Anion influences on the structures of pyridyl-iminosulfonate copper(II) complexes and their reactivity in Chan–Lam couplings

Reaction of pyridylcarbaldehyde with taurine or orthanilic acid in the presence of copper salts provided copper complexes (PyC(H)N-CxHy-SO3)CuX with X = chloride, nitrate, acetate, or triflate and CxHy = o-C6H4 or C2H4. All complexes were characterized by single crystal X-ray diffraction and formed either mononuclear water adducts, dimeric complexes, or one-dimensional coordination polymers. Activities in the Chan–Lam coupling of aniline with phenylboronic acid varied by less than a factor of two between catalysts with various anions, supporting previous mechanistic claims that the anion does not participate in the formation of copper–boron intermediates. There is no difference in the performance of a catalyst with an alkyl backbone, indicating that sulfonate dissociation is not part of the catalytic cycle.

Residue dependent hydrogen-bonding preferences in orthanilic acid-based short peptide β-turn motifs

This communication describes the competition between native β-turn (C10) and 2-aminobenzenesulfonic acid (SAnt)(orthanilic acid)-based pseudo β-turn (C11) in their hybrid peptides.

Two-Dimensional Coordination Polymers in Rubidium and Caesium Complexes with Orthanilic Acid

The crystal structures of the rubidium and caesium complexes with 2-aminobenzenesulfonic acid (orthanilic acid), [Rb4(C6H6NO3S)4(H2O)]n(1) and [Cs(C6H6NO3S)]n(2), have been determined at 200 K. Complex 1 has a repeating unit comprising four independent and different Rb coordination centres, (RbO8), (RbO7), (RbN2O4) and (RbO10), each having irregular stereochemistry and involving several bidentate chelate sulfonate-O,O′-metal and bridging interactions, giving a two-dimensional polymeric layered structure. Anhydrous complex 2 is also polymeric with the irregular (CsO7) coordination polyhedron comprising six sulfonate oxygen donors from three separate bidentate chelate sulfonate ligands and one monodentate bridging sulfonate oxygen, giving a two-dimensional layered structure.