Developing the chemistry of monovalent phosphorus

Electrophilic terminal phosphinidene complexes can be seen as singlet phosphinidenes stabilized by complexation with electron withdrawing metallic centers. They allow the development of an original P(I) chemistry whose latest results are summarized. These include the description of the first stable electrophilic terminal phosphinidene complexes, new precursors for the widely used transient [RP-M(CO)5] complexes (M = Cr, Mo, W), new substituents at phosphorus, new reactions and new decomplexation techniques. Finally, a different approach is proposed for stabilizing singlet phosphinidenes by formation of adducts with nitrogen bases such as N-methylimidazole. The resulting zwitterions are potentially equivalent to singlet nucleophilic phosphinidenes. Their synthetic potential remains to be explored.