New selectivities from old catalysts. Occlusion of Grubbs’ catalysts in PDMS to change their reactions

Pd-Boron-Catalyzed One Carbon Isomerization of Olefins: Water Assisted Process at Room Temperature

“…(E)-2-Methoxy-4-(prop-1-en-1-yl)phenol (2d). 21 Prepared as described in the general experimental procedure. colorless liquid; yield: 50% (41 mg); R f (5% EtOAc/hexane): 0.1; IR (Neat, cm −1 ): 1513, 1413, 1263, 1232, 1191, 1027, 963, 856; 1 H NMR (400 MHz, CDCl 3 ): δ 6.89 (s, 1H), 6.87−6.78 (m, 2H), 6.34 (d, J = 15.6 Hz, 1H), 6.15−6.06 (m, 1H), 3.89 (s, 3H), 3.87 (s, 3H), 1.87 (d, J = 6.4 Hz, 3H); 13 C{ 1 H} NMR (100 MHz, CDCl 3 ): δ 148.9, 148.1, 131.1, 130.5, 123.7, 118.6, 111.1, 108.3, 55.9, 55.7, 18.3.…”

A High‐Performance Renewable Thermosetting Resin Derived from Eugenol

“…In cases in which alkenes are available for reaction, olefin metathesis can be a powerful technique to generate new CC bonds selectively. The self‐metathesis of eugenol with first‐ and second‐generation Grubbs catalysts has been described,8, 9 as have a number of cross‐metathesis reactions 10. 11 As an extension of this chemistry, a variety of bifunctional monomers that contain eugenol moieties have been prepared with various linkers that include butyl, decyl, carbonate, and glycol groups.…”

Transformations of bio‐sourced 4‐hydroxyphenylpropanoids based on olefin metathesis

“…The self‐metathesis of ( 1 ) was also successfully achieved in the presence 1 mol% of the second generation ruthenium complex Ru2 in dichloromethane as solvent ( c= 0.4 M). After 5 h at 25 °C, ( 6 ) was isolated in 63 % yield as a mixture of E and Z isomers . It was also shown that when this catalyst Ru2 was occluded in polydimethylsiloxane and used in a protic MeOH/H 2 O mixture (90 : 10 vol %) as solvent, the metathesis catalyst properties were lost and new properties of double bond isomerization appeared.…”

“…After 5 h at 25°C, (6) was isolated in 63 % yield as a mixture of E and Z isomers. [23] It was also shown that when this catalyst Ru2 was occluded in polydimethylsiloxane and used in a protic MeOH/H 2 O mixture (90 : 10 vol %) as solvent, the metathesis catalyst properties were lost and new properties of double bond isomerization appeared. Thus, the reaction of eugenol in this mixed solvent (c = 0.9 M) at 100°C for 20 h in the presence of 1 mol% of occluded Ru2 catalyst did not provide the self-metathesis product (6) but only isoeugenol, the corresponding β-methylstyrene derivative in 82 % yield.…”

“…Thus, the reaction of eugenol in this mixed solvent (c = 0.9 M) at 100°C for 20 h in the presence of 1 mol% of occluded Ru2 catalyst did not provide the self-metathesis product (6) but only isoeugenol, the corresponding β-methylstyrene derivative in 82 % yield. [23] With a catalyst loading of 0.5 mol%, the catalyst Ru3 ( Figure 2) was found to be moderately active at room temperature for the self-metathesis of (1) leading to 48 % conversion in toluene (c = 0.45 M) within 1 h but no information about yield and stereoselectivity was given. This conversion could be Dr. C. Bruneau graduated in chemistry from the Institut National Supérieur de Chimie Industrielle de Rouen (France, 1974) and got his PhD at the University of Rennes (1979).…”