(η³‑α-Silabenzyl)tungsten Complexes: An Isolable Intermediate for Interconversion between a Silylene Complex and a Silyl Complex through 1,2-Aryl Migration

η³-α-Silabenzyl complexes Cp*W­(CO)₂{η³(<i>Si,C,C</i>)-Si­(<i>p</i>-Tol)₂R} (<b>1a</b>, R = Me; <b>1b</b>, R = <i>p</i>-Tol; Cp* = η⁵-C₅Me₅, <i>p</i>-Tol = <i>p</i>-tolyl), the first silicon analogues of η³-benzyl complexes, were synthesized by abstraction of DMAP (4-(dimethylamino)­pyridine) with BPh₃ either from (aryl)­(DMAP·silylene)tungsten complexes <b>2a</b>,<b>b</b> at room temperature or from (arylsilyl)­(DMAP)­tungsten complexes <b>3a</b>,<b>b</b> under irradiation. Complex <b>1</b> was demonstrated to be a key intermediate for the interconversion between <b>2</b> and <b>3</b> and to serve as a synthetic equivalent for both base-free silylene complexes and coordinatively unsaturated silyl complexes