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N,N-二三氟甲磺酰基-5-氯-2-吡啶或N,N-二三氟甲磺酰基苯胺，此类芳胺的二三氟甲磺被称为Comins三氟甲磺酸化试剂。其可以将酮类，酯，硫代酸酯转化为相应的三氟甲磺酸烯酯。由于此试剂的活性较高，条件温和，因此广泛应用于。

【Comins DL， Tet Lett， 1992， 33， 6299】

试剂的制备

N-(2-Pyril)triflimide ). A 2-L, two-necked, round-bottomed flask equipped with a meanical stirrer (Note 1) and a rubber septum is charged with 2-aminopyridine (19.859 g, 0.1 mol) (Note 2) and pyridine (35.04 g, 35.88 mL, 0.443 mol) (Note 3) in 800 mL dichloromethane (CH2Cl2) (Note 4) under an argon atmosere. The mixture is cooled to −78°C and a solution of triflic anhydride (125 g, 74.54 mL, 0.443 mol) (Note 5) in 150 mL of CH2Cl2 is added dropwise via a cannula over 3.5 hr with vigorous stirring. After the solution is stirred for 2 hr at −78°C, the cooling bath is removed and stirring is continued at room temperature for 19 hr. The reaction mixture is quenched with 50 mL of cold water and the layers are separated. The aqueous layer is extracted with CH2Cl2 (4 × 50 mL). The combined organic extracts are washed with cold aqueous 10% sodium hydroxide (1 × 150 mL), cold water (1 × 100 mL), brine (1 × 100 mL) and dried over magnesium sulfate. After filtration, the solvent is removed under vacuum to give 69 g of the crude product. After Kugelrohr distillation (Note 6), 61 g (81%) of pure N-(2-pyridyl)triflimide (bp 85–100°C/0.25 mm, mp 41–42°C) (Note 7) is obtained as a white solid.

【Joseph SP, Org Synth, 1997, 74, 77】

反应实例

【Joseph SP, Org Synth, 1997, 74, 77】

Enol triflate (5). Under N2 at 78 C, b-thio-tyrolactone 4 (0.17 mL, 2 mmol) in THF (5 mL) was treated with KHMDS (4.4 mL, solution of 0.5 M in PhMe). After 1 h stirring, 3 (780 mg, 2 mmol) in THF (2 mL) was added. After 3 h at 78 C, quenching (H2O), extraction (Et2O), evaporation and chromatography (Al2O3 neutral) gave 342 mg of 5 (73%).

【O’Neil IA, Synlett, 1995, 151】

【Nicolaou KC, J Am Chem Soc, 2009, 131, 10587】

To a solution of compound 13 (15 mg, 0.052 mmol) in dry THF (5 mL) was added KHMDS (115 μL, 0.057 mmol) at -78 o C, and the mixture was stirred at the same temperature for 30 min. To this solution was added Comins (N-(5-chloro-2-pyridyl) triflimide) (23 mg, 0.057 mmol) in dry THF (2 mL) -78 o C, and the mixture was then stirred at the same temperature for al 3 h. The reaction was quenched by addition of a saturated solution of NH4Cl (5 mL), and the mixture was extracted with Et2O (3 x 10 mL). The combined extracts were dried over sodium sulfate. The solvent was removed in vacuo and the residue was purified by a flash chromatography on silica gel (hexane/ethyl acetate，10/1) to give 13a (21 mg) in 92% yield as white solid. It is worthwhile to mention that excessive KHMDS will lead to lower yielding.

【Yang Z, J Am Chem Soc, 2010, 132, 13608】

Enol triflate (–)-67: To a solution of ketone (–)-65 (1.80 g, 5.48 mmol) in THF (100 mL) at –78 °C was added KHMDS (1.5 equiv, 0.5 M in PhMe, 16.4 mL, 8.22 mmol). The reaction mixture was stirred 10 min before a solution of Commins reagent (1.5 equiv, 3.22 g, 8.22 mmol) in THF(20 mL) was added dropwise. The resulting mixture was warmed to –40 °C then quenched with saturated aqueous NH4Cl solution (50 iphasic mixture was extracted with Et2O (50 mL TfO (MgSO4), and concentrated under reduced ssure. The crude residue was purified by flash column chromatography (silica, Et2O/hexanes, 1 → 4%) to furnish enol triflate (–)-67 (2.43 g, 5.15 mmol, 94%) as a colorless oil.

【Nicolaou KC, J Am Chem Soc, 2010, 132, 7138】

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