{"title":"Direct synthesis of N-perfluoro-tert-butyl secondary amines from N-trifluoromethyl secondary amines","authors":"leibing Wang, Zhongyu Feng, Zhen Luo, Zihao Guo, Jieping Wang, WenBin Yi","doi":"10.1039/d4sc06335j","DOIUrl":null,"url":null,"abstract":"N-Perfluoro-tert-butyl (N-PFtB) secondary amines, harboring a unique 19F-reporting moiety linked directly to nitrogen, are highly attractive due to their diverse potential applications. However, their mild and facile synthesis remains a significant challenge. Herein, we present a safe and efficient strategy for the direct synthesis of N-perfluoro-tert-butyl secondary amines from readily available N-trifluoromethyl secondary amines. Experiments and theoretical calculations demonstrate that this novel protocol encompasses three main processes: the elimination of hydrogen fluoride from the N-trifluoromethyl precursor, consecutive addition-elimination conversion of difluoromethyl imine (R-N=CF2) to hexafluoropropyl imine (R-N=C(CF3)2), and final addition of R-N=C(CF3)2 with the in situ generated fluoroform (HCF3). Key advantages of this reaction include the utilization of a single trifluoromethyl source and the N-trifluoromethyl starting material itself as the hydrogen source. Notably, the elimination of hydrogen fluoride, facilitated by CsF, is critical for the success of this approach. This method is compatible with a broad range of functional groups, including heterocyclic compounds. 19F MRI experiments suggest promising prospects for PFtB-labeled secondary amines as 19F MRI contrast agents.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":null,"pages":null},"PeriodicalIF":7.6000,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemical Science","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1039/d4sc06335j","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
N-Perfluoro-tert-butyl (N-PFtB) secondary amines, harboring a unique 19F-reporting moiety linked directly to nitrogen, are highly attractive due to their diverse potential applications. However, their mild and facile synthesis remains a significant challenge. Herein, we present a safe and efficient strategy for the direct synthesis of N-perfluoro-tert-butyl secondary amines from readily available N-trifluoromethyl secondary amines. Experiments and theoretical calculations demonstrate that this novel protocol encompasses three main processes: the elimination of hydrogen fluoride from the N-trifluoromethyl precursor, consecutive addition-elimination conversion of difluoromethyl imine (R-N=CF2) to hexafluoropropyl imine (R-N=C(CF3)2), and final addition of R-N=C(CF3)2 with the in situ generated fluoroform (HCF3). Key advantages of this reaction include the utilization of a single trifluoromethyl source and the N-trifluoromethyl starting material itself as the hydrogen source. Notably, the elimination of hydrogen fluoride, facilitated by CsF, is critical for the success of this approach. This method is compatible with a broad range of functional groups, including heterocyclic compounds. 19F MRI experiments suggest promising prospects for PFtB-labeled secondary amines as 19F MRI contrast agents.
期刊介绍:
Chemical Science is a journal that encompasses various disciplines within the chemical sciences. Its scope includes publishing ground-breaking research with significant implications for its respective field, as well as appealing to a wider audience in related areas. To be considered for publication, articles must showcase innovative and original advances in their field of study and be presented in a manner that is understandable to scientists from diverse backgrounds. However, the journal generally does not publish highly specialized research.