Nickel-Catalyzed Reductive Addition of Aryl/Benzyl Halides and Pseudohalides to Carbodiimides for the Synthesis of Amides

Nickel(I)-Phenolate Complexes: The Key to Well-Defined Ni(I) Species

Phosphine-stabilized monovalent nickel complexes play an important role in catalysis, either as catalytically active species or as decomposition products. Most routes to access these complexes are highly ligand specific or rely on strong reducing agents. Our group recently disclosed a path to access nickel(I)-phenolate complexes from bis(1,5-cyclooctadiene)nickel(0) (Ni(cod)2). Herein, we demonstrate this protocol's broad applicability by ligating a wide range of mono- and bidentate phosphine ligands. We further show the versatility of the phenolate fragment as a precursor to nickel(I)-alkyl or aryl species, which are relevant to Ni catalysis or synthetically useful nickel(I)-chloride and hydride complexes. We also demonstrate that the chloride complex can be synthesized in a one-pot procedure starting from Ni(cod)2 in good yield, making this protocol a valuable alternative to current procedures. Single-crystal X-ray diffraction, IR, and EPR (or NMR) spectroscopy were employed to characterize all of the synthesized nickel complexes.

CuO-decorated magnetite-reduced graphene oxide: a robust and promising heterogeneous catalyst for the oxidative amidation of methylarenes in water via benzylic sp3 C–H activation

CuO-decorated magnetite-reduced graphene oxide: a heterogeneous catalyst for the oxidative amidation of methylarenes in water at room temperature.

Nickel-catalyzed reductive amidation of aryl-triazine ethers

The reaction of activated phenolic compounds, 2,4,6-triaryloxy-1,3,5-triazine (aryl-triazine ethers), with various isocyanates or carbodiimides in the presence of a nickel pre-catalyst resulted in the synthesis of aryl amides in good to excellent yields.

Nickel-Catalyzed Reductive Etherification of Aldehydes at Room Temperature: C-O vs C-C Bond Formation

The reaction of secondary and tertiary benzyl alcohols activated by 2,4,6-trichloro-1,3,5-triazine (TCT) with aldehydes in the presence of NiCl₂·dmg as a precatalyst in ethylene glycol afforded ethers at room temperature. A selective C-O vs C-C bond formation was observed for the secondary and tertiary benzyl alcohols in comparison with primary ones.

TBHP-mediated highly efficient dehydrogenative cross-oxidative coupling of methylarenes with acetanilides

A TBHP-mediated dehydrogenative cross-oxidative-coupling approach has been developed for the synthesis of N-arylbenzamides from methylarenes and acetanilides. This cross-coupling method is free of transition metal catalysts and ligands, and no extra organic solvents are required, which make it an useful and attractive strategy for the straightforward construction of C–N bonds. Besides, this conversion is an important complement to the conventional C–N forming strategies.