Contributions to the Chemistry of Twofold-Coordinated Group 15/14 Element Heterocycles (A Personal Account)

Abstract

Synthesis, properties, and reactivity towards metal compounds of benzo- and pyrido-anellated 1,3-azaphospholes and 1,3,2λ ² -diazaelement-2-ylidenes are described. They present heterocycles bearing a twofold-coordinated (σ ² ) group15 element in 3- or a σ ² -group14 element in 2-position. Migration of substituents between the 2- and 3-position that would make them isomers was so far not observed. Nevertheless, they are relatives with respect to stabilization of the twofold-coordinated element by inclusion into a cyclodelocalized 10π-electron system and by weak donor but notable π-acceptor properties.

Keywords:

• Catalysis
• germylenes
• hybrid ligands
• low coordination
• metal complexes
• phosphorus heterocycles

Acknowledgments

Dedicated to Professor Marian Mikołajczyk, CBMiM PAN in Łódź, Poland, on the occasion of his 70th birthday.

We thank the Deutsche Forschungsgemeinschaft (DFG) and the Deutsche Akademische Austauschdienst (DAAD) for the support of this research and scholarships for B.R. (DFG), M.S.S.A. and F.U. (DAAD).