Synthesis and characterization of planar-chiral cyclopentadienylruthenium–vinylidene complexes
作者:Yoshiki Ajioka、Yuji Matsushima、Kiyotaka Onitsuka、Hiroshi Yamazaki、Shigetoshi Takahashi
DOI:10.1016/s0022-328x(00)00736-1
日期:2001.1
Enantiopure planar-chiral cyclopentadienylruthenium-vinylidene complexes, (S-Cl)- and (R-Cl)-[(eta (5)-C5H2-1 -COR'-2-Me-4-R-2)RU(PPh3)(2)(=C=CHR3)1[PF6] (4: R-1 = O-(l)- and O-(d)-menthyl; 8: R-1 = NH'Bu. R-2 = Me, Ph; R-3 = Ph, H), were synthesized starting from [(eta (5)-C5H2-1-COR1 -2-Me-4-R-2)Ru(eta (6)-C6H6)][PF6], and characterized by optical and spectra methods including H-1, C-13,and P-31-NMR, and CD spectra. The reaction rate of [(eta (5)-C5H2-1-CO2Et-2,4-Me,)Ru(PPh3)(2)(MeCN)(3)[PF6] with phenylacetylenes leading to vinylidene complexes increases in the order: HCCC6H4NO2 < HCCC6H5 < HCCC6H5OMe. Analysis by cyclic voltammetry showed that trisubstituted cyclopentadienyl ligands C5H2-1-CO2Et-2-Me-4-R-2 (R-2 = Me, Ph, 'Bu, Naph etc.) act as a weak electron-donor compared with non-substituted cyclopentadienyl one in ruthenium-phenylacetylide complexes. (C) 2001 Elsevier Science B.V. All rights reserved.