Serendipitous Pathway to Naphtho[2,1-b]furan and Its Thioether Enabled by Triflic Acid and Thiol Mediated Reaction

We have developed a selective method for 2-phenyl naphthofuran and thio-ether derivatives using hydroxy naphthofuranone and thiols in triflic acid. Product selectivity is controlled by altering the reagent equivalents. This broad-scope, acid-mediated strategy enables diverse functionalization, overcoming regioselectivity challenges and providing a valuable tool for medicinal chemistry and organic synthesis.