Synthesis of 34-Disubstituted 2H-Benzopyrans Through C-C Bond Formation via Electrophilic Cyclization

摘要

The electrophilic cyclization of substituted propargylic aryl ethers by I2, ICl and PhSeBr produces 3,4-disubstituted 2H-benzopyrans in excellent yields. This methodology results in vinylic halides or selenides under mild reaction conditions, and tolerates a variety of functional groups, including methoxy, alcohol, aldehyde and nitro groups.