Eszter Baráth

1 Introduction The continuous depletion of fossil resources, such as crude oil and natural gas [1, 2], necessitates the development of new strategies to meet global fuel and chemical demands. The transition from fossil, nonrenewable, resources to bio-based, potentially recyclable, chemical feedstocks is essential for ensuring a more sustainable future and for decreasing CO2 emissions [3].

Phosphorus compounds usually occur in the (+3)-oxidation state with two nonbonding electrons, rendering phosphanes of the type PR3 ubiquitous ligands in coordination chemistry. Phosphanes are also known to coordinate phosphinidenes (R–P), (1) phosphorus species in the (+1)-oxidation state, giving phosphanylidene phosphoranes of the general form R–P(−)–P(+)R3, which have been known for nearly 60 years.

Phosphorus compounds usually occur in the (+3)-oxidation state with two nonbonding electrons, rendering phosphanes of the type PR3 ubiquitous ligands in coordination chemistry. Phosphanes are also known to coordinate phosphinidenes (R–P), (1) phosphorus species in the (+1)-oxidation state, giving phosphanylidene phosphoranes of the general form R–P(−)–P(+)R3, which have been known for nearly 60 years.