An efficient method is described for the regioselective synthesis
of 1,4-disubstituted 1,2,3-triazoles (β-keto-1,2,3-triazoles)
in good to excellent yields by the successive treatment of secondary
alcohols with [hydroxy(tosyloxy)iodo]benzene (Koser’s reagent,
HTIB), sodium azide followed by copper(I) iodide catalyzed 1,3-dipolar
cycloaddition with terminal alkynes.
β-keto-1,2,3-triazoles - 1,3-dipolar cycloaddition
- secondary alcohols - α-tosyloxylation - copper iodide - terminal alkynes