Alkylation Reactions of Azodicarboxylate Esters with 4-Alkyl-1,4-Dihydropyridines under Catalyst-Free Conditions

Introduction of alkyl groups on azodicarboxylate esters is an important method to prepare alkyl amine derivatives. Herein, we report reactions of 4-alkyl-1,4-dihydropyridines as alkylation reagents with di- tert-butyl azodicarboxylate to prepare alkyl amine derivatives under heating conditions. The alkylation reactions via C-C bond cleavage of the dihydropyridines are achieved in the absence of catalysts and additives.

Catalytic C-H Borylation Using Iron Complexes Bearing 4,5,6,7-Tetrahydroisoindol-2-ide-Based PNP-Type Pincer Ligand

Catalytic C-H borylation has been reported using newly designed iron complexes bearing a 4,5,6,7-tetrahydroisoindol-2-ide-based PNP pincer ligand. The reaction tolerated various five-membered heteroarenes, such as pyrrole derivatives, as well as six-membered aromatic compounds, such as toluene. Successful examples of the iron-catalyzed sp³ C-H borylation of anisole derivatives were also presented.

Copper-Catalyzed [3+2] Cycloaddition Reactions of Isocyanoacetates with Phosphaalkynes to Prepare 1,3-Azaphospholes

A novel copper-catalyzed synthetic method is described for phosphorous- and nitrogen-containing heterocycles such as 1,3-azaphospholes. Cycloaddition reactions of various isocyanoacetates with phosphaalkynes in the presence of copper bromide, bis(diphenylphosphino)methane (dppm), and potassium carbonate afford the corresponding 1,3-azaphospholes in high yields with complete selectivity. Some dppm-bridged dicopper complexes were identified as active species for the formation of 1,3-azaphospholes.

Copper-catalysed enantioselective intramolecular etherification of propargylic esters: synthetic approach to chiral isochromans

The first example for direct synthesis of chiral terminal alkynyl isochromans.

Effect of substituents on molybdenum triiodide complexes bearing PNP-type pincer ligands toward catalytic nitrogen fixation

Molybdenum triiodide complexes bearing phenyl and ferrocenyl substituted PNP-type pincer ligands acted as more effective catalysts toward ammonia production under ambient reaction conditions.

Phosphine Oxidation with Water and Ferrocenium(III) Cation Induced by Visible-Light Irradiation

Stoichiometric oxidation of phosphines with water and ferrocenium(III) cation as the oxygen atom source and the oxidizing reagent, respectively, was achieved in acetonitrile under visible-light irradiation by using 2,6-lutidine as the proton acceptor. The reaction required light irradiation, under which fluorescence was observed for the acetonitrile solution of the ferrocenium(III) cation.

Development of catalytic nitrogen fixation using transition metal-dinitrogen complexes under mild reaction conditions

This paper describes our recent progress in catalytic nitrogen fixation using transition metal-dinitrogen complexes as catalysts. Our research group has recently developed novel reaction systems for the catalytic transformation of molecular dinitrogen into ammonia and hydrazine using molybdenum-, iron-, cobalt- and vanadium-dinitrogen complexes under mild reaction conditions. The new findings presented in this paper may provide a new approach to the development of economical nitrogen fixation to replace the energy-consuming Haber-Bosch process.

Synthesis and reactivity of titanium- and zirconium-dinitrogen complexes bearing anionic pyrrole-based PNP-type pincer ligands

Dinitrogen-bridged dititanium and dizirconium complexes bearing anionic pyrrole-based PNP-type pincer ligands are prepared and characterized by X-ray analysis. Their catalytic activity is investigated toward reduction of nitrogen gas into ammonia and hydrazine under mild reaction conditions.

Synthesis and reactivity of iron-dinitrogen complexes bearing anionic methyl- and phenyl-substituted pyrrole-based PNP-type pincer ligands toward catalytic nitrogen fixation

Iron-dinitrogen complexes bearing methyl- and phenyl-substituted pyrrole-based anionic PNP-type pincer ligands are prepared and characterized by X-ray analysis. The former complex is found to work as a more effective catalyst than that bearing a non-substituted PNP-type pincer ligand toward the transformation of nitrogen gas into ammonia and hydrazine under mild reaction conditions.

Preparation and reactivity of iron complexes bearing anionic carbazole-based PNP-type pincer ligands toward catalytic nitrogen fixation

Newly prepared iron complexes bearing carbazole-based PNP-type pincer ligands are found to work as catalysts toward nitrogen fixation.

Mechanism and reactivity of catalytic propargylic substitution reactions via metal–allenylidene intermediates: a theoretical perspective

The mechanism and reactivity of transition metal-catalyzed propargylic substitution reactions are summarized from a theoretical point of view.

Practical Synthesis of a PCP-Type Pincer Ligand and Its Metal Complexes­

A synthetic method for N-heterocyclic carbene- and phosphine-based PCP-type pincer ligand is described on a large scale. Some transition-metal complexes bearing the PCP-type pincer ligand are prepared and characterized by X-ray crystal structure analysis.