Chemistry Letters, Vol.43, No.2, 181-183, 2014
Palladium-catalyzed Cycloaddition of Alkynyl Aryl Ethers to Allenes to Form a 2,3-Bismethylidene-2,3-dihydro-4H-1-benzopyran Framework
Palladium-catalyzed cycloaddition of alkynyl aryl ethers to allenes proceeds through o-C-H activation to give 2,3-dihydro-4H-1-benzopyran derivatives containing 2,3-exo-double bonds. These benzopyran derivatives further cycloadd stereoselectively to dienophiles to give condensed polycycles.