{"title":"Electroredox N-Heterocyclic Carbene-Catalyzed Enantioselective (3 + 3) Annulation of Enals with 2-Naphthols","authors":"Vikas Kale, Sayan Shee, Shiv Dutt, Nidhi Sinha, Akkattu T. Biju, Prabal Banerjee","doi":"10.1021/acs.orglett.4c03879","DOIUrl":null,"url":null,"abstract":"Developing asymmetric transformations using electroredox and N-heterocyclic carbene (NHC)-catalyzed radical pathways is still desirable and challenging. Herein, we report an iodide-promoted β-carbon activation (LUMO-lowering process) of enals via electroredox carbene catalysis coupled with a hydrogen evolution reaction (HER). This strategy offers an environmentally friendly and sustainable route for rapidly assembling synthetically useful chiral naphthopyran-3-one in good to excellent yield and enantioselectivity using traceless electrons as inexpensive and greener oxidants. The mechanistic studies and cyclic voltammetry suggest that the reaction proceeds via direct single electron transfer (SET) of the in situ-generated Breslow intermediate.","PeriodicalId":54,"journal":{"name":"Organic Letters","volume":"23 1","pages":""},"PeriodicalIF":4.9000,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Organic Letters","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1021/acs.orglett.4c03879","RegionNum":1,"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
Developing asymmetric transformations using electroredox and N-heterocyclic carbene (NHC)-catalyzed radical pathways is still desirable and challenging. Herein, we report an iodide-promoted β-carbon activation (LUMO-lowering process) of enals via electroredox carbene catalysis coupled with a hydrogen evolution reaction (HER). This strategy offers an environmentally friendly and sustainable route for rapidly assembling synthetically useful chiral naphthopyran-3-one in good to excellent yield and enantioselectivity using traceless electrons as inexpensive and greener oxidants. The mechanistic studies and cyclic voltammetry suggest that the reaction proceeds via direct single electron transfer (SET) of the in situ-generated Breslow intermediate.
期刊介绍:
Organic Letters invites original reports of fundamental research in all branches of the theory and practice of organic, physical organic, organometallic,medicinal, and bioorganic chemistry. Organic Letters provides rapid disclosure of the key elements of significant studies that are of interest to a large portion of the organic community. In selecting manuscripts for publication, the Editors place emphasis on the originality, quality and wide interest of the work. Authors should provide enough background information to place the new disclosure in context and to justify the rapid publication format. Back-to-back Letters will be considered. Full details should be reserved for an Article, which should appear in due course.