Phosphorus ligand-free Suzuki–Miyaura reactions in the presence of ABTS at room temperature in water

A catalytic system for a phosphorus ligand-free Suzuki–Miyaura reaction in water at room temperature was disclosed. Ammonium 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonate) (ABTS) was an efficient promoter and acted both as a ligand and as a surfactant for the synthesis of biaryl compounds via the Suzuki–Miyaura reaction in water. The targeted biaryl architectures were achieved under mild conditions with high efficiency and good functional group tolerance.

Enamine catalysis

The reversible reaction of primary or secondary amines with enolizable aldehydes or ketones affords nucleophilic intermediates, enamines. With chiral amines, catalytic enantioselective reactions via enamine intermediates become possible. In this review, structure-activity relationships and the scope as well as current limitations of enamine catalysis are discussed.