Novel [4 + 2] Cycloaddition Reactions of Alkyne and Enyne Key-Units: Direct Access to Bicyclic Aromatic and Heteroaromatic Products. A Theoretical Mechanistic Study

Ananikov V. P., Gordeev E. G., Chem. Sci., 2011, 2, 2332-2341.
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A new efficient approach was developed for the synthesis of aromatic and heteroaromatic compounds based on [4 + 2] cycloaddition of unsubstituted and heteroatom-substituted alkyne and enyne units. The developed approach provides a practical Green chemical route to several types of important bicyclic products (indane, cyclopentapyridines, indole, isoindole, indolizine, isophosphindole, benzofuran, benzothiophene, benzoselenophene and corresponding dihydro derivatives) starting from simple linear compounds. The mechanism of the reactions was revealed by theoretical calculations using different methods, including CCSD(T) and MP4(SDTQ) for energy calculations and B3LYP, M052X, B3PW91, BLYP and MP2 levels for evaluation of molecular structures.

Characterization of Molecular Systems and Monitoring of Chemical Reactions in Ionic Liquids by Nuclear Magnetic Resonance Spectroscopy

Ananikov V. P., Chem. Rev., 2011, 111, 418-454.
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Transition-Metal-Catalyzed C-S, C-Se, and C-Te Bond Formation via Cross-Coupling and Atom-Economic Addition Reactions

Beletskaya I. P., Ananikov V. P., Chem. Rev., 2011, 111, 1596-1636.
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NMR Analysis of Chiral Alcohols and Amines: Development of Environmentally Benign "In Tube" Procedure with High Efficiency and Improved Detection Limit

Orlov N. V., Ananikov V. P., Green Chem., 2011, 13, 1735-1744.
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A fast and efficient approach was developed for the NMR analysis of chiral alcohols and amines using readily available enantiopure MPA (α-methoxy-α-phenylacetic acid) and MTPA (α-methoxy-α-trifluoromethylphenylacetic acid) as chiral derivatizing agents. The procedure requires less than 5 min (including sample preparation time) for analysis using routine NMR hardware and allows accurate measurements for <0.01 mg of the sample of chiral compounds. Direct "in tube" analysis can be performed with high efficiency to determine enantiomeric purity and absolute configuration, as well as to monitor reactions in asymmetric synthesis and catalysis. The developed procedure is superior in terms of waste-free analysis of chiral compounds for environmentally benign applications.

Catalytic (Ni, Pd, Pt, Rh and Au) and Non-Catalytic Reactions for Atom-Economic Carbon-Sulfur, Carbon-Selenium and Carbon-Tellurium Bonds Formation

Ananikov V.P., Zalesskiy S.S., Beletskaya I.P., Curr. Org. Synth., 2011, 8, 2-52.
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Non-catalytic and catalytic addition reactions were compared in this review, with a special attention paid to the factors controlling selectivity and yields. The scope and limitations of Ni, Pd, Pt, Rh and Au catalysts for the formation of C-S, C-Se and C-Te bonds were discussed with an impact of development of Green chemical methods.

Alkyne Insertion into the M-P and M-H Bonds (M = Pd, Ni, Pt, and Rh): A Theoretical Mechanistic Study of the C-P and C-H Bond-Formation Steps

Ananikov V. P., Beletskaya I. P., Chem. Asian. J., 2011, 6, 1423-1430.
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In hydrogen-metal-phosphorus (H[BOND]M[BOND]P) transition metal complexes (proposed as intermediates of H[BOND]P bond addition to alkynes in the catalytic hydrophosphorylation, hydrophosphinylation, and hydrophospination reactions), alkyne insertion into the metal-hydrogen bond was found much more facile compared to alkyne insertion into the metal-phosphorus bond. The conclusion was verified for different metals (Pd, Ni, Pt, and Rh), ligands, and phosphorus groups at various theory levels (B3LYP, B3PW91, BLYP, MP2, and ONIOM). The relative reactivity of the metal complexes in the reaction with alkynes was estimated and decreased in the order of Ni>Pd>Rh>Pt. A trend in relative reactivity was established for various types of phosphorus groups: PR2>P(O)R2>P(O)(OR)2, which showed a decrease in rate upon increasing the number of the oxygen atoms attached to the phosphorus center.

Can We Predict the Future of Organometallic Chemistry?

Beletskaya I. P., Ananikov V. P., Organometallics, 2011, 30, 5-6.
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An essay is presented about the future development of organometallic chemistry and the role of transition-metal catalysis.

Preparation of Metal "Nanosalts" and Their Application in Catalysis: Heterogeneous and Homogeneous Pathways

Ananikov V.P., Beletskaya I.P., Dalton Trans., 2011, 40, 4011-4023.
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A novel type of nanoparticles have been designed based on self-organization of the metal centers with organic functional groups. Size- and shape-controlled synthetic procedures were developed to prepare nanostructured Pd and Ni particles in high yields from easily available precursors. The presence of the non-metallic functional groups in the particle's core forced the metal centers to adopt a divalent oxidation state bearing polar chemical bonds ("nanosalt"). The Pd and Ni particles were excellent catalysts to accomplish a highly selective synthetic route to vinyl chalcogenides. The mechanisms of the catalytic reactions via the heterogeneous and homogeneous pathways were revealed and studied in detail.

