Reversible Dimerization of Phosphine‐Stabilized Silylenes by Silylene Insertion into Si^II–H and Si^II–Cl σ‐Bonds at Room Temperature

Abstract

Contrary to the classical silylene dimerization leading to a disilene structure, phosphine stabilized hydro- and chloro-silylenes (2 a,b) undergo an unique dimerization via silylene insertion into SiX σ-bonds (X=H, Cl), which is reversible at room temperature. DFT calculations indicate that the insertion reaction proceeds in one step in a concerted manner.

The Road Travelled: After Main‐Group Elements as Transition Metals

“…Extension of this work towards other reversible M−C insertions was found to be successful with dimethylzinc and stannylene . Currently examples of reversible tetrylene reactions are limited to a handful of reports,,, thus showing great potential for this class of compounds towards catalysis, particularly Power's recent example of reversible elimination of H 2 from a stannylene …”

“…Whilst this reversibility has been shown in some cases with small molecules, extension to H−E (E=B, Si, P etc) bond activation provides potential for hydroelementation catalysis and isolation of value added products. Within this field, Baceiredo and Kato reported reversible silylene insertion reactions into Si−H and P−H σ‐bonds at room temperature (Scheme a) . The silylene ( 60 ) and the H−E activation product ( 61 ) are in equilibrium, with the position of the equilibrium determined by the temperature, steric bulk of the silylene and bulkiness of the substrate.…”

A Fully Phosphane‐Substituted Disilene

“…Very recently Bacereido, Kato, and co‐workers reported the dimerization of heteroleptic, intramolecularly base‐stabilized amino‐chlorosilylenes and amino‐hydrosilylenes by insertion of one silylene fragment into the Si−X bond of another to give compounds G . To date, there have been no reports of disilenes substituted by three or more group 15–17 atoms, which are isolable in the solid state.…”

A Fully Phosphane‐Substituted Disilene

“…[10] Similarly,Müller, Kira, Apeloig, and coworkers have proposed ad ynamic equilibrium between the diaminosilylene (iPr 2 N) 2 SiD and its disilene dimer, based on variable-temperature UV/Vis spectroscopy;a lthough this latter disilene has not been isolated and these studies suggest that the disilene itself is am inor component over the temperature range measured. Izod insertion of one silylene fragment into the SiÀXb ond of another to give compounds G. [13] To date,there have been no reports of disilenes substituted by three or more group 15-17 atoms,which are isolable in the solid state. Izod insertion of one silylene fragment into the SiÀXb ond of another to give compounds G. [13] To date,there have been no reports of disilenes substituted by three or more group 15-17 atoms,which are isolable in the solid state.…”

“…[11] Very recently Bacereido,K ato,a nd co-workers reported the dimerization of heteroleptic, intramolecularly base-stabilized amino-chlorosilylenes and amino-hydrosilylenes by [*] Dr.K . Izod insertion of one silylene fragment into the SiÀXb ond of another to give compounds G. [13] To date,there have been no reports of disilenes substituted by three or more group 15-17 atoms,which are isolable in the solid state.…”