Sankar Bharani , Biddika Ananda Rao , L. Raju Chowhan , Raghavaiah Pallepogu , Madavi S. Prasad
{"title":"Asymmetric synthesis of spiro[benzofuran-pyrrolidine]-indolinedione via bifunctional urea catalyzed [3 + 2]-annulation†","authors":"Sankar Bharani , Biddika Ananda Rao , L. Raju Chowhan , Raghavaiah Pallepogu , Madavi S. Prasad","doi":"10.1039/d4ob01614a","DOIUrl":null,"url":null,"abstract":"<div><div>In this study, we unveil a highly enantioselective [3 + 2] annulation protocol, adept at merging <em>N</em>-2,2,2-trifluoroethylisatin ketimines with 3-alkylidene benzofuranones under quinine-derived urea catalysis. This strategy furnishes complex spiro[benzofuran-pyrrolidine]indolinedione architectures, featuring strategically positioned trifluoromethyl groups of considerable pharmacological significance. The method distinguishes itself by employing minimal catalyst loadings while ensuring energy efficiency and accommodating a broad spectrum of substrates, resulting in excellent yields and exceptional stereocontrol (38 examples, up to 98% yield, up to >20 : 1 dr, and up to 99 : 1 er). Mechanistic investigations, underpinned by SC-XRD and NMR NOE analyses, elucidate the stereochemical pathways driving selectivity, while a comprehensive evaluation of electronic and steric substituent effects further refines the reaction's scope.</div></div>","PeriodicalId":96,"journal":{"name":"Organic & Biomolecular Chemistry","volume":"23 4","pages":"Pages 914-919"},"PeriodicalIF":2.9000,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Organic & Biomolecular Chemistry","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/org/science/article/pii/S1477052024010553","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
In this study, we unveil a highly enantioselective [3 + 2] annulation protocol, adept at merging N-2,2,2-trifluoroethylisatin ketimines with 3-alkylidene benzofuranones under quinine-derived urea catalysis. This strategy furnishes complex spiro[benzofuran-pyrrolidine]indolinedione architectures, featuring strategically positioned trifluoromethyl groups of considerable pharmacological significance. The method distinguishes itself by employing minimal catalyst loadings while ensuring energy efficiency and accommodating a broad spectrum of substrates, resulting in excellent yields and exceptional stereocontrol (38 examples, up to 98% yield, up to >20 : 1 dr, and up to 99 : 1 er). Mechanistic investigations, underpinned by SC-XRD and NMR NOE analyses, elucidate the stereochemical pathways driving selectivity, while a comprehensive evaluation of electronic and steric substituent effects further refines the reaction's scope.
期刊介绍:
Organic & Biomolecular Chemistry is an international journal using integrated research in chemistry-organic chemistry. Founded in 2003 by the Royal Society of Chemistry, the journal is published in Semimonthly issues and has been indexed by SCIE, a leading international database. The journal focuses on the key research and cutting-edge progress in the field of chemistry-organic chemistry, publishes and reports the research results in this field in a timely manner, and is committed to becoming a window and platform for rapid academic exchanges among peers in this field. The journal's impact factor in 2023 is 2.9, and its CiteScore is 5.5.