## 2 Experimental Section
### General Procedure for the Preparation of Selectively Fluorinated Ketones [10,13]
NMR: \({}^{1}\)H: \(\delta\) 3.73 (2H, s), 7.29 (2H, m), 7.60 (2H, m), 14.19 (1H, bs), \({}^{13}\)C: \(\delta\) 40.9, 111.5, 120.4 (CF\({}_{3}\), q, \({}^{1}\)J\({}_{\rm C-F}\) = 277 Hz), 122.9, 123.0, 124.9, 127.7, 128.1, 128.8, 129.6, 154.5 (C-CF\({}_{3}\), q, \({}^{2}\)J\({}_{\rm C-F}\) = 37 Hz), 203.0. \({}^{19}\)F: \(-\)68.59 (s, 3F). Analysis calcd for C\({}_{11}\)H\({}_{7}\)F\({}_{3}\)O\({}_{2}\): C, 57.90, H, 3.09. Found: C, 58.04, H, 3.02. 1,3-ditrifluoroacetyl-2-indanone (**2c**). To 30 mL dry Et\({}_{2}\)O in a round bottom flask equipped with a magnetic stirrer is added sodium methoxide (0.449 g, 8.32 mmol) all at once. Then, trifluoromethyl ethyl acetate (0.903 mL, 7.57 mmol) is added dropwise slowly while stirring. After 5 minutes, 2-indanone (1.00 g, 7.57 mmol) dissolved in 20 mL dry Et\({}_{2}\)O is added dropwise and stirred overnight at room temperature under a calcium chloride drying tube. After 24 h, another equivalent of trifluoromethyl ethyl acetate is added dropwise and stirred overnight at room temperature under a calcium chloride drying tube. The reaction mixture is acidified with 30 mL 3\(M\) sulfuric acid. The organic layer was separated, washed with deionized water, and the organic layer dried over Na\({}_{2}\)SO\({}_{4}\). The solvent was evaporated under reduced pressure, providing a yellow solid, which when recrystallized, yielded yellow crystals (cyclohexane), in 42% yield, m.p. 111-113 \({}^{\circ}\)C. NMR: \({}^{1}\)H: \(\delta\) 7.34 (2H, m), 7.65 (2H, m), 13.50 (2H, bs). \({}^{13}\)C: \(\delta\) 111.5, 118.4 (CF\({}_{3}\), q, \({}^{1}\)J\({}_{\rm C-F}\) = 273 Hz), 119.6, 122.9, 126.7, 128.4, 128.9, 130.2, 168.5 (C-CF\({}_{3}\), q, \({}^{2}\)J\({}_{\rm C-F}\) = 35 Hz), 177.0. \({}^{19}\)F: \(-\)68.53 (s, 3F). HRMS (ESI+) calcd for C\({}_{13}\)H\({}_{6}\)F\({}_{0}\)O\({}_{3}\): 324.02211, found: 324.02158. 3-trifluoroacetyl-2-tetralone (**3b**) and 1-trifluoroacetyl-2-tetralone (**3c**). These compounds were obtained as a 4:3 mixture of **3b**:**3c**. Radial chromatography (100% CH\({}_{2}\)Cl\({}_{2}\)-50/50 CH\({}_{2}\)Cl\({}_{2}\)/MeOH) afforded two product fractions. Fraction 1: **3b** as orange crystals (hexane), in 40% yield, m.p. 123-126 \({}^{\circ}\)C. NMR: \({}^{1}\)H: \(\delta\), 3.76 (2H, s), 3.81 (2H, s), 7.25-8.05 (4H, m), 15.01 (1H, bs). \({}^{13}\)C: \(\delta\) 27.8, 38.3, 103.7, 117.5 (CF\({}_{3}\), q, \({}^{1}\)J\({}_{\rm C-F}\) = 281 Hz), 127.1, 127.3, 127.8, 127.9, 130.5, 133.4, 157.3, 174.8 (C-CF\({}_{3}\), q, \({}^{2}\)J\({}_{\rm C-F}\) = 35 Hz), 191.0. \({}^{19}\)F (C\({}_{6}\)F\({}_{6}\) ext. std. ): \(\delta\)\(-\)70.62 (s, 3F). HRMS (ESI+) calcd for C\({}_{12}\)H\({}_{9}\)F\({}_{3}\)O\({}_{2}\): 242.04470, found: 242.04436. Fraction 2: **3c** (30%) as an orange solid, m.p. 88-91 \({}^{\circ}\)C. **3c**: NMR: \({}^{1}\)H: \(\delta\) 2.72 (2H, t, \({}^{2}\)J = 1.9 Hz), 3.01 (2H, t, \({}^{2}\)J = 1.9 Hz), 7.25 (4H, m), 14.98 (1H, bs). \({}^{13}\)C: \(\delta\) 25.0, 30.3, 102.9, 118.6 (CF\({}_{3}\), q, \({}^{1}\)J\({}_{\rm C-F}\) = 282 Hz), 126.6, 126.9, 127.3, 128.1, 130.2, 133.8, 158.1, 175.4 (C-CF\({}_{3}\), q, \({}^{2}\)J\({}_{\rm C-F}\) = 35 Hz), 189.1. \({}^{19}\)F (C\({}_{6}\)F\({}_{6}\) ext. std. ): \(\delta\)\(-\)67.70 (s, 3F). HRMS (ESI+) calcd for C\({}_{12}\)H\({}_{9}\)F\({}_{3}\)O\({}_{2}\): 242.04470, found: 242.04442. 3-trifluoroacetyl-2-naphthol (**3d**). A round bottom flask equipped with a magnetic stirrer containing 30 mL dry Et\({}_{2}\)O is charged with 1 equivalent NaOCH\({}_{3}\). Then, 1 equivalent ethyl trifluoroacetate is added dropwise slowly and stirred for 15 min. To this solution is added a 4:3 mixture of compounds **3b**:**3c** dissolved in 20 mL Et\({}_{2}\)O. The reaction mixture is stirred overnight at room temperature under a calcium chloride drying tube. The solvent is removed under reduced pressure while heating at 60 \({}^{\circ}\)C for 20 min. The solid residue is acidified with 30 mL 3\(M\) sulfuric acid and extracted with 3-15 mL portions of Et\({}_{2}\)O.