Synthesis of naphthalenes and 2-naphthols by the electrophilic cyclization of alkynes

摘要

A wide variety of substituted naphthalenes are readily prepared regioselectively under mild reaction conditions by the 6-endo-dig electrophilic cyclization of appropriate arene-containing propargylic alcohols by ICl, I-2, Br-2, NBS, and PhSeBr. 3-Iodo-2-naphthols have also been prepared in excellent yields by the cyclization of analogous 1-aryl-3-alkyn-2-ones. This methodology readily accommodates various functional groups and has been successfully extended to the synthesis of substituted carbazoles and dibenzothiophenes.