硫代硝酸

和氧一样，含硫化合物如硫醇，硫缩酮，硫缩醛以及硫羰基化合物在氟代试剂的作用下，碳硫键断裂，硫原子被氟取代，生成相应的氟化物。这个方法于1976年由Kollonitsch和Marburg首次报导。和氧相比，硫更容易被取代。常用的试剂包括HF/CF3OF，HF/F2，HF/Pyridine，Bu4NH2F3，Tol-IF2，SF4，FBr3，MoF6和DAST等。

硫醇被氟取代生成相应的一氟代化合物【J. Org. Chem.1976, 47, 3107】。

而硫缩酮和硫缩醛可以和HF.Py【J. Org. Chem.1986, 51, 3508.】或BrF3反应生成二氟代化合物，如果底物含有对酸敏感的基团，Bu4NH2F3是很好的替代方法。

Tol­-IF2也能在温和地的条件下高产率的取代硫缩酮【Synlett.1991, 191】。

硫羰基化合物，如硫酰氯，硫酯等经HF/Pyridine，Bu4NH2F3，MoF6或DAST处理，也生成氟代化合物【Tetrahedron. Lett. 1973, 2253.】【 J. Org. Chem., 1990, 55, 768.】。

反应实例

To a solution of thioester (1.58 g, 10 mmol) indry CH2Cl2 (20 mL) was dropped DAST in CH2Cl2(1M, 20 mL, 20 mmol) at room temperature under nitrogen atmosphere. The reaction mixture was stirred for 6 h, andthen quenched by addition of saturated NaHCO3 (30 mL). The organic layer was separated, and theaqueous phase was extracted with CH2Cl2. The combined organic layer was dried over Na2SO4,concentrated under reduced pressure. The residue was purified by column chromatography onsilica gel to give the desired product (1.32 g, 81%).

【 J. Org. Chem., 1990, 55, 768.】

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