Cleavage of the Inert C(sp²)–Ar σ‑Bond of Alkenes by a Spatial Constrained Interaction with Phosphinidene

[1
+ 2] cycloaddition is a classical reaction between the electrophilic
phosphinidene and an alkene. However, a spatial constraint blocks
this well-known reaction and enables an unprecedented chemoselective
C­(sp2)–Ar σ-bond insertion of the alkene.
The theoretical calculations demonstrate that this C–C bond
cleavage is energetically feasible and thermodynamically favored through
an electrophilic rearrangement and concomitant 1,9-aryl migration
without involving any strained intermediate.