Chemo- and regioselectivity in the reactions between highly electrophilic fluorine containing dicarbonyl compounds and amines. Improved synthesis of the corresponding imines/enamines

Chemo- and regioselectivity in the reactions between highly electrophilic fluorine containing dicarbonyl compounds (ethyl 4,4,4-trifluoroacetoacetate, 3,3,3-trifluoropyruvate and 1,1,1,5,5,5-hexafluoropentane-2,4-dione) and various benzylamines were systematically studied. The results obtained lead to the development of a generalized and practical method for large-scale synthesis of the corresponding imines/enamines, useful starting materials for preparation fluorinated amines and amino acid.     

Investigations of synthetic dyes. XLV. Styryls from N-arylquinaldine salts

Condensation of N-arylquinaldine salts with benzaldehyde and its o- and p-derivatives gives a series of styryl compounds. The absorption maxima of the hydroxystyryls are bathochromically shifted by 12–34 m, as compared with the unsubstituted analogs. Transformation of hydroxystyryl salts to the bases is linked with deepening of the color by 90–130 m.The other styryls were prepare similarly.     

Synthesis of organometallic compounds from trialkylaluminums and metal salts

Summary Reaction between trialkylaluminums and salts of antimony, bismuth, mercury, thallium, tin, and lead gives alkyl derivatives of these metals.     

Untersuchungen über Phenthiazinderivate. 10. Mitteilung

Zusammenfassung Es wurde ein allgemein anwendbarer Weg zur Herstellung von in -Stellung basisch substituierten 4,10-Trimethylenphenthiazinen durch Umsetzung der aus den -Hydroxyverbindungen erhaltenen -Bromverbindungen mit sekundären Aminen angegeben. Für das in der Literatur bekannte -Amino-4,10-Trimethylen-phenthiazin wurden neue Darstellungen beschrieben.     

The Role of Active Oxygen Transfer through the Gas Phase in Propylene Oxidation over a Bismuth–Molybdenum Catalyst

The transfer of atomic oxygen from the surface of bismuth oxide onto molybdenum oxide through the gas phase, including the case when ozone was fed to the catalyst bed, is experimentally studied. It is found that the transfer of atomic oxygen through the gas phase only leads to the formation of the products of complete oxidation of propylene under conditions of heterogeneous propylene oxidation on the mixture of molybdenum and bismuth oxides. No new sites are formed on the surface of molybdenum oxide.     

Synthesis and Reaction Chemistry of the Disodium Alkoxide of 2,6-Bis(trifluoromethyl)-2,6-dihydroxy-3,3,4,4,5,5-hexafluorooxane

The disodium alkoxide of 2,6-bis(trifluoromethyl)-2,6-dihydroxy-3,3,4,4,5,5-hexafluorooxane, C(7)F(12)O(3)Na(2), 1, was prepared by reaction of the corresponding diol with MeONa in MeOH. This cyclic alkoxide readily mimics the reaction chemistry of the lithium and sodium alkoxides of perfluoropinacol. The reaction of the alkoxide 1 with covalent dichlorides and metallocene dichlorides yields a series of novel bicyclic ring systems. The crystal structure of the trioxasilane, 3, formed from (CH(3))(2)SiCl(2) was determined to provide structural information about these ring systems. Crystal data: C(9)H(6)O(3)F(12)Si, fw = 418.21 u, orthorhombic space group, Pnma (No. 62), a = 15.822(3) ?, b = 12.163(3) ?, c = 7.373(2) ?, V = 1418.9(4) ?(3), and D(calc) = 1.96 g cm(-)(3) for Z = 4 (molecule possesses mirror symmetry). Least-squares refinement on 1075 observed reflections (I > 3sigma(I)) converged with R = 0.0357 and R(w) = 0.0478.     

Novel metal-organic ruthenium(II) diimin complexes for use as longwave excitable luminescent oxygen probes

New ruthenium(II) diimine complexes are presented which are useful as luminescent oxygen probes. Because their luminescence excitation maxima are between 535 and 570 nm, they can be photo-excited by green LEDs which are much brighter than the blue LEDs used so far for existing Ru diimines. The spectral and photophysical properties as well as the solubility properties of the new probes are investigated and discussed in terms of quenching, photostability, and lifetimes. The probes were incorporated into organic polymers by three different methods, to obtain oxygen-sensitive materials for use in optical oxygen sensing. The membranes were characterized with respect to oxygen sensitivity, luminescence intensity, response times, and stability. Notwithstanding the poor luminescence of the new ruthenium(II) probes, their stability, LED compatibility and efficient quenching by oxygen makes them an interesting alternative to existing luminescent oxygen probes.     

Computer-aided identification of powdered vegetable materials

The use and limitations of the microcomputer as an aid for the analyst in the identification of powdered vegetable materials is presented and suggestions are given for extending the applicability of the method and the programs described.     

Extremal problems for certain analytic (Nevanlinna) functions

We obtain sharp bounds on some basic functionals defined on the sets of all analytic functions having the representations \(f\left( z \right) \equiv \int\limits_{ - 1}^1 {\frac{{d\mu \left( t \right)}}{{z - t}}} \) and \(\varphi \left( z \right) \equiv \int\limits_{ - 1}^1 {\frac{{z\mu \left( t \right)}}{{1 - tz}}} \) ; respectively. Here μ is a probability measure.