Single‐component Catalysts for Vinyl‐addition Polymerization of Norbornene and its Derivatives

Vinyl‐addition polynorbornenes are versatile templates for the targeted design of high‐performance materials for various applications, such as membrane gas separation, micro‐ and optoelectronics, fuel cells, sensors, catalyst supports, etc. The cornerstone of the syntheses of these compounds is the choice of a catalyst for polymerization. Considering valuable developments in the field of catalysts for vinyl‐addition polymerization (VAP) summarized in previously published reviews, mention should be made that the research efforts were largely focused on two‐ and three‐component catalytic systems that suffer from the need to use a cocatalyst. The aim of this review is to highlight the advances in the design and development of single‐component catalysts for the VAP of norbornenes. Such catalysts are categorized into two main groups, viz., neutral and cationic catalysts. The catalyst structure, the catalytic activity, and the molecular weight characteristics of polymers produced on these catalysts are considered in detail. We believe this article can serve as a guide for developing future catalysts to gain access to new functional materials.