上海
Prakash 试剂（TMSCF3）是非常一种重要的三氟甲基化试剂，可以对羰基化合物进行亲核取代。此方法是在1984 年由Ruppert 首先报道，随后Prakash 对其应用做了大量的工作，这是从羰基化合物合成三氟甲基化合物最便捷的方法，反应条件温和，操作方便，产率较高，在有机合成中的应用也很广泛。
反应加入少量氟化物（如TBAF, CsF 等）催化，TMSCF3 对羰基的缺电子碳进行亲核取代，最后生成三氟甲基取代的化合物，如果是酯作为底物，水解后则生成三氟甲基酮。
反应实例
(Wiedemann, J; Heiner, T; Prakash, G, K, S. Angew. Chem. Int. Ed. 1998, 37, 820)
To the solution of methyl benzoate (1.36 g, 10 mmol) and TMSCF3 (1.78g, 12.5 mmol) in dry toluene (20 mL) was added the initiator anhydrous tetrabutylammonium fluoride (TBAF; 2.5 mol% in THF) -78oC, and the reaction mixture was then allowed to warm slowly to room temperature, stirred for 18 h. The resulting mixture was treated with 2M hydrochloric acid (5 mL), extracted with EA, washed with water and brine, the organic phase was concentrated under reduced pressure. The residue was purified by column chromatography on silica gel to give 1,1,1-trifluoroacetophenone (1.65 g, 95%).
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