P–C reductive elimination in Ru(<scp>ii</scp>) complexes to convert triarylphosphine ligands into five- or six-membered phosphacycles

Rare examples of P-C reductive elimination in ruthenium complexes to generate phosphonium salts are presented. Triarylphosphines are converted into benzophospholium or phosphaphenalenium ligands via cyclometalation and 1,2-insertion of an alkyne followed by P-C reductive elimination. The intermediate in each step was successfully characterized using NMR and X-ray diffraction studies.