Annelation of Carbene Ligands by λ³‐Phosphaalkynes, an Entry to Functionalized Phosphaarenes

Abstract

Phosphaarenes from Phosphaalkynes by reaction with carbene(carbonyl) complexes [Eq. (a)]. This reaction principle was first realized in the case of two chromium complexes (R = Me, Et). 3-Phosphaphenanthrene was liberated almost quantitatively from the product with R = Et on reaction with CO, thus allowing recovery of the Cr(CO)6 required for the synthesis of the carbene complex.