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Current Organic Synthesis


ISSN (Print): 1570-1794
ISSN (Online): 1875-6271

Research Article

Cu(II)/Vasicine Promoted Intramolecular C-O Formation: Synthesis of Benzoxazoles in EtOH

Author(s): Minxin Li, Meiling Li, Yanling Tang, Yun Sun*, Lu Qu and Zewei Mao*

Volume 18 , Issue 3 , 2021

Published on: 09 November, 2020

Page: [310 - 315] Pages: 6

DOI: 10.2174/1570179417666201109151752

Price: $65


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 90°C.

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.

Keywords: Cu(II)-vasicine, intramolecular O-arylation, o-haloanilides, benzoxazoles, EtOH, cross-coupling reactions.

Graphical Abstract
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