Regioselective Thiocyanation of Aromatic and Heteroaromatic Compounds Using [2-(Sulfooxy)ethyl]sulfamic Acid as an Efficient, Recyclable Organocatalyst and Novel Difunctional Brønsted Acid

Table 4

Comparison of the thiocyanation of indole using the reported catalysts versus SESA.

Entry	System	Time (min)	Yield % [ref.]
1	SESA	10	97 [this work]
2	I2/MeOH	50	85 [27]
3	DDQ/MeOH	50	94 [41]
4	DEAD/MeCN	45	85 [28]
	Mn(OAc)3/HOAc	2 (h)	83 [11]
5	K10 clay/MeOH, 80°C	2 (h)	85 [26]
6	Citric acid/H2O2/H2O	20	91 [35]