{"title":"Sc(III)催化羰基-炔反应合成非对映选择性烯:协同异步机制。","authors":"Xinya Yuan,Jiashen Yang,Shaozhong Wang","doi":"10.1021/acs.orglett.5c03172","DOIUrl":null,"url":null,"abstract":"The carbonyl-yne reaction, involving propargylic C-H bond cleavage for carbon-carbon bond formation, is significantly less developed than the classical Alder-ene reaction due to the linear geometry and relatively weak nucleophilicity of alkynes compared to alkenes. Herein, we report a Sc(OTf)3-catalyzed carbonyl-yne reaction enabling the diastereoselective synthesis of multisubstituted allenes from α-ketoamide-tethered alkynes with 100% atom economy and excellent diastereoselectivity (up to 20/1 dr). DFT calculations support a concerted, asynchronous mechanism involving C-C bond formation and propargylic C-H cleavage. Theoretical analysis suggests that the observed stereoselectivity arises from an interplay of electronic and entropic effects in the transition states.","PeriodicalId":54,"journal":{"name":"Organic Letters","volume":"75 1","pages":""},"PeriodicalIF":5.0000,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Sc(III)-Catalyzed Carbonyl-Yne Reaction for the Diastereoselective Allene Synthesis: A Concerted Asynchronous Mechanism.\",\"authors\":\"Xinya Yuan,Jiashen Yang,Shaozhong Wang\",\"doi\":\"10.1021/acs.orglett.5c03172\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The carbonyl-yne reaction, involving propargylic C-H bond cleavage for carbon-carbon bond formation, is significantly less developed than the classical Alder-ene reaction due to the linear geometry and relatively weak nucleophilicity of alkynes compared to alkenes. Herein, we report a Sc(OTf)3-catalyzed carbonyl-yne reaction enabling the diastereoselective synthesis of multisubstituted allenes from α-ketoamide-tethered alkynes with 100% atom economy and excellent diastereoselectivity (up to 20/1 dr). DFT calculations support a concerted, asynchronous mechanism involving C-C bond formation and propargylic C-H cleavage. Theoretical analysis suggests that the observed stereoselectivity arises from an interplay of electronic and entropic effects in the transition states.\",\"PeriodicalId\":54,\"journal\":{\"name\":\"Organic Letters\",\"volume\":\"75 1\",\"pages\":\"\"},\"PeriodicalIF\":5.0000,\"publicationDate\":\"2025-09-30\",\"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.5c03172\",\"RegionNum\":1,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"CHEMISTRY, ORGANIC\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Organic Letters","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1021/acs.orglett.5c03172","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, ORGANIC","Score":null,"Total":0}
Sc(III)-Catalyzed Carbonyl-Yne Reaction for the Diastereoselective Allene Synthesis: A Concerted Asynchronous Mechanism.
The carbonyl-yne reaction, involving propargylic C-H bond cleavage for carbon-carbon bond formation, is significantly less developed than the classical Alder-ene reaction due to the linear geometry and relatively weak nucleophilicity of alkynes compared to alkenes. Herein, we report a Sc(OTf)3-catalyzed carbonyl-yne reaction enabling the diastereoselective synthesis of multisubstituted allenes from α-ketoamide-tethered alkynes with 100% atom economy and excellent diastereoselectivity (up to 20/1 dr). DFT calculations support a concerted, asynchronous mechanism involving C-C bond formation and propargylic C-H cleavage. Theoretical analysis suggests that the observed stereoselectivity arises from an interplay of electronic and entropic effects in the transition states.
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.