Elmira F. Khusnutdinova*, Paul Bremond, Anastasiya V. Petrova, Olga S. Kukovinets and Oxana B. Kazakova Pages 743 - 747 ( 5 )
A series of lupane C19-(1,2,3-triazolyl)-triterpenoids were obtained by “click” reaction of 3,28-diacetoxy-29-norlup- 20(30)-yne with different aromatic and sugar azides after screening of several copper-based catalytic systems. DFT calculations were performed (B3LYP/6.311 level of theory) and showed that the alkyne moiety is hindered by the triterpenoid skeleton, thus explaining its low reactivity and the requirement of a very active catalytic system. Ultimately, it was found that the dinuclear copper complex [Cu(µ-OH)(TMEDA)]2Cl2 is the most efficient catalyst. Moreover, for the first time, a bis-(triazolyltriterpenoid)-derivative was obtained by the reaction of lupane C19-alkyne with 1,4-bis(azidomethyl)benzene using the same catalyst.
Triterpenoids, betulin, lupanes, 1, 2, 3-triazoletriterpenes, “click” reaction, C19-(1, 2, 3-triazolyl)-lupanes.
Ufa Institute of Chemistry of the Russian Academy of Sciences. Box: 71, pr. Oktyabrya, 450054, Ufa, Aix Marseille Univ, CNRS, INSERM, Institut Paoli-Calmettes, CRCM, Marseille, Ufa Institute of Chemistry of the Russian Academy of Sciences, 71, pr. Oktyabrya, 450054 Ufa, Bashkir State University, 32, Validy Str., 450076, Ufa, Ufa Institute of Chemistry of the Russian Academy of Sciences, 71, pr. Oktyabrya, 450054 Ufa