Aims and Objectives: Benzoxazoles are valuable bicyclic aromatic compounds; the construction of
benzoxazoles via C-O cross-coupling reactions has attracted more and more attention.
Materials and Methods: The best condition of C-O bond formation from o-haloanilides was carried out, taking
Cu(OTf)2 (5 mol%) and vasicine (10 mol%) as the catalysts in EtOH in the presence of K2CO3 (2 eq.) for 12 h at
Results: A series of 2-substituted benzoxazoles have been prepared in high yields from 2-bromoanilides and 2-
iodioanilides under mild conditions.
Conclusion: We have developed an efficient Cu-vasicine catalytic system for intramolecular C-O bond formation.
This strategy is applicable to the synthesis of a wide variety of 2-substituted benzoxazoles by intramolecular
O-arylation of o-haloanilides.