Phospholes

Abstract

Over the last decade the chemistry of phospholes has matured significantly. In this chapter, recent investigations into the structure and properties of these five-membered heterocyclic ring systems are reviewed, which highlight the extent of their aromatic character and the factors upon which this depends. Developments in the synthesis and reactivity of phospholes are described, emphasizing their use for the preparation of other phosphorus-containing heterocycles such as phosphanorbornenes and phosphinines. An overview of phospholes and phospholyl ligands as metal scaffolds in variety of catalytic applications is presented, outlining the utility of such systems in asymmetric transformations. Some of the most exciting recent developments in the uses of phospholes and related compounds are described such as the use of phosphole and P-substituted phosphole derivatives as building blocks for the preparation of readily tuned π-conjugated materials as components of optoelectronic devices, as therapeutic agents, and as metal scaffolds in a variety of catalytic applications.