Cross-combination of magnesium diacetylenides with organic halides catalyzed by transition metals complexes

Conclusions The cross-combination of magnesium diacetylenides of the type (R-CC)₂Mg (R=C₅H₁₁, Ph) with alkyl-, allyl-, propargyl-, and arylhalides, catalyzed by Cu(I), Ni, and Pd complexes, gives mono- and disubstituted acetylenes with high yields.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2037–2041, September, 1987.     

Cross coupling of organoaluminum compounds with phenyl allyl sulfone,catalyzed by transition metal complexes

Conclusions A method was developed for obtaining 1-alkenes by reacting di- and trialkylalanes with phenyl allyl sulfone, catalyzed by copper complexes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 675–677, March, 1984.     

Cross coupling of dialkylmagnesium derivatives with allylic compounds catalyzed by copper salts

Conclusions The feasibility was demonstrated for the preparation of unsaturated hydrocarbons of given structure by the cross coupling of dialkyltnagnesium derivatives with functional allylic compounds by the action of catalytic amounts of copper complexes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 211–213, January, 1985.     

Hydrophosphination of alkoxyalkenes catalyzed by transition metal complexes

Diphenylphosphine adds to alkyl vinyl ethers in the presence of Ni(II) and Pd(II) complexes with a high regioselectivity, leading to exclusive formation of the corresponding Markownikoff adducts which were isolated as 1-alkoxyalkyl(diphenyl)phosphine oxides via oxidation with hydrogen peroxide.     

New reaction of enamines with aryldiazoacetates catalyzed by transition metal complexes

The reaction of aryldiazoacetates with enamines catalyzed by copper and rhodium complexes provided γ-keto esters in good yields. A full investigation of the effects of solvents, catalysts, enamines and aryldiazoacetates on the reaction was carried out. Careful analysis of the crude reaction mixture revealed a substituted enamine as the primary product, which was hydrolyzed over silica gel to give a γ-keto ester as the final product. A reaction mechanism involving nucleophilic addition of an enamine to a metal carbene and subsequent hydrogen transfer was proposed. Chiral dirhodium and copper catalysts were examined and found to provide γ-keto esters with no enantioselectivity. The result could be rationalized based on the proposed reaction mechanism. Attempts to trap the enamine intermediate with several electrophilic reagents were not successful.     

Interaction of vinylpyridines with 1,3-dienes catalyzed by transition metal complexes

The linear and cyclic cooligomerization of 2-vinyl-, 2-methyl-5-vinyl-, and 4-vinylpyridines with 1,3-dienes and trienes catalyzed by complexes of transition metals (Fe, Co, Ni, Mn, Cr, Pd, Ru, Rh, and Zr) was carried out to give unsaturated pyridines containing alkenyl and cycloalkenyl substituents.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 916–921, May, 1993.     

Hydroamination of conjugated dienes catalyzed by transition metal complexes

The review summarizes published data on the hydroamination of 1,3-dienes with various primary and secondary amines, ammonia, and ammonium salts of mineral acids in the presence of transition metal complexes under homogeneous conditions. The effects of the nature of metal, ligand, initial diene, and amine and reaction conditions on the selectivity of hydroamination are considered, and possible reaction mechanisms are discussed.     

Reductive depolymerization of plastics catalyzed with transition metal complexes

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New reactions of 1-alkynes catalyzed by transition metal complexes

Recently discovered catalytic reactions with ruthenium and lanthanide metal complexes have extended the scope of 1-alkynes as useful reagents. The specific formation of aryl-substituted (Z)-1,3-enzymes via the dimerization of HC(triple bond) CR(1) (R(1) = aryl) has been attained using dimeric lanthanide complexes, the catalytic activity of which appears to be unaffected by time. The dimerization of HC(triple bond) CR(2) (R(2) = t-Bu, SiMe(3)) catalyzed by Ru(cod)(cot)/PR(3) or RuH(2)(PPh(3))(3) produces a good yield of butatrienes (Z)R(2)CH=C=C=CHR(2) with a high degree of selectivity. Under certain conditions, HC(triple bond) C=SiMe(3) dimerizes to yield exclusively (Z)-M(3)Si-C(triple bond) C-CH=CH-SiMe(3). The hydration of HC(triple bond)CR(3) (R(3) = alkyl, aryl) catalyzed by RuCl(2)/PR'(3) or CpRuCl(PR"(3))(2) has realized the first example of anti-Markovnikov regioselectivity in an addition reaction of water that produces aldehydes R(3)CH(2)bond;CHO. The application of this reaction to propargylic alcohols has lead to their formal isomerization to alpha,beta-unsaturated aldehydes. In contrast, the addition of amines R(4)bond;NH(2) (R(4) = aryl) to HCtbond;CR(5) (R(5) = alkyl, aryl) conforms to Markovnikov's rule to produce ketimines R(5)bond;(C=NR(4))bond;CH(3) when catalyzed by a Ru(3)(CO)(12)/additive. Since the reaction can be performed in air without the need for any solvents, it enables the practical synthesis of aromatic ketimines, which are difficult to prepare by conventional methods. The synthesis of indoles using deactivated anilines is one practical application of this reaction. The mechanisms of some of these reactions have been analyzed in detail with the aid of theoretical calculations.     

