标题：Acid-promoted selective carbon-fluorine bond activation and functionalization of hexafluoropropene by nickel complexes supported with phosphine ligands
作者：Xu, W.;Sun, H.;Xiong, Z.;Li, X.
作者机构：[Xu, W] School of Chemistry and Chemical Engineering, Ministry of Education, Shandong University, Shanda Nanlu 27, 250100 Jinan, China;[ Sun, H] Schoo 更多
通讯作者地址：[Li, XY]Shandong Univ, Sch Chem & Chem Engn, Key Lab Special Funct Aggregated Mat, Minist Educ, Shanda Nanlu 27, Jinan 250100, Peoples R China.
关键词：Acid-promoted selective carbon-fluorine;bond activation and functionalization of;bond activation and functionalization
摘要：The electron-rich complex Ni(PMe_3)_4 was utilized to react with perfluoropropene to obtain Ni(CF_2=CFCF_3) (PMe_3)_3 (1). The selective C-F bond activation process of the π-coordinated perfluoropropene in 1 was conducted with the promotion of Lewis acids (ZnCl_2, LiBr, and LiI) under mild conditions to afford the products Ni(CF_3C=CF_2)(PMe_3)_2X (X = Cl (2), Br (3), I (4)). The structures of complexes 2 and 3 determined by X-ray single-crystal diffraction confirmed that the C-F bond activation occurred at the geminal position of the trifluoromethyl group. Surprisingly, CF _3COOH as a protonic acid could also carry out a similar activation reaction to give rise to Ni(CF_3C=CF_2)(CF _3COO)(PMe_3)_2 (7), while only the addition products Ni(CF_2CFHCF_3)(CH_3COO)(PMe_3) (5) and Ni(CF_2CFHCF_3)(CH_3SO _3)(PMe_3) (6) were obtained with CH_3COOH and CH_3SO_3H. The transmetalation products Ni(CF _3C=CF_2)Ph(PMe_3)_2 (8), Ni(CF _3C=CF_2)(p-MeOPh)(PMe_3)_2 (9), and Ni(CF_3C=CF_2)(CiCPh)(PMe_3)_2 (10) were obtained through the reactions of Ni(CF_3C=CF_2)(PMe _3)_2Cl (2) with PhMgBr, (p-MeOPh)MgBr, and PhC14;CLi. In contrast, the reaction of complex 2 with PhCH_2CH_2MgBr delivered complex 11, Ni(CF_3CH=C-CH_2CH_2Ph) (PMe_3)_2, via double C-F bond activation. All of the C(sp~2)-F bonds in complex 11 were activated and cleaved. The structures of complexes 5 and 7-11 were determined by X-ray single-crystal structure analysis. A reasonable mechanism was proposed and partially experimentally verified through operando IR and in situ ~1H NMR spectroscopy.