Reactions of sterically hindered phenols with P2S5

The direction of the reaction of 2,6-disubstituted phenols with P₂S₅ leading to bis(hydroxyaryl)dithiophosphinic acids orO,O-bis(aryl) dithiophosphates is determined by the degree of shielding of the OH group. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1442–1444, July, 1998.     

Novel mesoporous mixed Nb-M (M = V, Mo, and Sb) oxides for oxidative dehydrogenation of propane

Novel thermally stable mesoporous mixed metal Nb-M (M = V, Mo and Sb) oxides were synthesized in the presence of a nonionic Pluronic P123 surfactant. These oxides displayed promising pore structures and chemical compositions for selective oxidative functionalization of propane: high surface areas (up to 200 m2/g), large pore sizes (5-14 nm), and high pore volumes (up to 0.46 cm3/g). The oxidative dehydrogenation of propane to propylene over mesoporous mixed metal Nb-M oxides employed as a probe reaction suggested that the M component was dispersed as the molecular surface species and also formed a solid solution with NbOx in the inorganic walls of these mesoporous mixed metal oxides.     

Asymmetric Diels-Alder reaction between acrylates and cyclopentadiene in the presence of chiral catalysts

Asymmetric Diels-Alder reaction between cyclopentadiene and alkyl and cycloalkyl acrylates in the presence of new chiral catalysts, BBr₃·MentOEt, AlCl₂OMent, BBr₂OMent, and BBr(OMent)₂, was studied. Optically active bicyclo[2.2.1]hept-2-ene-5-carboxylates were synthesized. The influence of the reaction conditions on the total and optical yields and on the stereoselectivity of the adducts synthesized was examined.     

Synthesis and Functionalization of 3-Ethylquinoxalin-2(1<Emphasis Type="Italic">H</Emphasis>)-one

A new and effective procedure was developed for the synthesis of 3-ethylquinoxalin-2(1H)-one from o-phenylenediamine and ethyl 2-oxobutanoate. The latter was prepared by the Grignard reaction of diethyl oxalate with ethylmagnesium bromide or iodide. The ethyl group in 3-ethylquinoxalin-2(1H)-one can readily be converted into various functional groups: α-bromoethyl, α-thiocyanato, α-azidoethyl, α-phenylaminoethyl, acetyl, and bromoacetyl. The reaction of 3-(bromoacetyl)quinoxalin-2(1H)-one with thiourea and hydrazine-1,2-dicarbothioamide gives the corresponding 3-(2-amino-4-thiazolyl) derivatives.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 4, 2005, pp. 609–616.Original Russian Text Copyright © 2005 by Mamedov, Kalinin, Gubaidullin, Isaikina, Litvinov.     

Evaluation of the Boys Function using Analytical Relations

The analytical relations for Boys function F _m (x) are presented. These relations are useful in the fast and more accurate calculations of multicenter molecular integrals over Gaussian type orbitals (GTOs). The formulas obtained are numerically stable for all values of m and x.     

Calculation of molecular electric and magnetic multipole moment integrals of integer and noninteger n Slater orbitals using overlap integrals

Closed formulas are established for the magnetic multipole moment integrals of integer and noninteger n Slater‐type orbitals (ISTOs and NISTOs) in terms of electric multipole moment integrals for which the analytic expressions through the overlap integrals with ISTOs and NISTOs are derived. The overlap integrals are evaluated by the use of auxiliary functions. Using the derived expressions the multipole moment integrals, and therefore the electric and magnetic properties of molecules, can be evaluated most efficiently and accurately. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003     

Production of alkane and cyclohexane derivatives with two heterocyclic substituents of the furan,pyrrole, and thiophene series

Heating 1,2,11,12-tetrachloro-2,11-bis(R-4,9-dodecanediones) and 1,4-bis(3-R-3,4-dichlorobutanoyl)cyclohexanes gave, respectively, 1,4-difuryl derivatives of butane and cyclohexane, while treatment of them with primary amines or phosphorus pentasulfide in DMF was used to synthesize dipyrryl and dithienyl compounds. 1-R-3-R¹-3,4-Dichlorobutanones react with ethylenediamine in aqueous alkali solutions to give 1,2-dipyrryl or monopyrryl derivatives of ethane.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1185–1189, September, 1991.     

Mechanism of oxidative dehydrodimerization of propylene over Bi?Sn oxide catalysts

The kinetics of oxidative dehydrodimerization of propylene has been studied and interpreted in terms of the Langmuir-Hinshelwood scheme. Diallyl is shown to be formed by interaction between the gaseous and adsorbed forms of olefin.

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