"Click" synthesis of nonsymmetrical bis(1,2,3-triazoles).
Unsymmetrically 1,1'-disubstituted 4,4'-bis-1H-1,2,3-triazoles 4 have been prepared from 4-ethynyl-1,2,3-triazoles 5 and azides. Following a "double-click" strategy, two complementary approaches were implemented for the preparation of the key 4-ethynyltriazole intermediates 5: (a) the stepwise Swern oxidation/Ohira-Bestman alkynylation of readily available 4-hydroxymethyl-1,2,3-triazoles 8 and (b) the stepwise cycloaddition of TMS-1,4-butadiyne 9. The method is highlighted by its compatibility with orthogonally protected and functionalized saccharide-peptide hybrids and its ability to be extended to the trisubstituted counterparts 12.
Aizpurua
Jesus M
JM
Departamento de Química Orgánica-I, Universidad del País Vasco, Joxe Mari Korta R&D Center, Avda Tolosa-72, 20018 San Sebastián, Spain. jesusmaria.aizpurua@ehu.es
Azcune
Itxaso
I
Fratila
Raluca M
RM
Balentova
Eva
E
Sagartzazu-Aizpurua
Maialen
M
Miranda
Jose I
JI
D015394:Molecular Structure; D013237:Stereoisomerism; D014230:Triazoles / Q000138:chemical synthesis* / Q000737:chemistry
D014230:Triazoles