Selective C–F and C–H Activation of Fluoroarenes by Fe(PMe<sub>3</sub>)<sub>4</sub> and Catalytic Performance of Iron Hydride in Hydrosilylation of Carbonyl Compounds
作者:Tingting Zheng、Junye Li、Shumiao Zhang、Benjing Xue、Hongjian Sun、Xiaoyan Li、Olaf Fuhr、Dieter Fenske
DOI:10.1021/acs.organomet.6b00546
日期:2016.10.24
The reactions of perfluorinated toluene (CF3C6F5), pentafluoropyridine (C5NF5), and hexafluorobenzene (C6F6) with the iron(0) complex Fe(PMe3)(4) were investigated. The Fe(I) complexes (4-CF3C6F4)Fe(PMe3)(4) (1), (4- C5NF4)Fe(PMe3)(4) (2), and (C6F5)Fe(PMe3)(4) (3) were obtained by selective activation of the C-F bonds. However, under similar reaction conditions, the reaction of Fe(PMe3)(4) with perfluoronaphthalene (C10F8) afforded a pi- coordinated Fe(0) complex, (eta(4)-1,2,3,4-C10F8)Fe(PMe3)(3) (4), and the expected C-F bond activation reaction was not observed. The expected iron hydride (C6F5)FeH(PMe3)(4) (6) could be obtained in a yield of 80% by the reaction of bromopentafluorobenzene with Fe(PMe3)(4) and subsequent reduction with NaBH4. The molecular structures of complexes 2, 4, and 6 were determined by single-crystal X-ray diffraction. Complexes 1-4 and 6 could be used as catalysts for the hydrosilylation of carbonyl compounds. Among them, complex 6 is the best catalyst. The selective reduction of carbonyl groups of alpha,beta-unsaturated aldehydes and ketones was also realized with 6 as catalyst.