The present invention deals with the synthesis and applications of new cationic compounds being useful as metal ligands. Specifically, N-alkyl/aryl substituted pyridiniophosphines are prepared and used as ligands for transition metals. The so-obtained metal complexes and their use as catalysts in chemical synthesis is also described. It also worth mentioning that N-alkyl/aryl pyridiniophosphines can be synthesized through a short, scalable and highly modular route.