Mild and Efficient Method for α-Thiocyanation of Ketones and β-Dicarbonyl Compounds Using Bromodimethylsulfonium Bromide–Ammonium Thiocyanate

Abstract

An efficient and convenient method for α-thiocyanation of ketones and β-dicarbonyl compounds has been developed using a reagent combination of bromodimethylsulfonium bromide (BDMS) and ammonium thiocyanate in acetonitrile. The developed method is mild and gave good yield of the products at room temperature.

Keywords:

• Ammonium thiocyanate
• BDMS
• β-dicarbonyl compounds
• ketones
• α-thiocyanation

Notes

^a Reaction was performed on 5 mmol scale.

^b 1a (1 equiv): BDMS–NH₄SCN.

^c Reaction carried out using a mixture of BDMS and NH₄SCN.

^d Addition sequence is acetophenone, BDMS, and NH₄SCN.

^e NH₄SCN was added after complete consumption of 1a to form 2a.

^f By gas chromatography.

^a Isolated yield by column chromatography.

^a Reactions were carried out on 5-mmol scale at rt using 1.5 equiv of BDMS and 3.0 equiv of NH₄SCN in acetonitrile.

^b Yield by column chromatographically isolated compounds.

^c A mixture of decomposed product was obtained.