Carbene polymerization of α-diazocarbonyl compounds is a new type reaction which has been developed in recent years for the synthesis of functional polymers with an ester group at every backbone carbon atom. Carbene polymerization which differs from traditional and classic vinyl polymerizations offers a convenient and useful method to obtain polyolefins, leading to a wide range of applications in various fields. This review describes the carbene polymerization of diazo compounds (diazoacetate, diazoacetamide, α-diazoketone) in the presence of transition metals (such as copper, palladium and rhodium) and the relevant mechanisms. Besides, the copolymerizations of α-diazo compound with each other, as well as other kinds of reagents, are indicated in detail. Moreover, the carbene (co)polymerization of bisdiazo compounds are introduced. Finally, the future outlook of carbene polymerization is suggested.

Contents
1 Introduction
2 Carbene polymerizations of diazo compounds
2.1 Palladium-mediated carbene polymerizations of diazo compounds
2.2 Rhodium-mediated polymerizations of diazo compounds
2.3 Copolymerizations of diazo compounds
2.4 Carbene polymerizations of bisdiazo compounds
3 Copolymerizations of carbene polymerization with other kinds of monomers
3.1 Copolymerization of carbene with alkene
3.2 Copolymerization of carbene with alkyne
3.3 Copolymerization of carbene polymerization with cyclic monomer
4 Conclusion and outlook