No abstract

No abstract

Ytterbium(III) complexes of benzenesulfonic acid, Yb(BSA) 3 , p-toluenesulfonic acid, Yb(Tos) 3 , and 2-naphthalenesulfonic acid, Yb(NSA) 3 , were prepared and tested as possible catalyst for the nitration of toluene. With a loading of 5-10 mol% of Yb(BSA) 3 and Yb(NSA) 3 , a quantitative conversion of toluene to nitrotoluene was achieved within 5 h, while Yb(Tos) 3 was slightly less active and 77% of nitrated products were obtained. The catalysts can be easily recovered after the reaction, and 1 H NMR spectroscopy of analogous diamagnetic lanthanide(III) catalysts showed that the recovered catalysts were identical to the freshly prepared ones. The ratio of ortho:meta:para products was in all reactions 52:6:42, which is consistent with a direct electrophilic attack by the nitronium ion, NO 2 + .

Lanthanide(III) complexes of p-toluenesulfonic acid (Ln(TOS) 3 ) were prepared, characterized, and examined as catalysts for the acetylation of various alcohols in acetic acid solution. Examination of a series of Ln(TOS) 3 catalysts in the acetylation of 2-phenylethanol revealed a clear correlation between the ionic radius of the lanthanide(III) ion and the yield of the reaction, with the heavier lanthanides being more effective. In the presence of 5 mol-% of Yb(TOS) 3 , a quantitative conversion of phenethyl alcohol to phenethyl acetate was achieved within 18 hours at 50°C. Faster reaction was obtained under reflux conditions, in which case acetylation

No abstract