First successful synthesis, isolation and characterization of open-chain 1,2-diazidoethenes

1,2,3-Triazoles

“…Thus, the reaction of cyclooctyne with diazide 1061 carried out in CH 2 Cl 2 at room temperature is accomplished within 2 h and provides ditriazolyl derivative 1060 in 76% yield. A similar reaction of cyclooctyne with diazide 1062 leads to ditriazolyl derivative 1063 in 90% yield ( Scheme 175 ) <2005T8904> .

Scheme 175

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Hexadecyltributylphosphonium Azide - A Highly Potent Reagent for the Synthesis of Unusual Azides

“…59 When the 2-azido-3-prop-2-enals 42 were treated with QN 3 in chloroform, the desired products 43a and 43b were formed in excellent yields of 86% and 91%, respectively (Scheme 14). 63 This first synthesis of open-chain 1,2-diazidoethenes may run via the well-known additionelimination mechanism supported by the electron-withdrawing aldehyde unit. Such substitutions are known to usually proceed with retention of configuration at the carbon-carbon double bond.…”

Copper-Mediated Synthesis of (E)-1-Azido and (Z)-1,2-Diazido Alkenes from 1-Alkene-1,2-diboronic Esters: An Approach to Mono- and 1,2-Di-(1,2,3-Triazolyl)-Alkenes and Fused Bis-(1,2,3-Triazolo)-Pyrazines

“…2 They were usually prepared from electronwithdrawing group-substituted propargyl azides or 2-azido-3halo cinnamaldehydes. 3 The photolysis of these vicinal alkenyl diazides afforded at low temperature 2-azido-2H-azirines that decomposed to nitriles on prolonged irradiation or heating. 4 If alkenyl boronic acids and esters have been already employed as efficient precursors of the corresponding vinyl azides, 5,6 which in turn can be easily converted to triazoles, 7 1alkene-1,2-diboronic esters were never engaged in similar sequence despites the major interest of the resulting bis-triazoles.…”

“…3 C NMR (101 MHz, CDCl 3 ) δ 126.9, 112.5, 61.5, 30.7, 27.5, 26.0, 18.4, -5.2. IR (neat) ν 2955, 2929, 2893, 2080, 1654, 1471, 1387, 1343, 1283, 1256, 1101, 1007, 963, 832, 813, 774 cm -1 .…”