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Herein we report a transition-metal- and acid-free protocol for the reductive amination of carbonyl compounds with DMF using a substoichiometric amount of NaH2PO2·H2O. The general trends and limitations of the method were explored.

On the basis of the 1,2,3,4-tetrahydrofluorenyl ligand, a simple approach was developed to new effective rhodium catalysts for the construction of C-C and C-N bonds. The halide compounds [(η5 -tetrahydrofluorenyl)RhX2 ]2 (2 a: X=Br; 2 b: X=I) were synthesized by treatment of the bis(ethylene) derivative (η5 -tetrahydrofluorenyl)Rh(C2 H4 )2 (1 a) with halogens. An analogous reaction of the cyclooctadiene complex (η5 -tetrahydrofluorenyl)Rh(cod) (1 b) with I2 is complicated by the side formation of [(cod)RhI]2 . The reaction of 2 b with 2,2'-bipyridyl leads to cation [(η5 -tetrahydrofluorenyl)Rh(2,2'-bipyridyl)I]+ (3). The halide abstraction from 2 a,b with thallium or silver salts allowed us to prepare sandwich compounds with incoming cyclopentadienyl, dicarbollide and mesityleneligands [(η5 -tetrahydrofluorenyl)RhCp]+ (4), (η5 -tetrahydrofluorenyl)Rh(η-7,8-C2 B9 H11 ) (5), and [(η5 -tetrahydrofluorenyl)Rh(η-mesitylene)]2+ (6). The structures of 1 b, 2 b ⋅ 2I2 , 3PF6 , 4TlI4 , 5, and [(cod)RhI]2 were determined by X-ray diffraction. Compounds 2 a,b efficiently catalyze the oxidative coupling of benzoic acids with alkynes to selectively give isocoumarins or naphthalenes, depending on the reaction temperature. Moreover, they showed moderate catalytic activity in other annulations of alkynes with aromatic compounds (such as benzamide, acetanilide, etc.) which proceed through CH activation. Compound 2 b also effectively catalyzes the reductive amination of aldehydes and ketones in the presence of carbon monoxide and water via water-gas shift reaction, giving amines in high yields (67-99 %).

Non-symmetrically substituted ruthenocenes CpRuCp´ (Cp´ = C5H4CHO (1a), C5H4COMe (1b), C5H4SiMe3 (1c), 1,3-C5H3(SiMe3)2 (1d), and Cp* (1e)) were synthesized in high yields by the reaction of [CpRu(MeCN)3]+ with cyclopentadienide anions. The structures of complexes 1a,b,d were determined by X-ray diffraction analysis. According to the energy partition analysis data, donor substituents strengthen the interaction between the [RuCp]+ and Cp´– fragments, whereas acceptor substituents weaken the interaction. This bond is predominantly electrostatic (56—59%). Based on the calculated electrostatic potentials at the ruthe-nium nucleus, it is shown that the donor ability of the substituents decreases in the following order: NMe2 > NH2 > OMe > Me ≈ OH > Rc > Fc ≈ Allyl ≈ H > SiMe3 > CH=CH2 ≈ Ph > PH2 > > SH ≈ F > SiH3 ≈ C≡CH > Cl > Br ≈ I ≈ COOMe > COOH > COMe > CF3 > CHO > CN > NO2.

The Raman spectra of single crystalline RE (rare earth) tetraborides RE B 4 ( RE = Y, La, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Lu) are measured and analysed with respect to the dependence of the phonon frequencies on the rare earth metal. Phonons representing octahedral B 6 units are identified by comparison to the according phonon modes of hexaborides. Their relative force parameters are estimated.

The results of the mathematical modeling of granulation from solutions in continuous fluidizedbed apparatuses with an external recycle are given. The analysis of the process using the proposed model is presented, and an example that is of practical interest is given.

Cationic triple-decker complexes [CpCo(1,3-C3B2Me5)Ru(arene)]PF6 (arene is benzene (2a), p-cymene (2b)) with a bridging diborolyl ligand were synthesized by the reaction of the sand-wich anion [CpCo(1,3-C3B2Me5)]− (1) with [(arene)RuCl2]2. The structure of [2b]PF6 was confirmed by X-ray diffraction analysis.

