Unique behaviour of dinitrogen-bridged dimolybdenum complexes bearing pincer ligand towards catalytic formation of ammonia

It is vital to design effective nitrogen fixation systems that operate under mild conditions, and to this end we recently reported an example of the catalytic formation of ammonia using a dinitrogen-bridged dimolybdenum complex bearing a pincer ligand, where up to twenty three equivalents of ammonia were produced based on the catalyst. Here we study the origin of the catalytic behaviour of the dinitrogen-bridged dimolybdenum complex bearing the pincer ligand with density functional theory calculations, based on stoichiometric and catalytic formation of ammonia from molecular dinitrogen under ambient conditions. Comparison of di- and mono-molybdenum systems shows that the dinitrogen-bridged dimolybdenum core structure plays a critical role in the protonation of the coordinated molecular dinitrogen in the catalytic cycle.

Research into molecular catalysts for conversion of nitrogen into ammonia under mild conditions is ongoing. Here, the authors synthesize a dimolybdenum–nitride complex and verify the role of the dimetallic core in the protonation of the coordinated dinitrogen.

Preparation and reactivity of molybdenum-dinitrogen complexes bearing an arsenic-containing ANA-type pincer ligand

Novel mono- and dimolybdenum-dinitrogen complexes bearing an arsenic-containing ANA-type pincer ligand are prepared and characterized by X-ray analyses. These complexes afford a stoichiometric amount of ammonia by treatment with sulfuric acid at room temperature.

Synthesis of nitrogen heterocycles via α-aminoalkyl radicals generated from α-silyl secondary amines under visible light irradiation

We have succeeded in the visible light-mediated synthetic use of α-aminoalkyl radicals derived from α-silyl secondary amines toward addition to α,β-unsaturated carbonyl compounds. The resulting γ-aminocarbonyl compounds are converted into γ-lactams and pyrroles in a one-pot process.

Copper-catalyzed nucleophilic trifluoromethylation of benzylic chlorides

The reactions of primary and secondary benzylic chlorides with trifluoromethyltrimethylsilane in the presence of a catalytic amount of copper(i) thiophene-2-carboxylate (CuTC) have been found to give the corresponding benzylic trifluoromethylated products in good to high yields.

Enantioselective intramolecular propargylic amination using chiral copper–pybox complexes as catalysts

Intramolecular propargylic amination of propargylic acetates bearing an amino group at the suitable position in the presence of chiral copper–pybox complexes proceeds enantioselectively to give optically active 1-ethynyl-isoindolines (up to 98% ee).

Preparation and reactivity of a dinitrogen-bridged dimolybdenum-tetrachloride complex

A dinitrogen-bridged dimolybdenum-tetrachloride complex is prepared and reduced with Super-Hydride (LiBHEt3) to afford the corresponding dimolybdenum-dinitrogen complex together with the formation of molecular dihydrogen. This reaction proceeds via the ligand exchange of the coordinated dihydrogen generated in situ with molecular dinitrogen.

Visible-light-mediated addition of α-aminoalkyl radicals generated from α-silylamines to α,β-unsaturated carbonyl compounds

Visible-light-mediated addition of α-aminoalkyl radicals generated from α-silylamines to α,β-unsaturated carbonyl compounds using a photoredox catalyst is developed. We also succeeded in the isolation of a silyl enol ether as a primary product of the photochemical reaction.