No abstract

Allylcopper intermediates with N-heterocyclic carbene ligands are synthesized by transmetalation of allylsiloxane reagents, and the crystal structures of allylcopper compounds are reported. The allylcopper transmetalation is utilized for catalytic aldehyde allylation, which is found to be facilitated by a trifluorosilane co-catalyst.

A (pyridyl)­phosphine-ligated ruthenium­(II) catalyst is reported for the chemoselective benzylic N-alkylation of amines, via a hydrogen-borrowing mechanism. The catalyst operates under mild conditions, neat, and without a base or other additive. These conditions offer remarkable functional group compatibility for applications in organic synthesis, including reactions involving phenols and anilines, which are very difficult to achieve. Mechanistic studies suggest that, unlike other catalysts for this reaction, the redox steps are fast and reversible while imine formation is slow. We perceive that this is the origin of the selectivity realized with these reaction conditions.

Exploring the stacks: Two different but related naphthalene compounds were shown to form different nanostructures (see picture) depending on the π–π stacking and hydrogen bonding of the molecules. These nanostructures had unique photonic confinement and light‐propagation characteristics, which show potential for nanophotonic circuits.

Novel sulfoxide-ligated ruthenium complexes were prepared by reacting second-generation metathesis precatalysts with p-toluenesulfonyl chloride in the presence of a small excess of sulfoxide. (SIMes)Ru(S-DMSO)(Ind)Cl 2 (M54) and (SIMes)Ru(S-DMSO)(CHPh)Cl 2 (M54a) were characterized crystallographically and, in agreement with NMR spectroscopy, were found to adopt an unusual cis-dichloro configuration. Despite having traditionally latent geometry, the new complexes were found to be highly reactive precatalysts for routine metathesis transformations. Additionally, the robustness, scalability, and industrial utility of M54 as a ruthenium synthon are demonstrated.