Fluorinations with DAST and BAST Deoxofluor

Because DAST (diethylaminosulfur trifluoride) and BAST (bis(2-methoxyethyl) aminosulfur trifluoride commercialized as Deoxofluor) hydrolyze readily, giving HF, similar precautions must be taken as for handling hydrofluoric acid and its amine complexes [4]. Because neat DAST tends to explode if heated above 40-50 °C, safety screens are recommended if DAST is heated. For reactions or more inert substrates, requiring higher temperatures, BAST (Deoxofluor) was developed as a safer alternative, because it decomposes on heating only slowly and without detonation [11]. 

In the fluorination reactions described in Sections A.4.2 and A.4.3 BAST may be replaced by DAST with similar results. 

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