Supporting Information for

Supporting Information for A ovel Synthesis of luorinated Pyrazoles via Gold(I)-Catalyzed Tandem Aminofluorination of Alkynes in the Presence of Selectfluor Jianqiang Qian, Yunkui Liu,* Jie Zhu, Bo Jiang, and Zhenyuan Xu* State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology, Hangzhou 310014, People s Repubilc of China Email: ykuiliu@zjut.edu.cn; greensyn@zjut.edu.cn Contents General Typical procedure for synthesis of 2 Experimental procedure for synthesis of 2 a Optimization of reaction conditions The change situation of the yields of 2a and 2'a during the S2 S2 S2 S3 5 S6 reaction time Characterization of all products References S6 S15 S15 1 H, 13 C, and 19 MR spectra of all products S16 S88 S1

General Unless otherwise stated, all reagents were purchased from commercial suppliers and used without purifications. All experiments were carried out under a nitrogen atmosphere. All solvents for reactions were dried and distilled prior to use according to standard methods. Melting points are uncorrected. The 1 H and 13 C MR spectra were recorded on a Bruker AVACE III 500 at 25 C in CDCl 3 at 500 MHz, 125 MHz, respectively, with TMS as internal standard. 19 MR were recorded on a Varian Inova 400 at 25 C in CDCl 3 at 376 MHz, with C 3 COOH as external standard. Chemical shifts ( ) are expressed in ppm and coupling constants J are given in Hz. The IR spectra were recorded on an T-IR spectrometer. GC-MS experiments were performed with an Agilent 6890 GC system equipped with a 5973 mass-selective detector with EI source, high resolution mass spectra (HRMS) were obtained on a TO MS instrument with EI source. The starting material 1 were synthesized according to reported literatures. 1,2 Typical experimental procedure for synthesis of fluorinated pyrazole 2 1 (0.2 mmol) was added into a solution of Selectfluor (141.7 mg, 0.4 mmol, 2 equiv), ahco 3 (33.6 mg, 0.4 mmol, 2 equiv) and 3 PAuTf 2 (3.7 mg, 0.005 mmol) in MeC (2 ml) under 2. Then the reaction mixture was stirred at room temperature for 2.0 h. Upon completion, the resulting mixture was diluted with CH 2 Cl 2 (10 ml) and filtered through Celite. After evaporation of the solvent under vacuum, the residue was purified by column chromatography on silica gel (100-200 mesh) using petroleum ether-etoac (10:1) as eluent to give pure 2. Experimental procedure for synthesis of 2 a 1a (0.2 mmol) was added into a solution of 3 PAuTf 2 (3.7 mg, 0.005 mmol) in MeC (2 ml) under 2. Then the reaction mixture was stirred at room temperature for 2.0 h. Upon completion, the resulting mixture was diluted with CH 2 Cl 2 (10 ml) and filtered through Celite. After evaporation of the solvent under vacuum, the residue was purified by column chromatography on silica gel (100-200 mesh) using petroleum ether-etoac (10:1) as eluent to give pure 2 a in 92 % yield. S2

Optimization of Reaction Conditions Table S1. Screening with different bases a H 3 PAuTf 2 (2.5 mol %) Selectfluor (2 equiv) base, MeC, rt, 2.0 h H 1a 2a 2'a entry base 2a/2'a b yield (%, 2a) c 1 none 1.2:1 48 2 K 2 CO 3 1.1:1 44 3 Cs 2 CO 3 1:2.3 21 4 CH 3 COOa 4.0:1 34 5 a 2 CO 3 6.1:1 72 6 ahco 3 6.2:1 81 7 ahco 3 (1.2 equiv) 3.1:1 68 8 ahco 3 (3.0 equiv) 4.0:1 74 9 ahco 3, Selectfluor (3.0 equiv) 2.6:1 56 10 ahco 3, Selectfluor (1.2 equiv) 1:1.1 43 11 H 4 HCO 3 5.8:1 68 12 K 1.9:1 62 13 LiOH 2.3:1 48 14 KOH 1:1.8 32 15 t-buok 1:8.1 9 16 Et 3 _ d _ d 17 DMAP _ d _ d 18 DABCO _ d _ d a Reactions carried out with 1a (0.2 mmol), Selectfluor (2 equiv), Base (2 equiv) and 3 PAuTf 2 (2.5 mol %) in MeC (2 ml) at rt for 2 h. b Determined by GC. c Isolated yields. d Only a small amount of 2'a was detected. S3

Table S2. Screening with different solvents a H 3 PAuTf 2 (2.5 mol %) Selectfluor (2 equiv) solvent, rt, 2.0 h H 1a 2a 2'a entry solvent 2a/2'a b Yield (%, 2a) c 1 MeO 2 1:5.1 13 2 TH _ d _ d 3 MeC 6.2:1 81 4 MeC/H 2 O = 20:1 2.1:1 54 5 CH 2 Cl 2 1:20 4 6 1,4-Dioxane _ d _ d 7 Pyridine 1:9 6 8 EtOH _ d _ d 9 DM _ d _ d 10 MeC/H 2 O = 20:1, no base _ e trace a Reactions carried out with 1a (0.2 mmol), Selectfluor (2 equiv), 3 PAuTf 2 (2.5 mol %) and ahco 3 (2 equiv) in solvent (2 ml) at rt for 2 h. b Determined by GC. c Isolated yields. d Only a large quantity of 2'a was detected. e Only 2'a was isolated in 72% yield. S4

