Transition-Metal-Free Hydroamination/Defluorination/Cyclization of Perfluoroalkyl Alkynes with Amidines

Li-Wen Sun,^a Zi-Lun Yu,^a Xin-Long Luo,^a Mengtao Ma,^b Zhi-Liang Shen,*^a and Xue-Qiang Chu*^a

^a Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China.

^b Department of Chemistry and Materials Science, College of Science, Nanjing Forestry University, Nanjing 210037, China.

Abstract: An efficient defluorinative net-[3 + 3]-cyclization strategy for the construction of perfluoroalkyl-substituted pyrimidine derivatives by using a series of perfluoroalkyl alkynes and amidines as starting materials was developed. The present reaction proceeded successfully under metal-free conditions to form two new C-N bonds and a new heterocyclic ring through a sequence of hydroamination, defluorination, and annulation. The desired pyrimidines could be obtained with good functional group tolerance and moderate to good yields. Moreover, the distinctive fluorine effects of perfluoroalkyl substituents are vital for tuning the reactivity of alkynes for the anticipated defluorinative annulation. The pendant π system would lower associated bond dissociation energy significantly than that of a nonactivated C(sp³)-F bond.

Org. Chem. Front. 2022, 9, 109–116. (Impact factor: 5.281)

论文链接：https://pubs.rsc.org/en/Content/ArticleLanding/2021/QO/D1QO01439K