Heavier group 13/15 multiple bonds have been under investigation since the late 80s and to date, several examples have been published, which shows the obsoleteness of the so-called double bond rule. Especially in the last few years, more and more group 13/15 multiple bonds became synthetically feasible and their application in terms of small molecule activation has been demonstrated. Our group has recently shown that the combination of the pnictinidene precursor ^DipTer–Pn(PMe₃) (Pn = P, As) in combination with Al(I) synthons afforded the first examples of phospha- and arsaalumenes as isolable and thermally robust compounds. This feature article is intended to show the recent developments in the field, to outline early synthetic approaches and to discuss strategies to unlock the synthetic potential of these elusive chemical bonds.

Phospha–Wittig reagents of the type RPPMe₃ can be considered as phosphine-stabilized phosphinidenes and were shown to react with NHCs and NHOs to afford NHC phosphinidene adducts or P-substituted NHOs, respectively.

Using titanocene synthon [Cp ₂ Ti(Me ₃ SiC ₂ SiMe ₃ )] the selective conversion of aryl-substituted triphosphiranes P ₃ Ar ₃ into Cp ₂ TiP ₂ Ar ₂ complexes was achieved.