Table S3. Screening with different catalysts a H catalyst (2.5 mol %) Selectfluor (2 equiv) ahco 3 (2 equiv), MeC rt, 2.0 h H 1a 2a 2'a entry catalyst 2a/2'a b yield (%, 2a) c 1 AuCl 1:1.2 12 2 3 PAuCl 5.3:1 76 3 AuCl 3 1:1.6 8 4 AuCl/AgOTf 1.8:1 42 5 3 PAuCl/AgOTf 3.8:1 55 6 AuCl 3 /3AgOTf 1.6:1 42 7 AuCl 3 /3AgTf 2 4.7:1 46 8 AuCl/AgTf 2 3.1:1 33 9 3 PAuTf 2 6.2:1 81 10 3 PAuCl /AgTf 2 6.2:1 81 11 3 PAuTf 2, (C 6 H 5 SO 2 ) 2 (2.0 equiv) 1:2.3 29 12 3 PAuTf 2 6.1:1 79 d 13 IMesAuTf 2 3.6:1 29 14 3 PAuCl/AgSb 6 1:1.3 39 15 3 PAuCl/Ag 5.9:1 61 16 3 PAuCl/AgC 4.1:1 36 17 3 PAuCl/AgO 2 1.9:1 44 18 AgTf 2 1.5:1 22 19 PdCl 2 1.1:1 8 20 ecl 3 2.5:1 9 21 CuI 1.6:1 15 22 none _ e _ e a Reactions carried out with 1a (0.2 mmol), Selectfluor (2 equiv), ahco 3 (2 equiv) and catalyst (2.5 mol %) in MeC (2 ml) at rt for 2 h. b Determined by GC. c Isolated yield. d Reaction temperature at 40 o C. e Both 2a and 2'a were not detected. S5

Table S4. The change situation of the yields of 2a and 2'a during the reaction time Time(h) t 0 0.25 0.50 1.00 1.50 2.00 3.00 2a 0 54 61 65 75 81 81 Yield(%) 2 a 0 42 35 30 20 14 13 Yield (%) 90 80 70 60 50 40 30 20 10 0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Time (h) IGURE 1. Plots of the yields of 2a and 2 a against reaction time (h) for the gold-catalyzed aminofluorination of 1a. Curve a and b represent the change situation of the yield of 2a and 2 a with the reaction time, respectively. a b Characterization of all products (1) 4-luoro-3-methyl-1,5-diphenyl-1H-pyrazole (2a) 3 Purification by column chromatography (petroleum ether/etoac, 10/1) as a yellow oil (40.8 mg, 81%); R f = 0.49; IR (neat): = 3060, 2927, 2862, 1596, 1503, 1448, 1372 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.38 7.32 (m, 5H), 7.31 7.25 (m, 5H), 2.39 (s, 3H); 13 C MR (CDCl 3, 125 MHz): δ 146.5 (d, J = 248.8 Hz), 140.1, 136.4 (d, J = 11.3 Hz), 129.0, 128.9 (d, J = 2.5 Hz), 128.5, 128.4, 128.0 (d, J = 22.5 Hz), 127.6 (d, J = 3.8 Hz), 127.3, 124.7, 10.0 (d, J = 2.5 Hz); 19 MR (CDCl 3, 376 MHz): δ -175.3 (s); GC-MS (EI, 70eV): m/z (%) = 252(100) [M + ], 231(21), 180(13), 108(9), 77(35). (2) 4-luoro-3-methyl-1-phenyl-5-p-tolyl-1H-pyrazole (2b) S6

