Search

ABSTRACT A number of chiral racemic and enanthiopure thiophosphorylated thioureas were synthesized by the reaction of 2-aminobutan-1-ol and 1-(a-aminobenzyl)-2-naphthol with O, O-diethyl thiophosphoryl isothiocyanate. It was found that such thioureas undergo the cyclization reaction under basic conditions with hydrogen sulfide elimination and the formation of thiophosphorylated oxasines. X-Ray single crystal diffraction revealed that the structure of thiourea is close to the prereaction state of the cyclization reaction. [ABSTRACT FROM AUTHOR]

A series of new mononuclear and heteronuclear complexes of carboxylate phosphonium betaines with biologically important metals (Zn(II), Cd(II), Hg(II) and Cu(II)) were obtained in aqueous media at ambient temperature. X-ray single crystal diffraction showed that carboxylate phosphonium betaines exhibit versatile complexation abilities, producing monomeric, dimeric and tetrameric homonuclear and mixed metal complexes. The binding mode was found to change in the series of Zn(II), Cd(II) and Hg(II) complexes with an increase of the cation radius. Water and chlorine atoms, bound to the metal, play an important role in crystal formation. In the case of α- and β-substituted phosphabetaines, the crystallization of various stereoisomers was observed including a rare case of co-crystallization of two diastereomers in one crystal. [ABSTRACT FROM AUTHOR]

Two different approaches have been employed to enhance the reactivity of 1-alkyl-1,2-diphospholes - the introduction of electron-withdrawing groups either at the phosphorus atoms or in the para-position of the arene ring. The alkylation of sodium 1,2-diphospha-3,4,5-triphenylcyclopentadienide with alkyl halides Hal-CH2-R (R = CN, COOEt, OMe, CH2OEt) results in corresponding 1-alkyl-3,4,5-triphenyl-1,2-diphospholes (alkyl = CH2CN (1a), CH2COOEt (1b), CH2OMe (1c), and (CH2)2OEt (1d)), which spontaneously undergo the intermolecular [4 + 2] cycloaddition reactions at room temperature to form the mixture of the cycloadducts, 2a-c, respectively. However the alkylation of sodium 1,2-diphospha-3,4,5-tri(p-fluorophenyl)cyclopentadienide with ethyl iodide leads to stable 1-ethyl-3,4,5-tris(p-fluorophenyl)-1,2-diphosphole (1e), which forms the [4 + 2] cycloadduct 2,3,4,4a,5,6-hexa(p-fluorophenyl)-1-ethyl-1,7,7a-triphospha-4,7-(ethylphosphinidene)indene (2e) only upon heating up to 60 °C. With further heating to 120 °C with N-phenylmaleimide, the cycloadducts 2a-c and 2e undergo the retro-Diels-Alder reaction and form only one product of the [4 + 2] cycloaddition reaction 3a-с, 3e with good yields up to 65%.

The mol-ecular structure of the trinuclear title compound, [Fe3(C10H8)3] {systematic name: tris-[μ-(η(5):η(5))-1,1'-bi-cyclo-penta-dien-yl]tri-iron(II)}, consists of three ferrocene subunits (each with an eclipsed conformation) that are condensed via C-C bonds of the fulvalene moieties into a cyclic trimer. The angles between the planes of the cyclo-penta-dienyl (Cp) rings within the three fulvalene moieties are 76.1 (3), 80.9 (3) and 81.7 (3)°. In the crystal, C-H⋯π inter-actions between neighbouring mol-ecules lead to the cohesion of the structure.