Phase-Transfer-Catalyzed Intramolecular Hydroaryloxylation and Hydroamination of C≡C Triple Bonds: An Efficient Synthesis of Benzo[<i>b</i>]furan and 3-Methyleneisoindoline-1-one Derivatives

Phase-transfer-catalyzed intramolecular cyclization reaction of forming benzo[b]furan and 3-methyleneisoin- doline-1-one derivatives has been developed. The cyclization reaction of propargylic carbonates was also de- scribed under metal-free condition and the reaction was reported by Pd and Ni before. The reaction condi- tions and the scope of the process are examined. The catalysts are cheap and environmentally friendly and the substrates are readily available and the procedure is simple, rapid, and general. The development of C-O and C-N bond formation processes via an overall structural isomerization represents the most atom-eco- nomical approach.