Purification by column chromatography (petroleum ether/etoac, 10/1) as a yellow oil (45.2 mg, 85%); R f = 0.46; IR (neat): = 3032, 2926, 2866, 1598, 1509, 1448, 1371 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.38 7.33 (m, 2H), 7.30 7.27 (m, 3H), 7.16 (m, 4H), 2.40 (s, 3H), 2.37 (s, 3H); 13 C MR (CDCl 3, 125 MHz): δ 146.3 (d, J = 247.5 Hz), 140.0, 138.5, 136.3 (d, J = 12.5 Hz), 129.9 (d, J = 5.0 Hz), 129.3, 129.0, 128.8 (d, J = 1.3 Hz), 128.2 (d, J = 21.3 Hz), 127.3, 124.8, 21.3, 10.0 (d, J = 2.5 Hz); 19 MR (CDCl 3, 376 MHz): δ -176.8 (s); GC- MS (EI, 70eV): m/z (%) = 266(100) [M + ], 245(17), 219(5), 194(10), 77(24); HRMS (EI) for C 17 H 15 2 : calcd. 266.1219, found 266.1202. (3) 4-luoro-5-(4-methoxyphenyl)-3-methyl-1-phenyl-1H-pyrazole (2c) O Purification by column chromatography (petroleum ether/etoac, 6/1) as a yellow oil (45.7 mg, 81%); R f = 0.44; IR (neat): = 3056, 2927, 2845, 1607, 1510, 1447, 1371, 1251, 1154 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.35 7.32 (m, 2H), 7.30 7.26 (m, 3H), 7.18 (d, J = 8.5 Hz, 2H), 6.88 (d, J = 9.0 Hz, 2H), 3.83 (s, 3H), 2.38 (s, 3H); 13 C MR (CDCl 3, 125 MHz): δ 159.6, 146.2 (d, J = 246.3 Hz), 140.2, 136.4 (d, J = 11.3 Hz), 130.2 (d, J = 1.3 Hz), 128.9, 127.9 (d, J = 22.5 Hz), 127.2, 124.7, 120.0 (d, J = 3.8 Hz), 114.1, 55.2, 10.1 (d, J = 2.5 Hz); 19 MR (CDCl 3, 376 MHz): δ -176.0 (s); GC-MS (EI, 70eV): m/z (%) = 282(100) [M + ], 267(31), 239(5), 210(5), 77(9); HRMS (EI) for C 17 H 15 2 O: calcd. 282.1168, found 282.1167. (4) 4-luoro-5-(2-methoxyphenyl)-3-methyl-1-phenyl-1H-pyrazole (2d) O Purification by column chromatography (petroleum ether/etoac, 10/1) as a yellow oil (46.8 mg, 83%); R f = 0.30; IR (neat): = 3065, 3006, 2934, 2841, 1594, 1499, 1464, 1372 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.40 7.37 (m, 1H), 7.30 7.19 (m, 6H), 7.02 (dd, J 1 =7.0, J 2 = 8.0 Hz, 1H), 6.86 (d, J = 8.0 Hz, 1H), 3.43 (s, 3H), 2.40 (s, 3H); 13 C MR (CDCl 3, 125 MHz): δ 156.7, 146.7 (d, J = 247.5 Hz), 141.0, 136.0 (d, J = 11.3 Hz), 132.9 (d, J = 161.3 Hz), 131.4, 130.8, 128.6, 125.3 (d, J = 23.8 Hz), 123.0, 120.8, 116.9 (d, J = 2.5 Hz), 111.4, 55.0, 10.1 (d, J = 2.5 Hz); 19 MR (CDCl 3, 376 MHz): δ -174.3 (s); GC-MS (EI, 70eV): m/z (%) = 282(100) [M + ], 261(23), 220(22), 118(11), 77(29); HRMS (EI) for C 17 H 15 2 O: calcd. 282.1168, found 282.1165. S7

(5) 5-(4-Ethoxyphenyl)-4-fluoro-3-methyl-1-phenyl-1H-pyrazole (2e) O Purification by column chromatography (petroleum ether/etoac, 6/1) as a yellow oil (47.3 mg, 80%); R f = 0.53; IR (neat): = 3062, 2978, 2927, 1606, 1512, 1372, 1248 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.35 7.32 (m, 2H), 7.29 7.26 (m, 3H), 7.16 (d, J = 8.5 Hz, 2H), 6.88-6.85 (d, J = 8.5 Hz, 2H), 4.05 (q, J =7.0 Hz, 2H), 2.38 (s, 3H), 1.43 (t, J = 7.0 Hz, 3H); 13 C MR (CDCl 3, 125 MHz): δ 159.0, 146.2 (d, J = 246.3 Hz), 140.2, 136.4 (d, J = 11.3 Hz), 130.2 (d, J = 2.5 Hz), 128.9, 128.0 (d, J = 23.8 Hz), 127.1, 124.7, 119.8 (d, J = 2.5 Hz), 114.6, 63.5, 14.8, 10.1 (d, J = 2.5 Hz); 19 MR (CDCl 3, 376 MHz): δ -176.1 (s); GC-MS (EI, 70eV): m/z (%) = 296(100) [M + ], 267(47), 247(9), 196(8), 77(21); HRMS (EI) for C 18 H 17 2 O: calcd. 296.1325, found 296.1330. (6) 5-(4-Ethylphenyl)-4-fluoro-3-methyl-1-phenyl-1H-pyrazole (2f) Purification by column chromatography (petroleum ether/etoac, 10/1) as a yellow oil (40.8 mg, 73%); R f = 0.44; IR (neat): = 3057, 2966, 2929, 2871, 1598, 1507, 1453, 1370 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.38 7.33 (m, 2H), 7.31 7.28 (m, 3H), 7.20 7.16 (m, 4H), 2.67 (q, J = 8.0 Hz, 2H), 2.39 (s, 3H), 1.25 (t, J = 7.8 Hz, 3H); 13 C MR (CDCl 3, 125 MHz): δ 146.3 (d, J = 247.5 Hz), 144.6, 140.1, 136.3 (d, J = 11.3 Hz), 130.0 (d, J = 5.0 Hz), 128.9, 128.8 (d, J = 2.5 Hz), 128.5 (d, J = 21.3 Hz), 128.1, 127.2, 124.7, 28.6, 15.2, 10.0 (d, J = 2.5 Hz); 19 MR (CDCl 3, 376 MHz): δ -175.5 (s); GC-MS (EI, 70eV): m/z (%) = 280(100) [M + ], 265(91), 251(4), 231(4), 77(20); HRMS (EI) for C 18 H 17 2 : calcd. 280.1376, found 280.1385. (7) 4-luoro-3-methyl-5-(4-pentylphenyl)-1-phenyl-1H-pyrazole (2g) Purification by column chromatography (petroleum ether/etoac, 10/1) as a yellow oil (48.2 mg, 75%); R f = 0.38; IR (neat): = 3056, 2928, 2860, 1595, 1510, 1453, 1372 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.35 7.32 (m, 2H), 7.30 7.27 (m, 3H), 7.17 7.15 (m, 4H), 2.61 (t, J = 7.8 Hz, 2H), 2.39 (s, 3H), 1.66 1.60 (m, 2H), 1.36 1.32 (m, 4H), 0.91 (t, J = 7.0 Hz, 3H); 13 C MR (CDCl 3, 125 MHz): δ 146.3 (d, J = 246.3 Hz), 143.4, 140.2, 136.4 (d, J = 11.3 Hz), 128.9, 128.7 (d, J = 2.5 Hz), 128.6, 128.2 (d, J = 21.3 Hz), 127.2, 124.8 (d, J = 3.8 Hz), 124.7, 35.7, 31.5, 30.8, 22.5, 14.0, 10.1 (d, J = 2.5 Hz); 19 MR (CDCl 3, 376 MHz): δ -175.4 (s); GC-MS S8

