Boron Trifluoride-Mediated Domino Dehydration/Electrophilic Cyclization of Silylalkynols Leading to 2,3-Fused Tricyclic Benzofulvenes.

A BF-mediated domino dehydration/electrophilic cyclization of silylalkynols to form 2,3-fused tricyclic benzofulvenes was achieved. In the latter step, in situ generated BF·OH enables the electrophilic activation of alkynes. The predominant -selectivity of the reaction is also discussed.