Carbene insertion into transition metal-carbon bonds: a new tool for catalytic C-C bond formation

In this perspective we highlight the applicability of migratory carbene insertion reactions into
TM-C bonds as a new tool for catalytic C-C bond formation. In Section 1 we introduce the
reaction, wherein we also discuss the applicability of transition metal carbene formation from
reactive carbene precursors. In Section 2 we summarise the available mechanistic information
about this elementary step derived from stoichiometric model reactions. In Section 3 we review
the available catalytic examples, with a focus on new developments in palladium mediated
cross-coupling reactions (thus expanding the substrate scope with carbene precursors) and
carbene polymerisation (allowing the synthesis of highly functionalised stereoregular polymers
that are difficult to prepare otherwise). Recent developments in these fields in combination with
the close analogy of carbene insertion reactions with CO (and alkene) insertions open up new
possibilities for the development of interesting new reactions based on carbene insertions