(EI, 70eV): m/z (%) = 322(66) [M + ], 265(100), 251(2), 204(2), 77(8); HRMS (EI) for C 21 H 23 2 : calcd. 322.1845, found 322.1836. (8) 5-(4-Chlorophenyl)-4-fluoro-3-methyl-1-phenyl-1H-pyrazole (2h) Cl Purification by column chromatography (petroleum ether/etoac, 10/1) as a yellow solid (36.7 mg, 64%); mp 65.1 65.8 ºC; R f = 0.57; IR (KBr): = 3061, 2928, 2861, 1594, 1500, 1441, 1370 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.37 7.30 (m, 5H), 7.26 (d, J = 8.5 Hz, 2H), 7.18 (d, J = 8.5 Hz, 2H), 2.38 (s, 3H); 13 C MR (CDCl 3, 125 MHz): δ 146.5 (d, J = 247.5 Hz), 139.7, 136.5 (d, J = 11.3 Hz), 134.5, 130.0 (d, J = 2.5 Hz), 129.2, 128.9, 127.6, 127.0 (d, J = 22.5 Hz), 125.9 (d, J = 3.8 Hz), 124.8, 10.0 (d, J = 1.3 Hz); 19 MR (CDCl 3, 376 MHz): δ -175.9 (s); GC-MS (EI, 70eV): m/z (%) = 286(100) [M + ], 265(14), 250(5), 108(8), 77(31); HRMS (EI) for C 16 H 12 Cl 2 : calcd. 286.0673, found 286.0672. (9) 5-(2-Chlorophenyl)-4-fluoro-3-methyl-1-phenyl-1H-pyrazole (2i) Cl Purification by column chromatography (petroleum ether/etoac, 10/1) as a yellow-brown solid (41.8 mg, 73%); mp 77.6 78.8 ºC; R f = 0.49; IR (KBr): = 3065, 2928, 2862, 1594, 1508, 1447, 1369 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.38 7.30 (m, 5H), 7.27 7.23 (m, 3H), 7.08 (d, J = 7.5 Hz, 1H), 2.39 (s, 3H); 13 C MR (CDCl 3, 125 MHz): δ 146.6 (d, J = 248.8 Hz), 139.7, 136.6 (d, J = 11.3 Hz), 134.5, 129.8, 129.3 (d, J = 3.8 Hz), 129.1, 128.7 (d, J = 2.5 Hz), 128.5, 127.6, 127.0 (d, J = 2.5 Hz), 126.6 (d, J = 21.3 Hz), 124.8, 10.0 (d, J = 2.5 Hz); 19 MR (CDCl 3, 376 MHz): δ -174.8 (s); GC-MS (EI, 70eV): m/z (%) = 286(100) [M + ], 265(21), 250(7), 214(10), 77(37); HRMS (EI) for C 16 H 12 Cl 2 : calcd. 286.0673, found 286.0669. (10) 5-(4-Bromophenyl)-4-fluoro-3-methyl-1-phenyl-1H-pyrazole (2j) Br Purification by column chromatography (petroleum ether/etoac, 10/1) as a yellow oil (45.6 mg, 69%); R f = 0.51; IR (neatr): = 3060, 2928, 2864, 1595, 1499, 1435, 1369 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.49 7.47 (m, 2H), 7.38 7.30 (m, 3H), 7.26 (m, J = 8.5 Hz, 2H), 7.12 (d, J = 8.5 Hz, 2H), 2.38 (s, 3H); 13 C MR (CDCl 3, 125 MHz): δ 146.5 (d, J = 248.8 Hz), 139.8, 136.6 (d, J = 11.3 Hz), 131.9, 130.3 (d, J = 1.3 Hz), S9

