硫代硝酸

和氧一樣，含硫化合物如硫醇，硫縮酮，硫縮醛以及硫羰基化合物在氟代試劑的作用下，碳硫鍵斷裂，硫原子被氟取代，生成相應(yīng)的氟化物。這個方法于1976年由Kollonitsch和Marburg首次報導(dǎo)。和氧相比，硫更容易被取代。常用的試劑包括HF/CF3OF，HF/F2，HF/Pyridine，Bu4NH2F3，Tol-IF2，SF4，F(xiàn)Br3，MoF6和DAST等。

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

而硫縮酮和硫縮醛可以和HF.Py【J. Org. Chem.1986, 51, 3508.】或BrF3反應(yīng)生成二氟代化合物，如果底物含有對酸敏感的基團，Bu4NH2F3是很好的替代方法。

Tol--IF2也能在溫和地的條件下高產(chǎn)率的取代硫縮酮【Synlett.1991, 191】。

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

反應(yīng)實例

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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