Determination of the Degree of Crystallinity of Poly(2-methyl-2-oxazoline)

A new method for purification of 2-methyl-2-oxazoline using citric acid was developed and living cationic ring-opening polymerization of 2-methyl-2-oxazoline was carried out. Polymerization was conducted in acetonitrile using benzyl chloride—boron trifluoride etherate initiating system. According to DSC data, the temperature range of melting of the crystalline phase of the resulting polymer was 95–180 °C. According to small-angle X-ray scattering and wide-angle X-ray diffraction data, the degree of crystallinity of the polymer was 12%. Upon cooling of the polymer melt, the polymer became amorphous. Using thermogravimetric analysis, it was found that the thermal destruction of poly(2-methyl-2-oxazoline) started above 209 °C.

Rational Design 2-Hydroxypropylphosphonium Salts as Cancer Cell Mitochondria-Targeted Vectors: Synthesis, Structure, and Biological Properties

It has been shown for a wide range of epoxy compounds that their interaction with triphenylphosphonium triflate occurs with a high chemoselectivity and leads to the formation of (2-hydroxypropyl)triphenylphosphonium triflates 3 substituted in the 3-position with an alkoxy, alkylcarboxyl group, or halogen, which were isolated in a high yield. Using the methodology for the disclosure of epichlorohydrin with alcohols in the presence of boron trifluoride etherate, followed by the substitution of iodine for chlorine and treatment with triphenylphosphine, 2-hydroxypropyltriphenylphosphonium iodides 4 were also obtained. The molecular and supramolecular structure of the obtained phosphonium salts was established, and their high antitumor activity was revealed in relation to duodenal adenocarcinoma. The formation of liposomal systems based on phosphonium salt 3 and L-α-phosphatidylcholine (PC) was employed for improving the bioavailability and reducing the toxicity. They were produced by the thin film rehydration method and exhibited cytotoxic properties. This rational design of phosphonium salts 3 and 4 has promising potential of new vectors for targeted delivery into mitochondria of tumor cells.

La-Faujasite zeolite activated with boron trifluoride: synthesis and application as solid acid catalyst for isobutane–isobutene alkylation

The sodium form of Faujasite Y (Na-FAU) zeolite has been synthesized by the hydrothermal method, and it has been exchanged with ammonium sulphate and later with lanthanum (III) chloride solutions to obtain the La-FAU catalyst. The three zeolites Na-FAU, NH4+-FAU and La-FAU have been characterized by microcrystalline X-ray diffraction, X-ray fluorescence, surface area, pore volume and Brönsted acid sites. The La-FAU catalyst has been successfully activated with boron trifluoride etherate, and it has been tested in the alkylation reaction of isobutane with isobutene up to 112 h of time on stream, since the raw La-FAU catalyst showed a rapid deactivation.

Oxidative C-H/C-H Coupling of Dipyrromethanes with Azines by TiO2-Based Photocatalytic System. Synthesis of New BODIPY Dyes and Their Photophysical and Electrochemical Properties

Oxidative C-H/C-H coupling reactions of dipyrromethanes with azines in the presence of a heterophase oxidative photocatalytic system (O2/TiO2/visible light irradiation) were carried out. As a result of cyclization of obtained compounds with boron trifluoride etherate, new hetaryl-containing derivatives of 4,4-difluoro-4-boron-3a,4a-diaza-s-indacene were synthesized. For the obtained compounds, absorption and luminescence spectra, quantum yields of luminescence as well as cyclic volt-amperograms were measured.

BF3•OEt2 Catalysed chemoselective C=C bond cleavage of α,β-enones: An unexpected synthesis of 3-alkylated oxindoles and spiroindolooxiranes

A BF3•OEt2 catalyzed highly chemoselective formal C=C double bond cleavage reaction of α,β-enones with diazoamides for the synthesis of 3-alkylated oxindoles is developed. Boron trifluoride etherate is found to be...

An Efficient One-Pot Protocol for Direct Access to Diarylmethyl Thioglycosides with para-Quinone Methides via S-Glycosyl Isothiouronium Salts

An efficient one-pot protocol has been developed for the direct preparation of diarylmethyl thioglycosides starting from per-O-acetylated sugars via glycosyl isothiouronium salts. The one-pot reaction conditions involve rapid conversion of the per-O-acetylated sugar with thiourea in the presence of boron trifluoride etherate as catalyst to give the corresponding glycosyl isothiouronium salt, which is subsequently treated with a para-quinone methide in the presence of a base to give the a diarylmethyl thioglycoside in excellent yield.