Modeling of NMR Spectra and Signal Assignment Using Real-Time DFT/GIAO Calculations

Belaykov P. A., Ananikov V. P., Rus. Chem. Bull., Int. Ed., 2011, 5, 765-771.
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An automated algorithm for fast quantum chemical modeling of NMR spectra within the framework of the density functional theory was developed. High accuracy of calculations of NMR parameters achieved for various classes of organic compounds including heterocyclic compounds, carbohydrates, steroids, and peptides is comparable with the accuracy of experimental determination. The efficiency of computing the NMR chemical shifts using the high-performance PBE/PRIRODA method was demonstrated.

NMR Approach for the Identification of Dinuclear and Mononuclear Complexes: The First Detection of [Pd(SPh)2(PPh3)2] and [Pd2(SPh)4(PPh3)2] - The Intermediate Complexes in the Catalytic Carbon-Sulfur Bond Formation Reaction

Ananikov V.P., Zalesskiy S.S., Kachala V.V., Beletskaya I.P., J. Organomet. Chem., 2011, 696, 400-405.
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In the present study we have analyzed the nature of palladium complexes in the catalytic system for selective carbon–sulfur bond formation via the addition of S–S and S–H bonds to alkynes. For the first time the mononuclear and dinuclear palladium complexes were clearly detected by DOSY NMR under the catalytic conditions. It was demonstrated that the concentration of these palladium complexes strongly depends on the amount of phosphine ligand available under reaction conditions

Highly Selective Catalytic Synthesis of E,E-1,4-Diiodobuta-1,3-diene via Atom-Efficient Addition of Acetylene and Iodine. A Versatile E,E-1,3-Diene Building Block in Cross-Coupling Reactions

Ananikov V.P., Kashin A. S., Hazipov O. V., Beletskaya I. P., Starikova Z. A., Synlett, 2011, 2021-2024.
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The first practical procedure is reported for the synthesis of (E,E)-1,4-diiodobuta-1,3-diene from very simple starting materials (acetylene and I2). A pure crystalline product was obtained in a green chemical procedure utilizing the key advantages of highly selective Pt-catalyzed transformation and 100% atom efficiency of the addition reaction. The Pt catalyst was recovered and re-used in the reaction without a noticeable loss of activity.

The Unique Role of Orientation and Properties of Phosphorus Group in the Alkyne Insertion Step Related to Catalytic Hydrofunctionalization via P-H Bond Addition

Ananikov V. P., Makarov A. V., Beletskaya I. P., Chem. Eur. J, 2011, 17, 12623-12630.
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The puzzling question of alkyne insertion into Pd[BOND]P and Pd[BOND]H bonds leading to the formation of new Pd[BOND]C, C[BOND]P, and C[BOND]H bonds was explored by theoretical calculations at the CCSD(T) and B3LYP levels of theory. The key factors responsible for selectivity of catalytic hydrofunctionalization of alkynes were resolved and studied in details for the models of hydrophosphorylation, hydrophosphinylation, and hydrophospination reactions. In contrast with the generally accepted mechanistic picture, the calculations have shown that several pathways are possible depending on the nature and geometrical arrangement of the phosphorus group. It was found that the product of alkyne insertion into the metal–hydrogen bond should be easily formed under kinetic-control conditions, while the product of alkyne insertion into the metal–phosphorus bond may be formed in certain cases under thermodynamic control. For the first time, the calculations have revealed the role of the oxygen atom in the reactivity of P=P(O)R2 groups and the role of the interactions involving the lone pair of the P=PR2 group in the reagent. The fundamental properties of the Pd[BOND]P, C[BOND]P, and P[BOND]H bonds were reported, and the larger bond strength upon increasing the number of oxygen atoms bound to phosphorus (P=PR2, P(O)R2, and P(O)(OR)2) have been shown. The relationship between bond energy, acidity, and reactivity of the studied phosphorus compounds has been determined.

1,4-Diiodo-1,3-dienes: Versatile Reagents in Organic Synthesis

Ananikov V.P., Hazipov O. V., Beletskaya I.P., Chem. Asian J., 2011, 6, 306-323.
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1,4-Diiodo-1,3-dienes are unique reagents in organic synthesis and have been employed in several well-known and recently developed areas of application. Furthermore, these dienes are easily accessible, starting from the alkynes and iodine, and they have demonstrated high reactivity in cross-coupling reactions, organometallic synthesis, in the preparation of heterocyclic compounds, and several other transformations. The high reactivity of the 1,4-diiodo-1,3-dienes allows for the development of synthetic procedures that use mild conditions (room temperature). The key advantages in assembling complex organic molecules, natural products, and compounds for material science using 1,4-diiodo-1,3-dienes as building blocks include high yields, excellent selectivity, and diverse reactivity in carbon[BOND]carbon and carbon[BOND]heteroatom bond formation. This Focus Review describes the scope and application of the 1,4-diiodo-1,3-dienes in organic synthesis as well as summarizes the methods for preparation of the dienes.