Search

Studies the platinum-catalyzed reaction of 2-chloro-allyl acetate via nucleophilic substitution at the central carbon atom. Reaction with sodium ethyl acetoacetate; Regioselectivity of the nucleophilic attacks; Display of rapid syn-anti isomerization.

The article presents a study which analyzes the role of hydrogen (H)-bonding amides in activating the electrophilicity of the lactide that induces the ring opening polymerization (ROP). It uses L-lactide as the monomer in investigating new H-bonding architectures for the ROP of lactide. Results show that through activated amides, organocatalyzed ROP of L-lactide can be achieved. It demonstrates the efficiency of hydrogen-bonding amide 1e as an organocatalyst for the ROP of L-lactide.

Thermoresponsive properties of poly(7-methacryloyloxycoumarin) ( P1a ) and its derivatives as homopolymers containing a photoreactive coumarin unit were systematically investigated. P1a showed a lower critical solution temperature (LCST)-type phase separation in dichloromethane, chloroform, and 1,1,2-trichloroethane. The temperature producing a 50% transmittance ( T c ) of 0.1 wt% P1a in distilled chloroform was 26 °C, while the T c value decreased to 21 °C in deuterated chloroform i.e., the deuterium isotope effect. The T c values in chloroform were adjustable from 28 to 57 °C by the introduction of the ethyleneoxy spacer and the substitution of α-methyl group by hydrogen. While the polymers containing 4-substituted coumarins were soluble in chloroform and dichloromethane from 0 °C to their boiling points. In the distilled chloroform solution, the coumarin units in P1a underwent a [2 + 2] cycloaddition and the transmittance at 500 nm decreased from 98% to 29% at 25 °C by a 180-s photoirradiation (326 mJ/cm 2 , emission band at 365 nm). [ABSTRACT FROM AUTHOR]