Carbonyl and olefin adducts of coinage metals supported by poly(pyrazolyl)borate and poly(pyrazolyl)alkane ligands and silver mediated atom transfer reactions

We have attempted to provide an overview of a growing area of investigation of the use of modified tris(pyrazolyl)borates and related pyrazole-based ligands, which confer not only useful stabilities on a range of complexes including coinage metal adducts of carbon monoxide and olefins, which permits their isolation and even structural characterization, but also lead to some unusual reactivity profiles. In particular, we have highlighted the chemistry of some silver complexes in carbene transfer reactions, putting their chemistry in context with earlier work. To date, only limited descriptions have appeared in the literature, but it is anticipated that the chemistry described herein will provide the inspiration for other applications of these and related complexes in synthesis. © 2008 American Chemical Society.