129.1, 127.5, 126.9 (d, J = 22.5 Hz), 126.5 (d, J = 5.0 Hz), 124.8, 122.7, 10.0 (d, J = 2.5 Hz); 19 MR (CDCl 3, 376 MHz): δ -175.8 (s); GC-MS (EI, 70eV): m/z (%) = 330(100) [M + ], 311(14), 250(10), 118(17), 77(52); HRMS (EI) for C 16 H 12 Br 2 : calcd. 330.0168, found 330.0167. (11) 4-luoro-3-methyl-1-phenyl-5-(thiophen-2-yl)-1H-pyrazole (2k) S Purification by column chromatography (petroleum ether/etoac, 10/1) as a yellow-brown oil (44.8 mg, 87%); R f = 0.49; IR (neat): = 3072, 2928, 2861, 1597, 1505, 1453, 1373 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.43 7.34 (m, 6H), 7.03 7.02 (m, 2H), 2.37 (s, 3H); 13 C MR (CDCl 3, 125 MHz): δ 146.1 (d, J = 250.0 Hz), 139.7, 136.1 (d, J = 11.3 Hz), 129.1, 128.3, 127.6 (d, J = 2.5 Hz), 127.2, 127.0, 125.9, 123.2 (d, J = 22.5 Hz), 115.1 (d, J = 135.0 Hz), 10.0 (d, J = 3.8 Hz); 19 MR (CDCl 3, 376 MHz): δ -173.3 (s); GC-MS (EI, 70eV): m/z (%) = 258(100) [M + ], 237(20), 216(9), 186(11), 77(29); HRMS (EI) for C 14 H 11 2 S: calcd. 258.0627, found 258.0610. (12) 5-Butyl-4-fluoro-3-methyl-1-phenyl-1H-pyrazole (2l) Purification by column chromatography (petroleum ether/etoac, 10/1) as a yellow oil (36.1 mg, 78%); R f = 0.33; IR (neat): = 3065, 2958, 2930, 2866, 1599, 1509, 1460, 1381 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.48 7.45 (m, 2H), 7.40 7.37 (m, 3H), 2.68 (t, J = 7.5 Hz, 2H), 2.3 (s, 3H), 1.55 1.49 (m, 2H), 1.33 1.26 (m, 2H), 0.86 (t, J = 7.5 Hz, 3H); 13 C MR (CDCl 3, 125 MHz): δ 146.8 (d, J = 242.5 Hz), 140.1, 135.6 (d, J = 11.3 Hz), 129.1, 128.6 (d, J = 23.8 Hz), 127.7, 125.1, 30.0, 23.4 (d, J = 3.8 Hz), 22.2, 13.6, 9.9; 19 MR (CDCl 3, 376 MHz): δ -177.5 (s); GC-MS (EI, 70eV): m/z (%) = 232(67) [M + ], 203(15), 190(100), 169(16), 77(29); HRMS (EI) for C 14 H 17 2 : calcd. 232.1376, found 232.1380. (13) 5-Benzyl-4-fluoro-3-methyl-1-phenyl-1H-pyrazole (2m) Purification by column chromatography (petroleum ether/etoac, 10/1) as a yellow oil (39.3 mg, 74%); R f = 0.44; IR (neat): = 3062, 3031, 2935, 2856, 1600, 1505, 1455, 1380 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.41 7.33 (m, 3H), 7.28 7.26 (m, 4H), 7.23 7.20 (m, 1H), 7.08 (d, J = 7.5 Hz, 2H), 4.02 (s, 2H), 2.34 (s, 3H); 13 C MR (CDCl 3, 125 MHz): δ 147.1 (d, J = 251.3 Hz), 139.4, 137.3, 135.7 (d, J = 11.3 Hz), S10

