Synthesis, Structure, and Conformational Dynamics of Rhodium and Iridium Complexes of Dimethylbis(2-pyridyl)borate.

Rhodium(I) and Iridium(I) borate complexes of the structure [MeB(2-py)]ML (L = (tBuNC), (CO), (CH), cod, dppe) were prepared and structurally characterized (cod = 1,5-cyclooctadiene; dppe = 1,2-diphenylphosphinoethane). Each contains a boat-configured chelate ring that participates in a boat-to-boat ring flip. Computational evidence shows that the ring flip proceeds through a transition state that is near planarity about the chelate ring.

Synthesis and Characterization of Dimethylbis(2-pyridyl)borate Nickel(II) Complexes: Unimolecular Square-Planar to Square-Planar Rotation around Nickel(II).

The syntheses of novel dimethylbis(2-pyridyl)borate nickel(II) complexes and are reported. These complexes were unambiguously characterized by X-ray analysis. In dichloromethane solvent, complex undergoes a unique square-planar to square-planar rotation around the nickel(II) center, for which activation parameters of Δ = 12.

A Ruthenium-Catalyzed Coupling of Alkynes with 1,3-Diketones.

Ruthenium(III) chloride hydrate is a convenient catalyst for the addition of active methylene compounds to aryl alkynes. These reactions are rapid, operationally simple, and high yielding in cases. Most significantly, no precautions are required to exclude air or water from the reactions.