The cationic triple-decker complexes [CpCo(1,3-C3B2Me5)M(C5R5)]+ (M = Rh (2), Ir (3), R = H (a), Me (b)) with the bridging diborolyl ligand were synthesized by the reaction of the sandwich anion [CpCo(1,3-C3B2Me5)]- (1) with the halide complexes [CpMI2]2 or [Cp*MCl2]2 (Cp* = C5Me5). The structures of [2b]PF6 and [3b]PF6 were established by X-ray diffraction. The nature of the metal—diborolyl bond in these complexes was analyzed using the energy decomposition scheme.

The review summarizes the results of the recent author’s research on the synthesis of triple-decker complexes with bridging borole ligand. Electrophilic stacking of sandwich compounds with [(ring)M] n+ (n = 1, (ring)M = (C5R5)Ru, (C4Me4)Co; n = 2, (ring)M = Cp*Co, Cp*Rh, etc.) cationic fragments were used as a general method of synthesis of the complexes. The influence of the substituent at the boron atom on the course of stacking reactions is discussed. The spectral, structural, and electrochemical properties of the complexes synthesized are also considered.

New dinuclear ruthenium manganese complexes of general composition (bpy)2Ru(L)MnClx(H2O)2 (L is 1,10-phenanthroline-5,6-dione, 3,3′-dicarboxy-2,2′-bipyridyl, or bis(pyrazolyl); x = 2 or 4) were synthesized by the reaction of (bpy)2Ru(L) with MnCl2 · 4H2O. These compounds and the starting mononuclear ruthenium complexes were studied by spectrophotometric and electrochemical methods in MeCN. The position of the charge-transfer band RuII → L in the spectra depends on the donor-acceptor characteristics of the ligand L. For the dinuclear complex under study, the formal potentials of reversible one-electron oxidation of RuII are in the range of 0.9–1.2 V (vs. the standard hydrogen electrode), whereas oxidation of MnII occurs at more positive (by 0.1–0.2 V) potentials.

A mathematical model is suggested for the high-frequency heating of a live tissue containing a small malignant tumor. The tumor is preliminarily filled with a polymer to prevent heat extraction by flowing blood. The polymer must contain a dispersed ferromagnetic to ensure inductive heating. The unsteady-state temperature profiles obtained by numerically solving the biothermal equation are used to estimate the degree of thermal destruction of the tumor cells.

Triple-decker complexes CpCo(μ-1,3-C3B2Me5)M(η-7,8-C2B9H11) (M = Rh (3), Ir (4)) were synthesized by the reaction of [CpCo(μ-1,3-C3B2Me5)MBr2]2 (M = Rh, Ir) with Tl[TlC2B9H11]. The structure of 3 was established by X-ray diffraction analysis.

Dicationic triple-decker complexes [CpCo(μ-1,3-C3B2Me5)M(C6H6)]2+ (M = Rh (3), Ir (4)) were synthesized by the reaction of [CpCo(μ-C3B2Me5)MBr2]2 (M = Rh, Ir) with benzene in the presence of AgBF4. The structure of 3(BF4)2 was determined by X-ray diffraction analysis.

The cationic complex [Cp*Ru(C5Me4CH2)]+ reacts with Et3N primarily giving the ammonium salt [Cp*Ru(C5Me4CH2NEt3)]+. The prolonged standing of the reaction mixture results in the formation of the ether Cp*Ru(C5Me4CH2OCH2C5Me4)RuCp*. The reaction of [Cp*Ru(C5Me4CH2)]+ with PhNEt2 leads to the electrophilic aromatic substitution product [Cp*Ru(C5Me4CH2C6H4NHEt2)]+.

A number of earlier unknown tri- and tetranuclear organometallic clusters of group VIII transition metals was synthesized by the addition of coordinatively unsaturated species to a single metal-metal bond. A number of novel heteronuclear clusters, CpCp 2 ′ Rhm2(μ−CO)3(μ3−CO), (Cp′=Cp, Cp*; M2=Ru2, Fe2; RuFe); Cp2Cp 2 * Rh2M2(μ3−CO)3 (M = Ru, Fe); , Cp3Cp*Rh3M(μ3−CO)2(μ3−d) (M = Ru, Fe); Cp2Cp 2 *> Rh2Co2(μ3−CO)2,etc., was obtained.

