DAST

CAS 38078-09-0, Cat. No EN300-97056
Reagent for deoxofluorination

EnamineStore

Diethylaminosulfur trifluoride or well-known DAST is a reagent for fluorination that is still actual in organic synthesis. It is a yellow liquid that is relatively safe compared to SF₄ but requires careful working¹. DAST can convert alcohols to fluorides aldehydes, unhindered ketones to difluorides, and finally carboxylic acids to acyl fluoride, and sulfoxides to α-fluoro sulfides with high yields^1,2. In some cases, DAST can promote cationic rearrangements (Wagner-Meerwein rearrangement, pinacol rearrangement) which is important to remember. But still, the price of the reagent and easy separation of the product from byproducts of the reaction compared to more modern Ishikawa's reagent makes DAST a valuable reagent³.

Synonyms: Sulfur, (N-ethylethanaminato)trifluoro-, (T-4), ethanamine; N-ethyl-, sulfur complex; (T-4); (N-ethylethanaminato)trifluorosulfur; trifluoro(diethylamino)sulfur; (diethylamino)sulfur trifluoride; diethylaminosulfurtrifluoride