Highly efficient click reaction on water catalyzed by a ruthenium complex

Abstract

The highly efficient click reaction between terminal alkynes and azides has been achieved on water using ruthenium complex RuH₂(CO)(PPh₃)₃ as the catalyst, and the catalyst loading was decreased to 0.2 mol% on water from 5 mol% in organic solvent. The RuH₂(CO)(PPh₃)₃/H₂O system also catalyzed the one-pot click reaction of bromides, sodium azide and alkynes; in this process, azides formed in situ and then underwent a click reaction with alkynes. In both aqueous processes, 1,4-disubstituted 1,2,3-triazoles were obtained in 50–89% yield with high regioselectivity.