N-Heterocyclic carbenes as highly efficient ancillary ligands in homogeneous and immobilized metathesis ruthenium catalytic systems

Abstract

Dedicated to Professor Alexandru T. Balaban on the occasion of his AbstractThis general overview focuses on novel N-heterocyclic carbene (NHC) Ru complexes, now at the forefront of research in metathesis chemistry, and on their derived multiple applications in targeted organic, polymeric and natural compound synthesis. This outstanding, large class of ruthenium precatalysts combines high activity and selectivity with increased stability and good tolerance towards organic functionalities, air and moisture. The NHC ancillary ligands allow manipulation of the catalytic performance through adjustment of electronic and steric parameters in the ruthenium coordination sphere, facilitate introduction of chiral motifs, and enable convenient immobilization of homogeneous initiators onto solid supports. A broad spectrum of practical applications is discussed.