Efficient syntheses of heterocycles and carbocycles by electrophilic cyclization of acetylenic aldehydes and ketones.

Highly substituted oxygen heterocycles can be prepared in good yields at room temperature by reacting o-(1-alkynyl)-substituted arene carbonyl compounds with NBS, I(2), ICl, p-O(2)NC(6)H(4)SCl, or PhSeBr and various alcohols or carbon-based nucleophiles. Naphthyl ketones and iodides are readily prepared by the reaction of 2-(1-alkynyl)arene-carboxaldehydes with I(2) and simple olefins or alkynes.