Open and cyclic double silylated phosphorus and boron compounds - chasing trisilylboranes

The amount of publications containing silylboranes is quite small, although first substances containing silicon boron bonds were reported in the 1960s. In the last decade, the interest in silylated boron compounds increased due to the various catalytic possibilities in metalorganic chemistry.
Phosphacyclopentasilanes are, as well as the boron alternatives, still sparsely examined in metalorganic chemistry. In 1965 ring opening reactions of octaphenylcyclotetrasilanes via reaction of the dilithiumsalt Li(SiPh2)4Li with dichlorophanylphoshane led to novel nonaphenylphosphacyclosilane.
In 2004 a reaction pathway for the reaction of tris(trimethylsilyl)silyl potassium with piperidinodichloroboranes and dichlorophaophanes was successful in the formation of bora- and phosphacyclopentasilanes.
Our research group is especially interested in the reactivity of the cyclic silylated phosphorus compounds, which could lead to a novel way of stabilizing heavy metal systems such as diphosphatetrylenes.
Double silylated boron compounds might be promising intermediates in the synthesis of trisilylated boron compounds, which are still quite unexplored in organosilicon chemistry. DFT calculations were used to predict stabilities and spectroscopic properties of intermediates and potential products.