Synlett 2009(12): 2035-2036  
DOI: 10.1055/s-0029-1217441
SPOTLIGHT
© Georg Thieme Verlag Stuttgart ˙ New York

Potassium Thiocyanate (KSCN): A Versatile Reagent

Soheil Sayyahi
Chemistry Department, College of Science, Chamran University, Ahvaz 61357-4-3169, Iran
e-Mail: sayyahi.soheil@gmail.com;
Further Information

Publication History

Publication Date:
03 July 2009 (online)

Introduction

Potassium thiocyanate (KSCN) is a white odorless, crystalline powder, slightly hydroscopic, and commercially available reagent. It is readily soluble in water and stable under normal temperature and pressure (mp: 173 ˚C, d = 1.89 g/cm³). Since sulfur-containing groups serve as an important auxiliary function in synthetic sequences, [¹] potassium thiocyanate is widely used as a transfer reagent for sulfur in various organic transformations. [²] The hypervalent iodine(III) in combination with potassium thio­cyanate and diphenyl diselenide promoted a multicomponent reaction for the synthesis of phenylselenyl thiocyanates and isothiocyanates from alkenes. [³] Various tosyl and ­bromo derivatives of Cbz-, Boc-, and Fmoc-protected threonine methyl esters have been subjected to nucleophilic substitution with potassium thiocyanate in acetonitrile for the synthesis of allo- and threo-3,3′-dimethylcystine derivatives. [4] This reagent is supported on silica gel and applied for thiocyanation of β-dicarbonyl compounds and the synthesis of 2-aminothiazoles. [5] Recently, potassium thiocyanate is used for the conversion of alkyl halides into alkyl thiocyanate in water under phase-transfer catalysis. [6] It is also employed for the ­synthesis of 1-aroyl-3-(substituted-2-benzothiazolyl)thioureas with antibacterial properties. [7]