Organocatalytic Enantioselective Friedel–Crafts Reaction of 1‐Naphthols with Isatins and an Unexpected Spontaneous Dehydration Process

Abstract

Abstract An organocatalytic enantioselective Friedel–Crafts alkylation of 1‐naphthols with isatins has been developed. The process is catalyzed by a simple cinchona alkaloid derived thiourea and gives biologically interesting, enantioenriched 3‐(naphthalen‐2‐yl)‐3‐hydroxy‐2‐oxindoles in moderate to good yields of 42–83 % and with good to high enantioselectivity of up to 94 % ee . Furthermore, an unexpected intramolecular dehydration reaction proceeds spontaneously with 4‐substituted 1‐naphthols to offer structurally different ketone oxindoles.