Unlocking Some Si‐Centered Reactivity of a 4,4’‐Dichloro‐1,4‐di‐hydro‐1,4‐phosphasiline

Abstract

Potassium 1,4‐dihydro‐1,4‐phosphasilin‐1‐ide 1 was converted into 1,4‐dihydro‐1,4‐phosphasiline 2 via reaction with triphenylmethylchloride (Ph3CCl) to establish steric protection around the P center. Compound 2 was successfully converted to the tricyclic SiCl2 derivative 3 and, subsequently, into 4 and 5 using MeLi and MeOH, respectively. Reduction of 3 at low temperature gave transient tricyclic silylene 6 which was successfully trapped by 1,3‐butadiene to give the spiro‐silolene derivative 7. DFT studies provide insight into reduction and silylene formation.