, organic azides are increasingly used as sources of N-centred radicals, although most such methods also require organotin hydrides [17][18][19][20][21][22][23]. In seeking cleaner, less toxic and more efficient synthetic methodology – not reliant on organotin compounds [24][25][26][27][28

• ] – some of us began investigating the reactions of organic azides with dichloroindium hydride [29], allylindium dichloride [30], and other group 13 metal derivatives. These reagents smoothly convert aromatic and aliphatic azides into the corresponding amines, γ-azidonitriles into pyrrolidin-2-imines [29

• arrow indicating the magnetic field position of the ENDOR experiment. DFT structures and SOMOs for dimer and trimer radical cations. Organic azides studied. Reaction of 4-substituted-phenyl azides with GaCl3. Dimer and trimer radical cations. Possible mechanism of formation of aromatic amines. Possible

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

• ]. 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

Synthesis of coumarin or ferrocene labeled nucleosides via Staudinger ligation

• Ivana Kosiova,
• Andrea Janicova and
• Pavol Kois

Beilstein J. Org. Chem. 2006, 2, No. 23, doi:10.1186/1860-5397-2-23

• starting compounds for preparation of modified nucleosides are azidonucleosides. In general, organic azides are valuable, energy-rich and flexible intermediates, which can react very differently under various reaction conditions. [13] They can react at N1 with electrophiles (carbon electrophiles, protons