129.1, 128.7, 128.1, 127.9, 127.1 (d, J = 25.0 Hz), 126.7, 125.1, 29.4 (d, J = 2.5 Hz), 10.0 (d, J = 2.5 Hz); 19 MR (CDCl 3, 376 MHz): δ -176.9 (s); GC-MS (EI, 70eV): m/z (%) = 266(100) [M + ], 251(9), 189(25), 91(12), 77(19); HRMS (EI) for C 17 H 15 2 : calcd. 266.1219, found 266.1223. (14) 5-tert-Butyl-4-fluoro-3-methyl-1-phenyl-1H-pyrazole (2n) Purification by column chromatography (petroleum ether/etoac, 10/1) as a yellow oil (34.8 mg, 75%); R f = 0.47; IR (neat): = 3063, 2967, 2874, 1598, 1508, 1371, 1291 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.44 7.41 (m, 3H), 7.35 7.33 (m, 2H), 2.25 (s, 3H), 1.22 (d, J = 1.5 Hz, 9H); 13 C MR (CDCl 3, 125 MHz): δ 145.3 (d, J = 243.8 Hz), 142.5, 136.1 (d, J = 17.5 Hz), 135.5 (d, J = 13.8 Hz), 129.0, 128.7, 128.6, 32.4 (d, J = 3.8 Hz), 30.2 (d, J = 3.8 Hz), 9.8 (d, J = 2.5 Hz); 19 MR (CDCl 3, 376 MHz): δ -171.5 (s); GC-MS (EI, 70eV): m/z (%) = 232(41) [M + ], 217(100), 197(2), 182(4), 77(12). HRMS (EI) for C 14 H 17 2 : calcd. 232.1376, found 232.1377. (15) 4-luoro-3-methyl-1-phenyl-5-(trimethylsilyl)-1H-pyrazole (2o) Si Purification by column chromatography (petroleum ether/etoac, 10/1) as a yellow oil (21.4 mg, 43%); R f = 0.48; IR (neat): = 3062, 2960, 2862, 1600, 1505, 1406, 1256 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.46 7.41 (m, 3H), 7.40 7.37 (m, 2H), 2.31 (s, 3H), 0.14 (d, J = 1.0 Hz, 9H); 13 C MR (CDCl 3, 125 MHz): δ 156.5 (d, J = 246.3 Hz), 142.6, 135.7 (d, J = 13.8 Hz), 128.8, 128.3, 128.1 (d, J = 30.0 Hz), 126.2, 9.4 (d, J = 2.5 Hz), -0.8; 19 MR (CDCl 3, 376 MHz): δ -169.6 (s); GC-MS (EI, 70eV): m/z (%) = 248(83) [M + ], 233(100), 218(5), 171(21), 130(13), 77(47). HRMS (EI) for C 13 H 17 2 Si: calcd. 248.1145, found 248.1139. (16) 3-Ethyl-4-fluoro-1,5-diphenyl-1H-pyrazole (2p) Purification by column chromatography (petroleum ether/etoac, 10/1) as a yellow oil (35.6 mg, 67%); R f = 0.47; IR (neat): = 3060, 2970, 2928, 2861, 1596, 1506, 1449, 1379, 1336 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.34 7.30 (m, 5H), 7.28 7.23 (m, 5H), 2.79 (q, J = 7.5 Hz, 2H), 1.36 (t, J = 7.8 Hz, 3H); 13 C MR (CDCl 3, 125 MHz): δ 146.1 (d, J = 247.5 Hz), 141.9 (d, J = 10.0 Hz), 140.1, 129.0, 128.9 (d, J = 2.5 Hz), 128.6, 128.4, 128.1 (d, J = 22.5 Hz), 127.6 (d, J = 5.0 Hz), 127.3, 124.8, 18.8 (d, J = S11

2.5 Hz), 12.9; 19 MR (CDCl 3, 376 MHz): δ -176.5 (s); GC-MS (EI, 70eV): m/z (%) = 266(100) [M + ], 251(33), 231(2), 180(8), 77(33); HRMS (EI) for C 17 H 15 2 : calcd. 266.1219, found 266.1222. (17) 4-luoro-1,5-diphenyl-3-propyl-1H-pyrazole (2q) Purification by column chromatography (petroleum ether/etoac, 10/1) as a yellow oil (35.2 mg, 63%); R f = 0.51; IR (neat): = 3061, 2962, 2931, 2872, 1594, 1505, 1451, 1377 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.37 7.32 (m, 5H), 7.30 7.26 (m, 5H), 2.75 (t, J = 7.5 Hz, 2H), 1.85 1.78 (m, 2H), 1.06 (t, J = 7.3 Hz, 3H); 13 C MR (CDCl 3, 125 MHz): δ 146.3 (d, J = 248.8 Hz), 140.7 (d, J = 11.3 Hz), 140.1, 128.9(2C), 128.5, 128.3, 128.0 (d, J = 21.3 Hz), 127.7 (d, J = 3.8 Hz), 127.2, 124.8, 27.3 (d, J = 3.8 Hz), 22.0, 14.0; 19 MR (CDCl 3, 376 MHz): δ -175.3 (s); GC-MS (EI, 70eV): m/z (%)= 280(25) [M + ], 265(8), 252(100), 180(4), 77(21); HRMS (EI) for C 18 H 17 2 : calcd. 280.1376, found 280.1369. (18) 4-luoro-1,5-diphenyl-1H-pyrazole (2r) H Purification by column chromatography (petroleum ether/etoac, 10/1) as a colorless oil (42.8 mg, 90%); R f = 0.44; IR (neat): = 3065, 2925, 2854, 1596, 1551, 1508, 1476, 1444, 1381 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.36 7.30 (m, 6H), 7.28 7.23 (m, 4H), 6.09 (d, J = 5.5 Hz, 1H); 13 C MR (CDCl 3, 125 MHz): δ 164.2 (d, J = 243.8 Hz), 144.7, 139.4, 129.9, 128.9, 128.8, 128.7, 128.6, 127.5, 125.2, 91.7 (d, J = 23.8 Hz); 19 MR (CDCl 3, 376 MHz): δ -129.0 (d, J = 6.0 Hz); GC-MS (EI, 70eV): m/z (%) = 238(100) [M + ], 210(12), 190(12), 135(3), 77(15); HRMS (EI) for C 15 H 11 2 : calcd. 238.0906, found 238.0916. (19) 3-tert-Butyl-4-fluoro-1,5-diphenyl-1H-pyrazole (2s) t-bu Purification by column chromatography (petroleum ether/etoac, 10/1) as a pale-yellow solid (37.7 mg, 64%); mp 124.0 124.6 ºC; R f = 0.45; IR (KBr): = 3047, 2990, 2969, 2875, 1596, 1554, 1499, 1482, 1451, 1365 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.92 (d, J = 8.0 Hz, 2H), 7.50 7.46 (m, 3H), 7.45 7.41 (m, 4H), 7.33 (t, J = 7.3 Hz, 1H), 1.28 (d, J = 15.0 Hz, 9H); 13 C MR (CDCl 3, 125 MHz): δ 144.8 (d, J = S12

