Enantioenriched secondary and tertiary alkyl pinacolboronic esters undergo enantiospecific deborylative alkynylation through a Zweifel-type alkenylation followed by a 1,2-elimination reaction. The process involves use of α-lithio vinyl bromide or vinyl carbamate species, for which application to Zweifel-type reactions has not previously been explored. The resulting functionalized 1,1-disubstitu...

The results of our studies on the extraction and disposition of three plasticizing substances which are extracted from poly(vinyl chloride) medical devices will be reported. The plasticizers are di-2-ethylhexyl phthalate (DEHP), di-2-ethylhexyl adipate (DEHA), and butylglycolyl butyl phthalate (BGBP). DEHP extraction will be described in greater detail, and the two other plasticizers, DEHA and ...

A series of thiol-Michael and radical thiol-ene network polymers were successfully prepared from ester-free as well as ester-containing monomer formulations. Polymerization reaction rates, dynamic mechanical analysis, and solvent resistance experiments were performed and compared between compositions with varied ester loading. The incorporation of ester-free alkyl thiol, vinyl sulfone and allyl...

Background: Lipase is an enzyme with immense application potential. Ester synthesis by lipase catalysis in organic media is an area of key industrial relevance. Enzymatic preparations with traits that cater to the needs of this function are hence being intensely researched. Objective: The objectives of the study were to immobilize the lipase from Bacillus sp. PS35 by cross-linking and adsorpti...

in this study, the effect of hydrocarbon and rosin ester resins combination on the physical and mechanical properties of thermoplastic road markings were evaluated. at first, two basic thermoplastic road marking formulations based on hydrocarbon and rosin ester resins were prepared. several samples of the blends of two basic formulations for thermoplastic road marking were characterized and com...

The hydrosilylation reaction is a dominant curing method for the light-emitting diode (LED) silicone encapsulant, which requires characteristics of high transparency, high refractive index, and thermal stability against the LED junction temperature. In this research, we synthesized a hydrogen containing oligosiloxane resin through non-hydrolytic sol–gel condensation. Methyldiethoxysilane (MDES)...

background: lipase is an enzyme with immense application potential. ester synthesis by lipase catalysis in organic media is an area of key industrial relevance. enzymatic preparations with traits that cater to the needs of this function are hence being intensely researched. objective: the objectives of the study were to immobilize the lipase from bacillus sp. ps35 by cross-linking and adsorptio...

The aim of this work was to investigate the possibility of employing semi-covalent molecularly imprinted polymers (MIPs) as a controlled release device for ibuprofen and naproxen in biological fluids, especially gastrointestinal ones, compared to non imprinted polymers (NIPs). The carboxyl groups of ibuprofen and naproxen were converted to vinyl ester group by reacting ibuprofen and vinyl aceta...

The synthesis of the marine natural product 1,6Z,9Z,12Z,15Z-octadecapentaen-3-one (1) has been achieved by two different routes starting from the ethyl esters of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), respectively. Using EPA ethyl ester as starting material the polyunsaturated vinyl ketone lipid 1 was obtained in 17% overall yield.

Purpose: To compare in vitro fracture resistance of endodontically treated premolars restored with bonded amalgam or resin composite. Materials and Methods: Fifty intact and caries-free premolars that had been extracted for orthodontic treatment were selected. All teeth were subjected to endodontic procedures and MOD cavity preparation. They were then randomly divided into the five following gr...