Oxime-Derived Palladacycles: Applications in Catalysis

Phenone oxime-derived palladacycles are stable, easy to prepare, and an excellent source of three- and four-atom Pd clusters able to show excellent catalytic activity in most of the classical carbon–carbon bond forming reactions (Mizoroki–Heck, Matsuda–Heck, Suzuki–Miyaura, Stille, Kumada, Hiyama, Ullmann, Sonogashira, and Glasser), generally with better performance than Pd(OAc)2 or other Pd salts. Aryl iodides, bromides, chlorides, and imidazolyl sulfonates can be used as substrates not only in organic solvents but also in aqueous solvents including neat water. Appropriate choice of the general reaction conditions allow these C−C bond forming reactions to be performed efficiently. These palladacycles have been also used in carbonylations, several types of annulations, ketone arylations, C−H activation, oxime rearrangements, and behave as metalloenzymes in hydrolytic processes, among others. Not only dimer complexes can be used, but also monomer ones with an additional ligand as well as those supported on polymers, silica, and bearing ionic or fluorinated tags.The Spanish Ministerio de Ciencia e Innovación (MICINN) (projects BQ2001-0724, CTQ2004-00808, CTQ 2007-62771/BQU, Consolider Ingenio 2010, CSD2007-00006, CTQ2010-20387), Spanish Ministerio de Economia y Competitividad (MINECO) (projects CTQ2013-43446-P and CTQ2014-51912-REDC), FEDER, the Generalitat Valenciana (PROMETEO 2009/039 and PROMETEOII/2014/017), and the University of Alicante are gratefully acknowledged for financial support