248.8 Hz), 142.5, 137.5 (d, J = 8.8 Hz), 137.4 (d, J = 18.8 Hz), 131.1 (d, J = 3.8 Hz), 129.3, 128.8, 128.7, 128.5, 127.9, 126.3 (d, J = 3.8 Hz), 32.7 (d, J = 3.8 Hz), 30.3 (d, J = 3.8 Hz); 19 MR (CDCl 3, 376 MHz): δ -166.9 (s); GC-MS (EI, 70eV): m/z (%) = 294(54) [M + ], 279(100), 243(3), 132(3), 77(10). HRMS (EI) for C 19 H 19 2 : calcd. 294.1532, found 294.1530. (20) 1-(2,4-Dichlorophenyl)-4-fluoro-5-phenyl-1H-pyrazole (2t) Cl Cl H Purification by column chromatography (petroleum ether/etoac, 10/1) as a yellow oil (50.3 mg, 82%); R f = 0.46; IR (neat): = 3071, 2927, 2859, 1554, 1507, 1480, 1389 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.45 (d, J = 2.0 Hz, 1H), 7.37 7.29 (m, 5H), 7.20 7.18 (m, 2H), 6.15 (d, J = 5.5 Hz, 1H); 13 C MR (CDCl 3, 125 MHz): δ 164.4 (d, J = 245.0 Hz), 147.0, 136.0, 135.7, 133.5, 130.9, 130.3, 129.2, 129.1, 128.7, 128.0, 127.9, 90.9 (d, J = 23.8 Hz); 19 MR (CDCl 3, 376 MHz): δ -128.7 (d, J = 6.0 Hz); GC-MS (EI, 70eV): m/z (%) = 306(60) [M + ], 271(100), 236(60), 109(18), 77(24); HRMS (EI) for C 15 H 9 Cl 2 2 : calcd. 306.0127, found 306.0125. (21) 1-(2,4-Dichlorophenyl)-4-fluoro-3-methyl-5-phenyl-1H-pyrazole (2u) Cl Cl Purification by column chromatography (petroleum ether/etoac, 10/1) as a yellow oil (35.9 mg, 56%); R f = 0.48; IR (neat): = 3061, 2927, 2859, 1592, 1494, 1380, 1309, 1153 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.45 (d, J = 2.5 Hz, 1H), 7.37 7.31 (m, 5H), 7.22 7.20 (m, 2H), 2.39 (s, 3H); 13 C MR (CDCl 3, 125 MHz): δ 145.8 (d, J = 248.8 Hz), 137.5 (d, J = 11.3 Hz), 136.7, 135.5, 133.2, 130.8, 130.3, 129.9 (d, J = 21.3 Hz), 128.7, 128.6, 127.9, 127.2 (d, J = 3.8 Hz), 10.1 (d, J = 1.3 Hz); 19 MR (CDCl 3, 376 MHz): δ -175.5 (s); GC-MS (EI, 70eV): m/z (%) = 320(100) [M + ], 285(42), 265(56), 250(64), 109(28), 77(37); HRMS (EI) for C 16 H 11 Cl 2 2 : calcd. 320.0283, found 320.0279. (22) 4-luoro-3-methyl-1-(4-nitrophenyl)-5-phenyl-1H-pyrazole (2v) S13

