Regioselective Synthesis of Substituted Naphthalenes:  A Novel de Novo Approach Based on a Metal-Free Protocol for Stepwise Cycloaddition of o-Alkynylbenzaldehyde Derivatives with Either Alkynes or Alkenes

<UFIGR ID="ol035691tn00002">Iodonium ions, o-alkynyl-substituted carbonyl compounds, and alkynes react to give 1-iodonaphthalene derivatives featuring interesting substitution patterns. The reaction with alkenes instead of acetylenes affords related naphthyl ketone derivatives. These two metal-free processes are conducted at room temperature and furnish products in a regioselective manner.