Efficient allylation of 4-silyloxyquinolinium triflates and other positively charged heteroaromatic systems

The regioselective allylation of 4-silyloxyquinolinium triflates with allyltri-n-butyltin has been performed to give 2-allyl-4-silyloxy-1,2-dihydroquinolines with excellent yields. Similiar results have been obtained with 4-silyloxy-1-benzopyrylium triflates and 4-silyloxy-1-benzothiopyrylium triflates.