N‐nacnac Stabilized Tetrelenes: Formation of an N,P‐Heterocyclic Germylene via C–C Bond Insertion.

The use of an amino‐functionalized β‐diketiminate ("N‐nacnac") ligand in low‐valent germanium chemistry is reported, with a view to comparison with "conventional" nacnac systems. Transmetallation of the N‐nacnac ligand from lithium allows access to a versatile chlorogermylene system, and subsequent substituent exchange processes are used to generate related hydrido‐, and phosphaketenyl‐germylenes. The latter undergoes photolytically‐induced cleavage of the P–CO bond to yield an unusual imine‐coordinated N,P‐heterocyclic germylene. On the basis of DFT calculations this transformation is proposed to occur via concerted attack by the electron‐rich carbon–carbon bond of the N‐nacnac backbone accompanying CO loss, rather than via the generation of a free phosphinidene. [ABSTRACT FROM AUTHOR]