Phase-transfer-shuttle generated in situ enables novel S1-type fluorination of sulfonium ylide with hydrofluoric acid
作者机构:Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials Shanghai Institute of Organic Chemistry University of Chinese Academy Sciences Chinese Academy of Sciences
出 版 物:《Science China Chemistry》 (中国科学:化学(英文版))
年 卷 期:2024年
核心收录:
学科分类:081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 070303[理学-有机化学] 0703[理学-化学]
摘 要:The development of a nucleophilic fluorination protocol using hydrofluoric acid as the fluoride source represents a long-sought goal in the field of organofluorine chemistry. We report herein the realization of such a reaction that employed alkyl-substituted sulfonium ylides as the substrates. The key to the success of the protocol was attributed to two factors: First, as a Br?nsted base,the ylide was able to be protonated by HFaq, thus serving as a phase-transfer shuttle generated in situ to bring F-from aqueous phase to the organic phase promoting desolvation of fluoride ion. Second, after protonation, a sulfonium salt, a good leaving group, was generated and subsequent attacked by the fluoride to afford the alkyl fluoride. Mechanistic investigation indicates that the reaction occurs via an SN1 pathway. Because of the nature of the cationic intermediate in the reaction, two attractive rearrangement-fluorination approaches including 1,2-aryl migration fluorination and ring-expansion fluorination were disclosed.