| Abstract
| - The syntheses and reactivity of seven different ruthenium-based metathesis catalysts are described.Ru(CF3COO)2(PCy3)(CH-2-(2-PrO)C6H4) (1), Ru(CF3COO)2(1,3-dimesityldihydroimidazolin-2-ylidene)(CH-2-(2-PrO)C6H4) (2), and Ru(CF3COO)2(PCy3)(1,3-dimesityldihydroimidazolin-2-ylidene)(CHC6H5) (3) were prepared via chlorine exchange by reacting RuCl2(PCy3)2(CH-2-(2-PrO)C6H4), RuCl2(1,3-dimesityldihydroimidazolin-2-ylidene)(CH-2-(2-PrO)C6H4), and RuCl2(PCy3)(1,3-dimesityldihydroimidazolin-2-ylidene)(CHC6H5), respectively, with silver trifluoroacetate (Cy = cyclohexyl). Inanalogy, Ru(CF3CF2COO)2(1,3-dimesityldihydroimidazolin-2-ylidene)(CH-2-(2-PrO)C6H4) (4) and Ru(CF3CF2CF2COO)2(1,3-dimesityldihydroimidazolin-2-ylidene)(CH-2-(2-PrO)C6H4) (5) were preparedfrom RuCl2(1,3-dimesityldihydroimidazolin-2-ylidene)(CH-2-(2-PrO)C6H4) via reaction with CF3CF2COOAg and CF3CF2CF2COOAg, respectively. Ru(C6F5COO)2(1,3-dimesityldihydroimidazolin-2-ylidene)(CH-2-(2-PrO)C6H4) (6) and Ru(C6F5O)2(1,3-dimesityldihydroimidazolin-2-ylidene)(CH-2-(2-PrO)C6H4) (7) were prepared from RuCl2(1,3-dimesityldihydroimidazolin-2-ylidene)(CH-2-(2-PrO)C6H4)via reaction with C6F5COOTl and C6F5OTl, respectively. Supported catalysts Ru(PS-DVB-CH2OOCCF2CF2CF2COO)(CF3COO)(PCy3)(1,3-dimesityldihydroimidazolin-2-ylidene)(CHC6H5) (8), Ru(PS-DVB-CH2OOCCF2CF2CF2COO)(CF3COO)(PCy3)(CH-2-(2-PrO)C6H4) (9), and Ru(PS-DVB-CH2OOCCF2CF2CF2COO)(CF3COO)(1,3-dimesityldihydroimidazolin-2-ylidene)(CH-2-(2-PrO)C6H4) (10) weresynthesized by reaction of RuCl2(PCy3)(1,3-dimesityldihydroimidazolin-2-ylidene)(CHC6H5), RuCl2(PCy3)(CH-2-(2-PrO)C6H4), and RuCl2(1,3-dimesityldihydroimidazolin-2-ylidene)(CH-2-(2-PrO)C6H4),respectively, with a perfluoroglutaric acid-derivatized poly(styrene-co-divinylbenzene) (PS-DVB) support(silver form). Halogen exchange in PCy3-containing systems had to be carried out in dichloromethanein order to suppress precipitation of AgCl·PCy3. The reactivity of all new catalysts in ring-closingmetathesis (RCM) of hindered electron-rich and -poor substrates, respectively, at elevated temperature(45 °C) was compared with that of existing systems. Diethyl diallylmalonate (DEDAM, 11), diethylallyl(2-methylallyl)malonate (12), N,N-diallyl-p-toluenesulfonamide (13), N-benzyl-N-but-1-en-4-ylbut-2-enecarboxylic amide (14), and N-allyl-N-(1-carboxymethyl)but-3-en-1-yl-p-toluenesulfonamide (15)were used as educts. Supported catalysts were prepared with high loadings (2.4, 22.1, and 160 mg ofcatalyst/g PS-DVB for 8, 9, and 10, respectively). Catalyst 8 showed higher and catalysts 9 and 10sowed significantly reduced activities in RCM compared to their homogeneous analogues. Thus, with8, turnover numbers (TONs) up to 4200 were realized in stirred-batch (carousel) RCM experiments.To elucidate the nature of the bound species, catalysts 8−10 were subjected to 13C- and 31P-MAS NMRspectroscopy. These investigations provided evidence for the proposed structures. Leaching of rutheniuminto the reaction mixture was low, resulting in ruthenium contents <85 ppb (ng/g) in the final RCM-derived products.
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