Synthesis of Benzoxazoles from 2-Aminophenols and β-Diketones Using a Combined Catalyst of Brønsted Acid and Copper Iodide
摘要:
Cyclization reactions of 2-aminophenols with beta-diketones catalyzed by a combination of Bronsted acid and CuI are presented. Various 2-substituted benzoxazoles were obtained through these reactions. Different substituents such as methyl, chloro, bromo, nitro, and methoxy on 2-aminophenol are tolerated under the optimized reaction conditions.
Synthesis of Benzoxazoles from 2-Aminophenols and β-Diketones Using a Combined Catalyst of Brønsted Acid and Copper Iodide
作者:Muhammad Shareef Mayo、Xiaoqiang Yu、Xiaoyu Zhou、Xiujuan Feng、Yoshinori Yamamoto、Ming Bao
DOI:10.1021/jo500604x
日期:2014.7.3
Cyclization reactions of 2-aminophenols with beta-diketones catalyzed by a combination of Bronsted acid and CuI are presented. Various 2-substituted benzoxazoles were obtained through these reactions. Different substituents such as methyl, chloro, bromo, nitro, and methoxy on 2-aminophenol are tolerated under the optimized reaction conditions.
Unexpected Cascade Reactions of
<i>Ortho</i>
‐Hydroxyenaminones and β,γ‐Unsaturated α‐Ketoesters to Access Hydrogenated Benzoxazolepolycycles and Pyrrole−Phenol Atropisomers
作者:Xuguan Bai、Lele Wang、Ziying Zhang、Kuan Zhang、Zhanwei Bu、Yufeng Wu、Wenjing Zhang、Qilin Wang
DOI:10.1002/adsc.201900950
日期:2019.11.5
BF3 ⋅ OEt2‐catalyzed Michael addition/cyclization/dehydration sequence of ortho‐hydroxyenaminones with aromatic or aliphatic aldehyde‐derived β,γ‐unsaturated α‐ketoesters has been achieved to afford a wide range of fused hydrogenated benzoxazole polycycles in 67–95% yields in a highlydiastereoselective manner. When isatin‐derived β,γ‐unsaturated α‐ketoesters were employed as substrates, completely different reactivities