Enantioselective oxidative biaryl coupling reactions catalyzed by 1,5-diazadecalin metal complexes

[reaction: see text]. Chiral 1,5-diaza-cis-decalins have been examined as ligands in the enantioselective oxidative biaryl coupling of substituted 2-naphthol derivatives. Under the optimal conditions employing a 1,5-diaza-cis-decalin copper(I) iodide complex with oxygen as the oxidant, rapid and highly selective couplings could be achieved (90-93% ee, 85% yield).     

Homogeneous and biphasic autoxidation of tetralin catalyzed by transition metal salts and complexes

The biphasic autoxidation of tetralin was carried out using various Co, Ni and Mn complexes as catalysts. Cobalt–N,N′-dimethylethylenediamine complex, which is amphiphilic and surface-active, was found to be most effective; it could be easily recovered in a compact emulsion layer after the reaction and could be reused with no apparent loss of activity. The biphasic reaction differs from the homogeneous counterpart in that (1) little hydroperoxide product is formed, (2) there is lesser sensitivity to product inhibition and a greater degree of conversion and (3) there is an easier catalyst recovery and substrate recycle.     

Computational mechanistic studies of acceptorless dehydrogenation reactions catalyzed by transition metal complexes

Acceptorless dehydrogenation (AD) that uses non-toxic reagents and produces no waste is a type of catalytic reactions toward green chemistry. Acceptorless alcohol dehydrogenation (AAD) can serve as a key step in constructing new bonds such as C-C and C-N bonds in which alcohols need to be activated into more reactive ketones or aldehydes. AD reactions also can be utilized for hydrogen production from biomass or its fermentation products (mainly alcohols). Reversible hydrogenation/ dehy-drogenation with hydrogen uptake/release is crucial to realization of the potential organic hydride hydrogen storage. In this article, we review the recent computational mechanistic studies of the AD reactions catalyzed by various transition metal complexes as well as the experimental developments. These reactions include acceptorless alcohol dehydrogenations, reversible dehydrogenation/hydrogenation of nitrogen heterocycles, dehydrogenative coupling reactions of alcohols and amines to construct C-N bonds, and dehydrogenative coupling reactions of alcohols and unsaturated substrates to form C-C bonds. For the catalysts possessing metal-ligand bifunctional active sites (such as 28, 45, 86, 87, and 106 in the paper), the dehydrogenations prefer the "bifunctional double hydrogen transfer" mechanism rather than the generally accepted-H elimination mechanism. However, methanol dehydrogenation involved in the C-C coupling reaction of methanol and allene, catalyzed by the iridium complex 121, takes place via the-H elimination mechanism, because the Lewis basicity of either the-allyl moiety or the carboxyl group of the ligand is too weak to exert high Lewis basic reactivity. Unveiling the catalytic mechanisms of AD reactions could help to develop new catalysts.     

Recent progress in transition metal catalyzed cross coupling of nitroarenes

The recent development in transition metal catalyzed cross coupling of nitroarenes was highlighted. And nitroarenes were efficient electrophilic coupling partners for constructing C–O, C–S, C—C and C–N bonds.     

Hydromagnesation of unsaturated compounds using diethylamino-magnesium hydride,catalyzed by transition metal complexes

Conclusions Diethylaminomagnesium hydride in the presence of Cp₂TiCl₂ regioselectively hydromagnesates 1-alkenes to give diethylaminomagnesium alkyls.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1901–1903, August, 1983.     

Polycondensation vs. cyclization of divinylsubstituted silicon compounds catalyzed by transition metal complexes

In the presence of ruthenium complexes divinyldiorganosilicon compounds undergo de‐ethenated coupling polycondensation yielding under optimum conditions trans‐tactic polysilylene(siloxylene, silazanylene)vinylenes and poly(silylene‐arylene‐vinylenes). Rhodium‐ ([RhX(cod)]₂ X = Cl, OSiMe₃) catalyzed ring closure of oligomeric (dimeric, trimeric) products of intermolecular condensation opens a new route to synthesizing organosilicon exo‐cyclic methylenes. In the presence of Ru‐complexes the cross‐coupling (poly)condensation of di‐ and trivinylsilicon monomers with organic dienes allows syntheses of a series of linear and dendrimeric poly(arylene‐silylene‐vinylene)s.     

First enantioselective allylic etherification with phenols catalyzed by chiral ruthenium bisoxazoline complexes

Regio- and enantioselective substitution of cinnamyl chloride by phenols has been achieved with up to 82% enantiomeric excess, using a ruthenium catalyst prepared from [Cp*(CH(3)CN)(3)Ru][PF(6)] and a chiral bisoxazoline ligand.     

Synthesis of aryl-substituted pyridines by liquid-phase condensation of aldehydes with urea,catalyzed by transition metal complexes

Conclusions The synthesis of a series of 2,3,5-substituted pyridine bases was carried out by reaction of aldehydes with urea in the presence of a Co(2-ethylhexanoate)₂-Al(C₂H₅)₃ system.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2335–2340, October, 1988.