Chain end functionalized polyolefins(Cef-POs) are of great importance in macromolecular design and polyolefin modifications. By utilizing self-induced chain transfer reactions (to β -H, e.g.) or using chain transfer agents such as borane, phosphine and styrene (and its derivatives)/H₂ in olefin coordination polymerization, unsaturated bond and reactive group terminated polyolefins can be obtained, respectively. Successive chemical modification of chain-end group results in various Cef-POs. Given the status of "one polymer chain per catalyst" in living coordination polymerization of olefin, Cef-POs can also be obtained by end-capping living chains and/or applying functionalized living catalysts. The problem of low catalyst efficiency encountered in living coordination polymerization can be well solved by coordinative chain transfer polymerization (CCTP), a process involving rapid and reversible chain transfer reactions between the catalyst (active species) and the chain transfer agent (usually in the form of a main group metal alkyl). CCTP generates polyolefin capped by carbon-metal bond, which is highly reactive and can be modified into versatile terminal groups. In addition, living polymerization of Ylides, living anionic polymerization of butadiene and ring-opening metathesis polymerization of cycloolefine are alternative approaches to synthesize (analogues of) Cef-PEs. The applications of Cef-POs, featured by transformation reaction from metallocene to other polymerization (living anionic polymerization, "controlled/living" radical polymerization, ring-opening polymerization, etc.) and combination with click chemistry, include two main aspects: polymer modification and synthesis of topological polymer.

Contents
1 Introduction
2 Synthesis of Cef-PO via chain transfer reaction
2.1 Without CTA: synthesis and modification of chain end unsaturated PO
2.2 Using one CTA: in situ polyolefin chain end functionalization with heteroatoms
2.3 Using two CTA: consecutive chain transfer reactions
3 Synthesis of cef-PO via living polymerization
3.1 Living anionic polymerization
3.2 Living coordination polymerization
3.3 Living polymerization of Ylides
4 Synthesis of Cef-PO via CCTP
4.1 Ethylene
4.2 Propylene
5 Conclusion and outlook