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α-Alkylation reactions between amides and alcohols, with dimethylacetamide-stabilized Ru nanoparticles (NPs) as the catalyst, were investigated. The reactions proceeded with low catalyst loadings compared to metal complexes. Characterizations of the Ru NPs were performed by X-ray photoelectron spectroscopy, X-ray absorption fine structure spectroscopy, and various techniques. Control experiments revealed the reaction mechanisms, which proceeded

This paper reports novel Cu-catalyzed three-component coupling reactions using nitriles, 1, 3-dienes and silylboranes. The desired reactions proceed at room temperature and yield β, γ-unsaturated ketones with a (dimethylphenylsilyl)methyl moiety at the α-position. Diverse nitriles participate in the reaction and the corresponding products were obtained in good to high yields with high regioselectivity.

A bulky carboxylic acid bearing one 1-adamantylmethyl and two methyl substituents at the α-position is demonstrated to work as an efficient carboxylate ligand source in Pd-catalyzed intermolecular C(sp2)-H bond arylation reactions. The reactions proceeded smoothly under mild conditions, taking advantage of the steric bulk of the carboxylate ligands.

π-Conjugated porphyrin-containing hollow structures with defined axis-length were successfully synthesized by a two-step template method, i.e., template-assisted cyclization and oligomerization. During the oligomerization, templates played important roles in controlling the reaction rates and the axis lengths. The hollow structures exhibited an extended effective π-conjugation because of the high coplanarity between porphyrins.

A highly selective carbon-carbon bond-forming transformation of carbon dioxide (CO2) to alcohol oxidation level has been disclosed. By employing a copper/bisphosphine catalyst system and hydrosilanes as mild and easy-to-handle reducing agents, various allenes can be reacted with CO2 to regioselectively obtain homoallylic alcohols. Esters and other reducible functionalities on the allenes remain intact during the reaction, whereas CO2 is reduced to alcohol oxidation level.

N-Heterocyclic carbenes bearing poly(ethylene glycol) chains of different lengths have been designed and employed as ligands in palladium-catalyzed coupling reactions. The catalyst system having longer chains was found to be highly efficient for Suzuki-Miyaura coupling and borylation reactions employing aryl chlorides under mild reaction conditions.

Palladium-catalyzed formal arylacylation of allenes using acid chlorides and arylboronic acids has been achieved. The reaction afforded the corresponding α, β-unsaturated ketones regio- and stereoselectively.

A series of novel imidazolium salts bearing hydrophilic tetraethylene glycol (TEG) and/or hydrophobic long-chain alkyl (n-C12) functionalities, which are precursors for desired N-heterocyclic carbene (NHC) ligands, were synthesized and characterized. Rh(I)-NHC complexes were prepared in good yields by the silver carbene transfer method with NHC-Ag species derived from the imidazolium salts. The molecular structure of the Rh(I)-NHC complex having n-C12 chains has been determined by a single-crystal X-ray diffraction study and the complex is found to possess extended alkyl chains with anti conformations in the solid state. Hydrosilylation with the Rh(I) complexes and Suzuki-Miyaura coupling reactions with the Pd(II) complexes with these NHC ligands were carried out. In the latter case, the TEG moiety enhances catalytic activity considerably.

The synthesis and electrochemical properties of a Ru(II) complex having a redox active ligand, 1,10-phenanthroline-5,6-dione, [Ru(trpy)(PD-N,N′)Cl](PF6) ([1](PF6)), and mixed-metal complexes [(PPh3)2Pd(O,O′-PD-N,N′)Ru(trpy)Cl](PF6) ([2](PF6)) and [(PPh3)2Pt(O,O′-PD-N,N′)Ru(trpy)Cl](PF6) ([3](PF6)) (trpy = 2,2′:6′,2″-terpyridine, PD = 1,10-phenanthroline-5,6-dione) are presented. The complex of [1]+, which was prepared by the reaction of Ru(trpy)(DMSO)Cl2 with PD in hot ethanol, underwent two reversible reductions in the PD-based redox reactions. The quinoid moiety of [1]+ was endowed with coordination ability to metals by one- and two-electron reduction of the complex. The mixed-metal complexes of [2]+ and [3]+ were synthesized by the reactions of [1]+ with M(PPh3)4 (M = Pd, Pt), and both complexes have the [1]− and M(II) frameworks.

We developed a new method for the synthesis of an organic-soluble insulated molecular wire (IMW) with permethylated cyclodextrin (PMCD); this method involves click polymerization of linked [2]rotaxane containing azide and alkynyl groups at both ends of a π-conjugated guest.

Recent carbon-carbon bond forming reactions of carbon dioxide with alkenes, alkynes, dienes, aryl zinc compounds, aryl boronic esters, aryl halides, and arenes having acidic C-H bonds are reviewed in which transition-metal catalysts play an important role.

Rh(III) complexes with a bidentate N-heterocyclic carbene ligand bearing flexible dendritic frameworks have been synthesized and fully characterized by X-ray crystallographic analysis, NMR measurements and theoretical calculations.

Novel dendrimer N-heterocyclic carbene complexes with rhodium(I) located at the core were synthesized, and a positive dendrimer effect was found in the hydrosilylation of ketones catalyzed by them.