Carboranyl phosphites: the electronic effect in the Suzuki- Miyaura reaction

Isomeric carborane-containing phosphite ligands possessing different electronic properties have been synthesized. Their use in the Pd-catalyzed Suzuki-Miyaura reaction involving activated aryl bromides showed that phosphite with 9-o-carborane substituent has proved more efficient, with carboranyl phosphite having 1-m- carborane fragment being more efficient in the reactions with nonactivated aryl bromides.     

Synthesis and structure of copper(II) complex with comenic acid

Russian Journal of General Chemistry -     

Asymmetric hydrogenation with the use of chiral carborane amidophosphite derivatives in supercritical carbon dioxide and CH2Cl2

New chiral carborane-containing amidophosphites containing the BINOL fragment (BINOL stands for 2,2′-dihydroxy-1,1′-binaphthyl) have been synthesized. The study of efficiency of these compounds as ligands in the Rh-catalyzed asymmetric hydrogenation of enamides in supercritical carbon dioxide (scCO₂) and CH₂Cl₂ showed that enantioselectivity of the process is considerably higher in scCO₂.     

Allowance for the effect of hydrostatic pressure in calculating the deformation of polymer structural elements

Simple equations of state of hereditary type are introduced and the results of analyzing certain experiments are presented. A solution of the problem of determining the stresses and strains in the case where the average stress does not depend on the coordinates is given for the equations of state in question.Central Scientific-Research Institute of Chemistry and Mechanics, Moscow. Translated from Mekhanika Polimerov, No. 1, pp. 50–57, January–February, 1973.     

On the properties of the anions derived from α-deprotonation of α-(o-carboran-1-yl)- and α-ferrocenyl-1-alkylbenzotriazoles

The synthesis of 1-[(2-R-o-carboran-1-yl)methyl]benzotriazoles (R = Me, Ph) is described. α-Deprotonation of these compounds followed by reactions of the generated carbanions with MeI give the corresponding α-methylated products. Even at room temperature, they exist in solution as an equilibrium mixture of two conformers due to steric crowding around the C^α atom. In contrast, the anions generated by deprotonation of α-ferrocenyl derivatives of 1-methyl- and 1-ethylbenzotriazoles are ambident and are attacked by electrophiles at both the C^α and N(3) atoms.     

Allyl substitution in a supercritical carbon dioxide medium catalyzed by complexes of palladium with phosphite-type ligands

Allyl amination and alkylation catalyzed by a palladium complex-phosphite-type-ligand catalyst in a supercritical carbon dioxide (SC-CO₂) medium is studied. It is demonstrated that that the Pd-containing catalysts dissolved in SC-CO₂ provide a high regioselectivity of the reaction and, thus, offer a convenient method for synthesizing allylamines.     

Curves on the Oeljeklaus-Toma manifolds

The Oeljeklaus-Toma manifolds are complex non-Kähler manifolds constructed by Oeljeklaus and Toma from certain number fields and generalizing the Inoue surfaces S _m . We prove that the Oeljeklaus-Toma manifolds contain no compact complex curves.     

An IR study of organosolvent lignin

The functional composition of lignin recovered from spruce wood and treated with alkali in aqueous and aqueous-ethanol medium and that of lignins recovered from alkaline cooking solutions in the presence of ethanol were studied by IR spectroscopy. The influence of ethanol on the content of the main functional groups in lignin was examinated.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 9, 2004, pp. 1547–1550.Original Russian Text Copyright © 2004 by Skrebets, Bogolitsyn, Kosyakov, Verbitskaya.     

Asymmetric hydrogenation of (<Emphasis Type="Italic">E</Emphasis>)-dimethyl-2-acetamido-2-phenylvinylphosphonate in supercritical carbon dioxide in the presence of metal complex catalysts with phosphite-type ligands

Asymmetric hydrogenation of (E)-dimethyl-2-acetamido-2-phenylvinylphosphonate was performed in CH₂Cl₂ and supercritical carbon dioxide with the participation of Rh and Ir complexes with chiral phosphite-type ligands. Iridium catalysts dissolved in supercritical CO₂ allow high enantioselectivity (up to 98.5% ee) and conversion to be obtained. Rhodium catalysts yield exclusively racemic reaction products.