Reactions of(4S,5R)-1-(3,4-Dimethyl-2-oxo-5-phenylimidazolidine)carbonyl-isocyanate (4) with appropriate Baylis-Hillman adducts 5 gave the corresponding acyl carbamates 6,7 as equimolar diastereomeric mixtures. These mixtures were treated with DABCO, to afford with moderate diastereoselection easily separable [2-(3",4"-dimethyl-2"-oxo-5"-phenylimidazolidine-1-carboxamido)(aryl)methyl]acrylates ...

A new asymmetric total synthesis of a phenanthroindolizidine alkaloid (S)-tylophorine is reported, which features a catalytic asymmetric allylation of aldehydes and an unexpected one-pot DMAP promoted isocyanate formation and Lewis acid catalyzed intramolecular cyclization reaction. In addition, White's direct C-H oxidation catalyst system converting monosubstituted olefins to linear allylic ac...

Polyurethanes and polyurethane-ureas were prepared by the reaction of diethylene glycol and polyethylene glycol with excess of aromatic and aliphatic diisocyanate to yield isocyanate terminated prepolymers which were subsequently reacted with diols and diamines. These polymers were characterized by IR, 1HNMR spectra, viscosity measurements and thermogravimetric analysis.

Fabrication and use of Cross Laminated Timber (CLT) using tropical woods is still limited at present. Therefore objective the present study aims to determine possibility CLT panels 3 5 layers, fabricated with Tectona grandis Gmelina arborea wood adhesive isocyanate polymer emulsion system catalyzed polymeric isocyanate. Delamination, water absorption, density, flexure test, compression glue-lin...

BACKGROUND Isocyanates constitute a group of highly reactive, low molecular weight chemicals used worldwide for polyurethane manufacturing. The occupational exposure to these compounds is a major cause of occupational asthma, thus it is very important to monitor their concentration in the workplace atmosphere. The aim of the study was to measure the concentration of 4,4'-methylenediphenyl diiso...