Synthesis and Biological Evaluation of Heterocyclic Substituted Bis(indolyl)methanes

Background: Bis(indolyl)methane derivatives are widely found in nature with a broad range of biological and pharmacological activities. The development of techniques for the synthesis and functionalization of bis(indolyl)methanes have attracted more and more attention in recent years. Objective: To study the synthesis and biological activity of heterocyclic substituted bis(indolyl)methanes. Materials and Methods: A series of heterocyclic substituted bis(indolyl)methanes (3a-3p) have been prepared by condensation reaction of indole and heterocyclic aldehydes catalyzed by boron trifluoride etherate with high yields. Preliminary in vitro anti-inflammatory in lipopolysaccharide (LPS)-stimulated RAW-264.7 macrophages and cytotoxic activity against human tumor cell lines (A549, Hela and SGC7901) by MTT assay were tested. Results: The result indicated that heterocyclic substituted bis(indolyl)methanes showed good antiinflammatory and selective cytotoxic activity. Especially, compounds 3o, 3p and 3q displayed similar inhibitory effect on the generation of NO to positive control dexamethasone, and compound 3q displayed similar selective cytotoxic activity to 5-FU. Conclusion: Heterocyclic substituted bis(indolyl)methanes may be used as potential anti-inflammatory and anticancer leads.

Development of New Polymers from Thevetia peruviana Oil

Three novel bio-polymers were synthesized by cationic polymerization of Thevetia peruviana seed oil with styrene and divinylbenzene using modified boron trifluoride etherate as initiator. The cured thermosets ranging from soft to hard, were found to contain between 74.8 to 85.5 % cross linked materials with crosslink densities ranging from 1.33 x 103 to 1.84 x 103 mol/m3. The ultimate tensile strength of the materials varied from 0.52 to 0.55 Mpa, the young moduli is between 38.4 to 53.9 Mpa, the elongation at break varied from 55 to 64 %, the density of the polymers ranged between 0.850 to 0.866 gcm-3, the impact strength is between 2.31 to 2.81 J, while hardness ranged between 3.40 to 3.90 BHN. Overall, the newly synthesized materials from Thevetia peruviana oil have many potentials as new polymeric materials.

SYNTHESIS AND PROPERTIES OF BORON-CONTAINING OLIGOMERS BASED ON HYDROQUINONE AND BORIC ACID

By polyesterification of boric acid with hydroquinone in o-xylene with azeotropic distillation of water, polyesters of hydroquinone and boric acid are obtained. By adding equimolar amounts of phenol to the reaction between boric acid and hydroquinone, a mixed polyester of hydroquinone, phenol and boric acid is obtained. From the ratio of the integral intensity of phenol protons to hydroquinone protons, it was found that the addition of phenol to the hydroquinone polydiester and boric acid occurs by 80%. The synthesized polyesters reacted with formaldehyde using o-xylene as a solvent and a boron trifluoride etherate catalyst. By the method of end groups it was determined that all the compounds obtained have a small molecular weight and belong to the class of oligomers. The structure of the synthesized oligomers was confirmed by elemental analysis, IR and NMR (1H, 13C) spectroscopy. All compounds obtained have a good adhesion to glass, wood and metal. The thermal destruction of samples in a flow of nitrogen at 900 °C was studied, the residual mass for polyesters is from 49 to 53%, for polymethylene ester - from 18.5 to 31%. The residual mass during thermo-oxidative degradation in an air flow at 600 ° C for polyesters is from 62 to 65%, for polymethylene ester from 37 to 44%. The reaction of the modification of synthesized oligomers with a sulfur curing system and epoxy resin was studied. The maximum content of insoluble gel fraction when cured by sulfuric system at a temperature of 220 °C reaches 94% for polymethylene diester hydroquinone and boric acid, the minimum is 68% for the polytriester of hydroquinone and boric acid. The maximum content of insoluble gel fraction when cured with epoxy resin at a temperature of 150 °C for polyesters is in the range 52 - 66 %, for polymethylene ester 50 - 61%.