O 2 Purification by column chromatography (petroleum ether/etoac, 10/1) as a yellow soild (38.1 mg, 64%); mp 125.8 127.1 ºC; R f = 0.45; IR (neat): = 3085, 2931, 2857, 1598, 1518, 1448, 1343 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 8.19 8.16 (m, 2H), 7.45 7.42 (m, 5H), 7.29 7.27 (m, 2H), 2.40 (s, 3H); 13 C MR (CDCl 3, 125 MHz): δ 147.3 (d, J = 250.0 Hz), 145.7, 144.8, 138.8 (d, J = 12.5 Hz), 129.3, 129.1, 129.0 (d, J = 2.5 Hz), 128.5 (d, J = 23.8 Hz), 127.0 (d, J = 3.8 Hz), 124.5, 123.7, 10.1 (d, J = 2.5 Hz); 19 MR (CDCl 3, 376 MHz): δ -174.3 (s); GC-MS (EI, 70eV): m/z (%) = 297(100) [M + ], 276(8), 250(20), 179(6), 77(10); HRMS (EI) for C 16 H 12 3 O 2 : calcd. 297.0914, found 297.0906. (23) 4-luoro-1,3-dimethyl-5-phenyl-1H-pyrazole (2w) Purification by column chromatography (petroleum ether/etoac, 10/1) as a yellow oil (18.6 mg, 49%); R f = 0.51; IR (neat): = 3060, 2928, 2856, 1586, 1533, 1501, 1454, 1372 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.52 7.49 (m, 2H), 7.45 7.42 (m, 3H), 3.80 (s, 3H), 2.30 (s, 3H); 13 C MR (CDCl 3, 125 MHz): δ 144.9 (d, J = 243.8 Hz), 133.8 (d, J = 11.3 Hz), 129.2, 129.0, 128.9, 128.8, 127.6 (d, J = 3.8 Hz), 37.9, 9.8 (d, J = 1.3 Hz); 19 MR (CDCl 3, 376 MHz): δ -178.5 (s); GC-MS (EI, 70eV): m/z (%) = 190(100) [M + ], 175(5), 146(8), 118(15), 77(13). HRMS (EI) for C 11 H 11 2 : calcd. 190.0906, found 190.0915. (24) 4-luoro-3-methyl-5-phenyl-1H-pyrazole (2x) H Purification by column chromatography (petroleum ether/etoac, 1/1) as a pale yellow soild (15.8 mg, 45%); mp 152.2 153.6 ºC; R f = 0.51; IR (KBr): = 3060, 2922, 2857, 1616, 1533, 1503, 1459 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.75 (d, J = 8.0 Hz, 2H), 7.42 (t, J = 7.8 Hz, 2H), 7.34 (m, 1H), 7.0 (br. s, 1H), 2.27 (s, 3H); 13 C MR (CDCl 3, 125 MHz): δ 145.1 (d, J = 242.5 Hz), 133.6 (d, J = 11.3 Hz), 130.1 (d, J = 20.0 Hz), 129.5 (d, J = 3.8 Hz), 128.8, 128.1, 125.8 (d, J = 3.8 Hz), 8.6 (d, J = 2.5 Hz); 19 MR (CDCl 3, 376 MHz): δ -177.7 (s); GC-MS (EI, 70eV): m/z (%) = 176(100) [M + ], 161(3), 146(7.0), 108(11), 77(19); HRMS (EI) for C 10 H 9 2 : calcd. 176.0750, found S14

176.0752. (25) 3-Methyl-1,5-diphenyl-1H-pyrazole (2'a) 4 H Purification by column chromatography (petroleum ether/etoac, 10/1) as a yellow oil (43.1 mg, 92%); R f = 0.32; IR (neat): = 3058, 2958, 2927, 2868, 1598, 1501, 1451, 1369 cm -1 ; 1 H MR (CDCl 3, 500 MHz): δ 7.34 7.27 (m, 8H), 7.25 7.23 (m, 2H), 6.34 (s, 1H), 2.41 (s, 3H); GC-MS (EI, 70eV): m/z (%) = 234(100) [M + ], 218(17), 192(13), 165(13), 77(27). References: 1. Aldeco-Pérez, E. J.; Álvarez-Toledano, C.; Toscano, A.; García-Estrada, J. G.; Penieres-Carrillo, J. G. Tetrahedron Lett. 2008, 49, 2942. 2. Zanka, A.; Uematsu, R.; Morinaga, Y.; Yasuda, H.; Yamazaki, H. Organic Process Research & Development 1999, 3, 389. 3. Joseph, C. S.; Carl, L. B.; W. David, L. J. luorine Chem. 2002, 118, 135. 4. Exier-Boullet,.; Klein, B.; Hamelin, J. Synthesis. 1986, 5, 409. S15

1 H, 13 C, and 19 MR spectra of all products 2a S16

2a S17

2a S18

2b S19

2b S20

2b S21

O 2c S22

O 2c S23

O 2c S24

O 2d S25

O 2d S26

O 2d S27

O 2e S28

O 2e S29

O 2e S30

2f S31

2f S32

2f S33

2g S34

2g S35

2g S36

Cl 2h S37

Cl 2h S38

Cl 2h S39

Cl 2i S40

Cl 2i S41

Cl 2i S42

Br 2j S43

Br 2j S44

Br 2j S45

S 2k S46

S 2k S47

S 2k S48

2l S49

2l S50

2l S51

2m S52

2m S53

2m S54

2n S55

2n S56

2n S57

Si 2o S58

Si 2o S59

Si 2o S60

2p S61

2p S62

2p S63

2q S64

2q S65

2q S66

2r H S67

2r H S68

2r H S69

2s t-bu S70

2s t-bu S71

2s t-bu S72

Cl Cl 2t H S73

Cl Cl 2t H S74

Cl Cl 2t H S75

Cl Cl 2u S76

Cl Cl 2u S77

Cl Cl 2u S78

O 2 2v S79

O 2 2v S80

O 2 2v S81

2w S82

2w S83

2w S84

H 2x S85

H 2x S86

H 2x S87

H 2'a S88