Highly efficient molybdenum(II)-catalyzed intramolecular allylic alkylation of arenes

The Friedel-Crafts-type intramolecular allylic alkylation of simple arenes is performed in the presence of a catalytic amount of [Mo(II) (CO)(4)Br-2](2) (2.5 mol%). The moisture-tolerant protocol provided a mild and direct access to a large library of functionalized 4-vinyl-1,2,3,4-tetrahydronaphthalenes in high yields.