Facile and efficient one-pot synthesis of 2-arylbenzoxazoles using hydrogen tetrachloroaurate as catalyst under oxygen atmosphere.
In this paper, we presented a novel method for the facile and efficient one-pot synthesis of 2-arylbenzoxazoles, which were directly synthesized from 2-aminophenol and aldehydes catalyzed by hydrogen tetrachloroaurate (HAuCl(4).4H(2)O) under an oxygen atmosphere with anhydrous tetrahydrofuran (THF) as solvent or in solvent-free condition. The results show that this method could bring excellent yields as high as 96%. THF was proven to be the best choice among several solvents screened and the reaction was tolerated with a variety of aromatic aldehydes possessing electron-donating or withdrawing groups. The advantages of the present method lie in catalytic process using economic and environmentally benign dioxygen as oxidant.
Liu
Yun-kui
YK
State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology, Hangzhou 310014, China. ykuiliu@zjut.edu.cn
Mao
Da-jie
DJ
Lou
Shao-jie
SJ
Qian
Jian-qiang
JQ
Xu
Zhen-yuan
ZY
D000447:Aldehydes / Q000737:chemistry*; D000627:Aminophenols / Q000737:chemistry*; D002384:Catalysis; D002712:Chlorides / Q000737:chemistry*; D017612:Gold Compounds / Q000737:chemistry*; D010080:Oxazoles / Q000138:chemical synthesis*; D010100:Oxygen / Q000737:chemistry*
D000447:Aldehydes; D000627:Aminophenols; D002712:Chlorides; D017612:Gold Compounds; D010080:Oxazoles; C027667:2-aminophenol; C024568:gold tetrachloride, acid; D010100:Oxygen