ISSN 1607-6729, Doklady Biochemistry and Biophysics, 2008, Vol. 421, pp. 214–217. © Pleiades Publishing, Ltd., 2008.Original Russian Text © A.V. Katokhin, S.V. Shekhovtsov, S. Konkow, N.I. Yurlova, E.A. Serbina, S.N. Vodianitskaia, K.P. Fedorov, V.B. Loktev, I.V. Muratov, F. Ohyama,T.V. Makhneva, S.E. Pel’tek, V.A. Mordvinov, 2008, published in Doklady Akademii Nauk, 2008, Vol. 421, No. 4, pp. 549–552.

Hexanuclear rhodium carbonyl cluster, Rh6(CO)16, catalyzes benzene hydroxylation with hydrogen peroxide in acetonitrile solution. Phenol and (at lower concentration) quinone are formed with the maximum attained total yield and turnover number 17% and 683, respectively. Certain other rhodium carbonyl complexes, containing cyclopentadienyl ligands, Rh2Cp2(CO)3 and Rh3(CpMe)3(CO)3, are less efficient catalysts. Cyclopentadienyl derivatives of rhodium which do not contain the carbonyl ligands, Rh(CpMe5)(CH2CH2)2, RhCp(cyclooctatetraene) and Rh2Cp2(cyclooctatetraene) turned out to be absolutely inactive in the benzene hydroxylation. Styrene is transformed into benzaldehyde and (at lower concentration) acetophenone and 1-phenylethanol. Copyright © 2008 John Wiley & Sons, Ltd.

The μ-diborolyl triple-decker complex CpCo(μ-1,3-C3B2Me5)PtMe3 was prepared by reaction of the sandwich anion [CpCo(1,3-C3B2Me5)]–with [PtMe3I]4; according to energy decomposition analysis, attractive interactions between the [CpCo(1,3-C3B2Me5)]– and [PtMe3]+ fragments are ∼64% electrostatic and 36% covalent.

Stacking reactions of the dicationic fragments [LM]2+ (LM = (η-C6H6)Ru, (η-C6H3Me3)Ru, or (η-C5Me5)Rh) with the complex (η-C5H5)Co(η-C4H4BCy) (Cy = cyclo-C6H11) afforded new dicationic 30-electron triple-decker complexes [(η-C5H5)Co(μ-η:η-C4H4BCy)ML](BF4)2 containing a cyclohexyl-substituted borole ligand in the central position.

The first unsymmetrical 34-electron cationic cobalt-nickel triple-decker complex with a central cyclopentadienyl ligand [(η-C6Me6)Co(μ-η:η-C5H5)Ni(η-C5)PF6 was prepared by the reaction of [(η-C6Me6)2Co]PF6 with nickelocene.

The 86-electron dicationic octahedral rhodium cluster [Rh6Cp6(μ6-C)]2+(PF6 -)2 containing Cp ligands and the interstitial carbon atom was synthesized by the reaction of Rh3Cp3(μ-CO)3 with RhCp(C2H4)2

According to IR spectroscopy data, the interaction of bi-, tri-, and tetranuclear cyclopentadienylcarbonyl rhodium complexes with rather weak protic acids (phenols, fluoroalcohols) in low-polarity media results in the formation of hydrogen bonds of the OH...O=C type with bridged carbonyl groups. According to1H NMR data, protonation of these complexes with strong acids (CF3COOH and HBF4) occurs at the the Rh-Rh bond to give the symmetrical\(\begin{array}{*{20}c} {} & {} & H & {} \\ {} & / & {} & \backslash \\ {Rh} & - & - & - \\ {} & {} & {} & {} \\ \end{array} \begin{array}{*{20}c} {} \\ { Rh} \\ \end{array} \) bridge.

The interaction of Cp*M(CO)2 (M=Ir or Rh) with CF3COOH in low polar media results in partial protonation of these compounds giving molecular (M...HO) and ionic (MH+...O−) hydrogen-bonded complexes. According to IR spectral data, a decrease in temperature results in a shift of the equilibrium toward the ionic forms. These compounds react with phenol to give molecular complexes only.

Novel mixed trigonal-bipyramidal clusters [MRh4(η-C5H5)4(PPh3)(μ3-CO)2]+PF6–(M=Cu, Ag, Au) have been prepared by the reaction of Rh4(η-C5H5)(μ,3-CO)2 with [M(PPh3)]+ fragments, generated in situ in CH2CI2 from M(PPh3)Hal.