Ferric (III) chloride-promoted electrophilic thiocyanation of aromatic and heteroaromatic compounds

Abstract

Indoles, oxindoles and aromatic amino compounds undergo smooth thiocyanation with ammonium thiocyanate in the presence of anhydrous FeCl₃ in dichloromethane under mild conditions to afford the corresponding 3-indolyl and 4-aryl thiocyanates, respectively, in high yields with excellent selectivity. The use of ferric chloride makes it quite simple, more convenient and practical. This new method offers several advantages such as high conversions, cleaner reaction profiles, short reaction times, and the use of inexpensive and readily available catalyst.