Catalyst-controlled stereoselective cationic polymerization of vinyl ethers

The tacticity of vinyl polymers has a profound effect on their physical properties. Despite the well-developed stereoselective methods for the polymerization of propylene and other nonpolar α-olefins, stereoselective polymerization of polar vinyl monomers has proven more challenging. We have designed chiral counterions that systematically bias the reactivity and chain-end stereochemical environment during cationic polymerization. This approach overrides conventional chain-end stereochemical bias to achieve catalyst-controlled stereoselective polymerization. We demonstrate that this method is general to vinyl ether substrates, providing access to a range of isotactic poly(vinyl ether)s with high degrees of isotacticity. The obtained materials display the tensile properties of commercial polyolefins but adhere more strongly to polar substrates by an order of magnitude, indicating their promise for next-generation engineering applications.

Thermally induced cationic polymerization of isobutyl vinyl ether in toluene in the presence of solvate ionic liquid

Cationic polymerization of isobutyl vinyl ether at elevated temperatures of 60–100 °C, in which the propagating cations are stabilized with a solvate ionic liquid, is described.

Preparation of acetonides from soybean oil, methyl soyate, and fatty esters

This paper describes the preparation of a new type of branched vegetable oil and its methyl ester that involves the formation of acetonides. A facile and environmentally friendly synthesis has been found to produce acetonides that entails the use of ferric chloride as a catalyst and is conducted at room temperature. The products have been fully characterized with the help of model compounds, including elemental analysis, infrared (IR) spectroscopy, nuclear magnetic resonance (NMR), and gas chromatography-mass spectrometry (GC-MS).