Divergent Synthesis of F- and CF 3 -Containing N-Fused Heterocycles Enabled by Fragmentation Cycloaddition of β-CF 3 -1,3-Enynes with N-Aminopyridiniums Ylides

作者：Xiaotian Shi, Qiong Wang, Zhiqing Tang, Hui‐Lin Huang, Tongxin Cao, Hua Cao, Xiang Liu · 发表于：Organic Letters · 年份：2024 · DOI：10.1021/acs.orglett.4c00088 · 被引用次数：30 · 研究领域：Fluorine in Organic Chemistry、Cyclopropane Reaction Mechanisms、Catalytic C–H Functionalization Methods

The two novel cyclization modes of β-CF 3 -1,3-enynes are presented herein for the divergent construction of F- and CF 3 -containing N-fused heterocycles. Fluorinated pyrazolo[1,5- a ]pyridines were afforded from β-CF 3 -1,3-enynes with N-aminopyridiniums ylides via detrifluoromethylative [2 + 3] cyclizations, followed by fluorine transfer from a CF 3 unit. Whereas reaction with N-aminoisoquinoliniums ylides gave CF 3 -substituted pyrrolo[2,1- a ]isoquinoline by unprecedented fragmentation [3 + 2]-cycloadditions. Additionally, gram-scale experiments and synthetic utility are demonstrated by further derivatization of fluorinated heterocycles.