Synthesis and Applications of 9/9,9‐Substituted Fluorene Derivatives

Fluorene derivatives have obtained broad interest in organic synthesis, materials chemistry, and pharmaceutical fields due to their unique structure, physical, chemical and photoelectric properties. Moreover, the bare fluorene molecule has a variety of reactive sites that provides the transformations to synthesize various functionalized intermediates, polymers and macrocycles. Recently, C‐C bond formation is one of useful tool in fluorene molecule modifications due to the low toxicity and high efficiency. This review covers the synthesis of various fluorene‐based small molecules, fluorene‐based polymers, fluorene‐based conjugated materials and fluorene‐based nanogrids via the C‐C bond formation at the 9‐position of fluorene derivatives. Transition‐metal catalysis and metal‐free methods to synthesize different fluorene derivatives are highlighted.