Synthesis of Heteroarene‐Fused Cyclopentadienes and Related Compounds Suitable for Metallocene Preparation

Abstract

Metallocene catalysis is widely used in transformations of unsaturated organic compounds, including the bulk industrial synthesis of polyolefins. Over the last few decades, the electronic and structural properties of their η5‐coordinated ligands have been modified by introducing electron‐donating, electron‐withdrawing, and sterically hindered substituents to obtain desirable catalytic properties for the metallocenes. An efficient way to design η5‐coordinated ligands is to exploit the annelation of heterocyclic fragments with a cyclopentadiene ring. In the present review, we summarize, systematize, and analyze synthetic approaches to heterocycle‐fused cyclopentadienes suitable for metallocene catalyst preparation.

Bimetallic complexes that merge metallocene and pincer-metal building blocks: synthesis, stereochemistry and catalytic reactivity

“…[32][33][34] For example, pincer-metal complexes have been used as excellent catalysts for a plethora of transformations in organic synthesis such as hydrogenations, dehydrogenation, cross-coupling, borylations, etc. [35][36][37][38][39][40][41][42][43][44][45][46][47][48] In view of the orthogonal properties of the metallocene and the pincer-metal platform, combined with the fact that metallocenes are well-accessible to functionalization 6,7,30,49 the question arises; "Could a merger of metallocene and pincermetal aspects lead to discovery of novel materials with dual properties"? This Perspectives explores what already has been reported and discusses the peculiar effects that have been discovered for these bimetallic species.…”