Cationic copolymerization of β-propiolactone and 1,3-dioxolane

The reaction of terpinolene with tetrahydrogeraniol in the presence of boron trifluoride etherate gave an aromatic ether in addition to the corresponding aliphatic ether, along with p-cymene, p-cymen-8-ol, and the monoterpene hydrocarbons formed by double-bond migration. The aromatic ether was proved to form upon the treatment of the aliphatic ether with boron trifluoride etherate.

Oligomers containing peroxy groups have been synthesized on the basis of epoxides reacting with tert-butylhydroperoxide in the presence of boron trifluoride etherate. Dependence of reaction rates upon the quantity of catalyst, temperature and also nature of hydroperoxide has been investigated: A kinetic equation for the process has been formulated and also a kinetic scheme for the reaction taking into account the presence of boron trifluoride etherate is proposed. Structures of the synthesized peroxy oligomers have been confirmed by IR- and NMR-spectroscopy. The reaction initiating properties of the oligomers so synthesized were studied using as the example the styrene polymerization reaction.

Selective reduction of aldehydes with 8-oxyquinoline dihydroboronite in the presence of boron trifluoride etherate

In the presence of boron trifluoride etherate, some kinds of aliphatic ethers have been found to react with benzaldehyde dimethyl acetal yielding α,β-unsaturated carbonyl compounds with evolution of H2. In this reaction, dehydrogenation of the ether undergoes in cooperation with the acetal and BF3, which enables the ether molecule to behave as enol ether equivalent affording crossed aldol adduct via nucleophilic attack to oxycarbenium ion electrophile formed from the acetal.

Stereocontrol in hydride addition to ketone-derived chiral N-acylhydrazones

In the course of research into carbon-chain polymerization under the influence of the acid-type catalysts, aluminum chloride, boron fluoride, stannic chloride, and others, a series of investigations have established the fundamental mechanisms of these chain processes, indicating that they have an ionic character. On the basis of this research, it was suggested that the active center in carbon-chain polymerization is a compound with a tervalent positive carbon atom at the end. The kinetics of catalytic copolymerization had not been studied until the present. There has been only a little work published in connection with determining the composition of copolymers and calculating the copolymerization constants for the systems in question. We initiated some research into the dependence of the speed of catalytic copolymerization on the composition of the original mixture, in conjunction with a determination of the speeds of separate polymerization of the monomers involved, since a comparison of data on the kinetics of copolymerization with that of separate polymerization gives a more complete representation of the mechanism of the process. A study was made of the speed of copolymerization of the systems : isoprene-butadiene and styrene-butadiene, and also of the kinetics of separate polymerization of these monomers. Polymerization was carried out in ethyl chloride with stannic chloride as the catalyst, at 0° C, by the dilatometric method.

N‐Aryl‐2‐cyanodiazoacetamides produce polycyclic difluoroboron 2‐oxoindoline‐3‐carboxamide complexes (up to pentacyclic conjugative and fused systems) directly and expeditiously in the presence of boron trifluoride etherate. The boron trifluoride serves as both a catalyst and reactant in the tandem reaction. The tandem reaction includes the carbene aromatic CH insertion, hydrolysis of the cyano group into an amide group, and boronation of the two amide carbonyl groups. The synthetic method features the advantages of wide substrate scope and excellent chemoselectivity.magnified image

Application of response surface methodology for optimizing transesterification of Moringa oleifera oil: Biodiesel production

Studies on miscibility in polycarbonate/poly(styrene-co-acrylonitrile) blends by ellipsometry

Background: Bromide is found naturally in groundwater and surface water. The rapid growth of industrial activities, drainage of surface runoff, and use of methyl bromide in pesticides has increased bromide discharge to the environment. Disinfection of water-containing bromide causes the creation of additional products of organo-halogenated that are considered cancer-causing agents. In this study, the effect and optimization of factors in removal of this ion was evaluated by using the nano-photocatalytic UV/ZnO process. Methods: This analytical study was conducted in a batch system by the phenol-red method. The test design was performed through the analysis model of multi-factor variance with 99 subjects, while the main, interactive, and reciprocal effects of variables, such as reaction time, catalyst concentration, bromide concentration, and pH at different levels of each factor, were analysed by using SPSS version 16. Results: The main, interactive, and reciprocal effects of factors were significant in three different levels with P < 0.001, and the optimal level of the factors reaction time, catalyst concentration, bromide concentration, and pH were 120 minutes, 0.5, 0.1, and 7 mg/L, respectively, by using the Schaffer test. The highest removal efficiency of 95% was obtained at least 91.56 and a maximum of 94.76% was obtained under optimal conditions of all factors. Conclusion: The results show that by optimization of factors, this process can be effectively used to remove bromide from aquatic environments. Keywords: Bromides, Water, Reaction Time, UV/Zn

The bicyclic 1‐oxoalkyl ketones (I), (V), or (VIII) react with ethylene glycol (II) in the presence of boron trifluoride etherate to form mixtures of the spirocyclic hydroxyethyl esters (III), (VI), or (IX) and the tricyclic β,γ‐unsaturated ketones (IV), (VII), or (X).

The N-(4-substituted phenyl)-N'-cyclohexylideneacetylthioureas IIa - IIf were readily prepared by the reaction of cyclohexylideneacetyl isothiocyanate I with 4-substituted anilines. They were cyclized to the 2-(4-substituted phenylimino)-4-oxo-1,3-thiazaspiro[5.5]undecanes IIIa - IIIe in the presence of boron trifluoride etherate and to the 1-(4-substituted phenyl)-4-oxo-2-thioxo-1,3-diazaspiro[5.5]undecanes IVa, IVc - IVf in alkaline medium.

Total Synthesis of (−)-trans-kumausyne

A new general synthetic route to bridged carboxylic ortho esters

Tellurium-based organic synthesis: A novel one-pot formation of 2-oxazolines from alkenes induced by amidotellurinylation