Transition-Metal-Free One-Pot Synthesis of Naphthoquinonefuran Derivatives Through Sequential Nucleophilic Substitution-Nucleophilic Addition Reaction.

A transition-metal-free route for tandem one-pot synthesis of naphthoquinonefuran derivatives from 2-hydroxynaphthoquinones has been developed. The sequentially accomplished process comprises an intermolecular alkynylation of sp-carbon at the 3 position of 2-hydroxynaphthoquinones with arylethynyl bromides, followed by a base-promoted intramolecular nucleophilic annulation reaction. A broad range of functional groups is compatible with this reaction, and diverse naphtho[2,3-]furan-4,9-diones can be obtained with good yields and excellent regioselectivity.