Divergent Reactions of
<scp>2‐Aminophenol</scp>
with
<scp>α‐Bromoacetate</scp>
: Asymmetric Synthesis of Two Regioisomeric 1,
<scp>4‐Benzoxazinones</scp>
作者:Seo Yun Kim、Gun Hee Han、Su Kyung Hong、Jieun Park、Yong Sun Park
DOI:10.1002/bkcs.12165
日期:2021.2
2‐Aminophenol displays a diverse pattern of reactivity in the substitution reaction of α‐bromoacetate. The substitution under neutral or basic conditions results in the formation of 1,4‐benzoxazinones, whereas Lewis acid‐promoted substitution leads to Friedel–Crafts alkylation of 2‐aminophenol. Asymmetric synthesis of two regioisomeric 1,4‐benzoxazinones is accomplished from the nucleophilic substitution
2-氨基苯酚在α-溴乙酸酯的取代反应中表现出不同的反应模式。在中性或碱性条件下的取代导致形成1,4-苯并恶嗪酮,而路易斯酸促进的取代导致2-氨基苯酚的Friedel-Crafts烷基化。在不同的反应条件下,用N-烷基-2-氨基苯酚将高度非对映异构富集的α-芳基-α-溴乙酸酯进行亲核取代,即可完成两个区域异构的1,4-苯并恶嗪酮的不对称合成。