Regioselective C-H Thiocyanation of Arenes by Iron(III) Chloride Catalysis.

Aryl thiocyanates are flexible synthetic intermediates that can be used in the preparation of a diverse range of arene building blocks for medicinal chemistry. Here, we report a fast and efficient Lewis acid-catalyzed method for the regioselective thiocyanation of arenes. Iron(III) chloride was found to be an effective Lewis acid for the activation of N-thiocyanatosaccharin and the subsequent thiocyanation of a wide range of activated arenes. The procedure was applicable for the thiocyanation of biologically active compounds such as metaxalone and an estradiol derivative and was used as part of a one-pot tandem iron-catalytic process for the regioselective, dual functionalization of an arene building block.