Phosphonium salts and P-ylides

The present review collects and describes the literature on preparation, characterisation and applications of phosphonium salts and ylides, published between January and December 2021. The large number of reviewed references highlights the importance of P-based derivatives in synthetic and non-synthetic applications. For the Reader’s convenience, topics are organized to offer an introductory survey on the methods of preparation and characterisation of each type of compound, followed by an analysis of applicative and curiosity driven research. Recent advances on synthesis and applications of phosphonium-based ionic liquids (PILs) are summarised in a dedicated section, highlighting, in particular, the ever-increasing number extraction and energy storage applications reported for these P-based ionic liquids.