Diethylaminosulfur trifluoride

Description

Diethylaminosulfur trifluoride (DAST) is a nucleophilic fluorinating agent with wide use in organic chemistry. Deoxo-Fluor is more thermally stable alternative to DAST.

Chemical properties

Pale yellow liquid. Soluble in most non-polar organic solvents, commonly used in CH2Cl2, CHCl3 and CCl4.

What are the applications of Application

Diethylaminosulfur trifluoride (DAST) is used as a precursor to prepare 2,6-dimethoxybenzoyl fluoride and 2-thiazolines. It is a useful fluorinating agent used for a variety of compounds including alcohols, thioethers, alkenols and cyanohydrins. It also serves as a catalyst for Friedel-Crafts allylation reaction using tertiary cyclopropyl silyl ethers and in the rearrangement of homoallylic alcohols to unsaturated aldehydes. It plays an important role for gem difluorination of ketopipecolinic acids.

The Uses of Diethylaminosulfur trifluoride

Diethylaminosulfur Trifluoride is a very useful Nucleophilic fluorinating agent in chemical synthesis. It is also used as a reagent in the preparation of 2-thiazolines from (1,2)-thioam ido-alcohols.

The Uses of Diethylaminosulfur trifluoride

To a solution of the SM (3.3 g, 32.3 mmol) in DCM (100 mL) at -78 C under N2 was added DAST (13.0 mL, 96.9 mmol). The reaction mixture was stirred at -78 C for 1 h, then at RT for 1 h. The reaction mixture was then slowly poured into sat aq NaHCO3 (200 mL) at 0 C. The mixture was extracted with DCM (2 x 60 mL). The combined organics were dried (Na2SO4) and concentrated. The residue was purified by silica gel column chromatography (10:1 PE/EtOAc) to provide the product as a colorless oil. [2.2 g, 65%]