Sr. Angle et Jp. Boyce, FORMAL [3-CYCLOADDITIONS AND [3+2]-CYCLOADDITIONS OF ALLYLSILANES WITH BENZYLIC CATIONS(3]), Tetrahedron letters, 35(35), 1994, pp. 6461-6464
Allylsilanes serve as three-carbon dipole equivalents for the formatio
n of tetrahydronaphthalenes via Lewis-acid promoted formal [3+3]-cyclo
additions with benzylic cations. A competing [3+2]-pathway resulted in
the formation of dihydro(1H)indenes. Both quinone methides and benzyl
ic alcohols were used as precursors to the benzylic cations.