The Transition Metal Chemistry of PGeP and PSnP Pincer Heavier Tetrylenes
Javier A. Cabeza, Pablo García‐Álvarez, Carlos J. Laglera‐Gándara
Abstract
This review article collects and discusses the syntheses of the currently known metal‐free heavier tetrylenes having a PEP pincer topology (E = tetrel atom) as well as their transition metal derivative chemistry. To date, only five PGeP germylenes and two PSnP stannylenes have been isolated. These compounds have been successfully synthesized by treating GeCl 2 (diox) (diox = 1,4‐dioxane), GeCl 2 (NHC) (NHC = N‐heterocyclic carbene) or SnCl 2 with two equivalents of an appropriate lithiated phosphine. Their transition metal chemistry is dominated by processes in which, in addition to the coordination of one or both phosphane groups, the E atom ends inserted into M–M or M–X (X = anionic group) bonds. Only in a few occasions a simple coordination of the tetrylene fragment (as a neutral two‐electron‐donor ligand) has been observed. The structural and bonding characteristics of the metal‐free PEP tetrylenes and of relevant examples of their transition metal derivatives are also surveyed.