Sila- and Germametallacycles of Late Transition Metals

Abstract

This article reviews recent advances in late-transition-metal complexes with chelating Si and Ge ligands. Compounds with two Si−H bonds, such as bis(silyl)alkanes, bis(silyl)arenes, and tetramethyldisiloxanes, react with Re, Rh, Ir, Pd, and Pt complexes to form disilametallacycles with five- or six-membered chelate rings. Four- and five-membered disilacycloalkanes and disilanyldiylcarboranes undergo Si−Si bond cleavage promoted by Pd(0) and Pt(0) complexes to produce the corresponding disilametallacycles. High reactivity of the Si−Si bond toward oxidative addition facilitates the above ring enlargement, even for compounds with stable five-membered rings. Platinum complexes with a η2-silene ligand react with small molecules having electronegative atoms, such as O2 and NH3, to produce metallacycles formed via addition of the electronegative atom to the Si−Si bond. The above disilametallacycles undergo insertion of alkynes and carbonyl compounds into the M−Si bonds of the disilametallacycles. The persilyl me...