A clay-mediated eco-friendly thiocyanation of indoles and carbazoles

Indoles 1a–f and carbazoles 3a–c on treatment with ammonium thiocyanate on montmorillonite K10 clay at 80°C furnished the corresponding 3-thiocyanato derivatives 2a–f and 4a–c in good to high yields. Skatole 5 furnished the dimeric oxindole 6, which resulted from autoxidation.