Ning Zou, Yu-Zheng Wu, Zi-Wei Shang, Yu-Wei Cao, Li-Min Liao, Cui Wei, Dong-Liang Mo, Wen-Jun Zhou
{"title":"Asymmetric [3 + 3] cycloaddition of cinnamaldehyde-derived <i>N</i>-aryl nitrones with 2-indolemethanols enabled by chiral phosphoric acid.","authors":"Ning Zou, Yu-Zheng Wu, Zi-Wei Shang, Yu-Wei Cao, Li-Min Liao, Cui Wei, Dong-Liang Mo, Wen-Jun Zhou","doi":"10.1039/d4ob01365d","DOIUrl":null,"url":null,"abstract":"<p><p>We described a chiral phosphoric acid (CPA) catalyzed asymmetric [3 + 3] cycloaddition of cinnamaldehyde-derived <i>N</i>-aryl nitrones with 2-indolylmethanols to prepare various indole-fused 1,2-oxazines in high yields (up to 96%) with excellent enantioselectivity (>99% ee). Control experiments indicate that hydrogen bonding plays important roles in controlling the enantioselectivity of products. This strategy provides an efficient pathway to construct enantioenriched indole-fused 1,2-oxazines from <i>N</i>-aryl nitrones with 2-indolylmethanols.</p>","PeriodicalId":96,"journal":{"name":"Organic & Biomolecular Chemistry","volume":null,"pages":null},"PeriodicalIF":2.9000,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Organic & Biomolecular Chemistry","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1039/d4ob01365d","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, ORGANIC","Score":null,"Total":0}
引用次数: 0
Abstract
We described a chiral phosphoric acid (CPA) catalyzed asymmetric [3 + 3] cycloaddition of cinnamaldehyde-derived N-aryl nitrones with 2-indolylmethanols to prepare various indole-fused 1,2-oxazines in high yields (up to 96%) with excellent enantioselectivity (>99% ee). Control experiments indicate that hydrogen bonding plays important roles in controlling the enantioselectivity of products. This strategy provides an efficient pathway to construct enantioenriched indole-fused 1,2-oxazines from N-aryl nitrones with 2-indolylmethanols.