1. Screening Tables... p1. 2. General remarks and procedures... p2. 3. Experimental Section... p3. 4. NMR data... p Crystallographic data...

Transcript

1 Supporting Information Pascal Nösel, Laura Nunes dos Santos Comprido, Tobias Lauterbach, Matthias Rudolph, Frank Rominger, A. Stephen K. Hashmi* 1,5-Carbene Transfer: Gold-Catalyzed xidative Diyne Cyclizations rganisch-chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, Heidelberg, Germany Fax: (+49) Screening Tables... p1 2. General remarks and procedures... p2 3. Experimental Section... p3 4. NMR data... p14 5. Crystallographic data... p38 6. References... p49 S1

2 1. Screening Table Table 1. Solvent screening Entry Solvent Yield* 1 Dichloroethane 20% 2 Dioxane 12% 3 Toluene 11% 4 MeH 9% 5 MeCN 24% 6 DMF 7% *GC yields are averaged over a minimum of two runs using n-dodecane as an internal standard. Table 2. Variation of the oxidant Entry xidant Temp. Time Yield a 1 2,6-Lutidine N-oxide 55 C 16 h 60% 2 8-Isopropylquinoline N-oxide 55 C 16 h 78% 3 8-Isopropylquinoline N-oxide rt 16 h 52% b 4 Pyridine N-oxide 55 C 16 h 41% b 5 4-Picoline N-oxide 55 C 16 h 31% b ,6-dibromopyridine N-oxide 2,6-dibromopyridine N-oxide 3,5-dibromopyridine N-oxide 55 C 20 mins >49% c rt 1 h 97% rt 1 h 94% 9 Ph 2 S rt 3.5 h 56% a Isolated yields after column chromatography; b GC-yield using n-dodecane as an internal standard; c 49% pure product. Additional fractions contained product along with side-product. 2. General remarks and procedures: Chemicals were purchased from commercial suppliers and used as delivered. Dry solvents were dispensed from solvent purification system MB SPS-800. xygen-free, anhydrous reactions were carried out under an atmosphere of nitrogen. To degas the solvents, nitrogen was bubbled through them for at least 1 hour. NMR spectra were, if not mentioned otherwise, recorded at room temperature on the following spectrometers: Bruker ARX-250, Bruker Avance DRX-300 or Bruker Avance 500. Chemical S2

3 shifts are given in ppm and coupling constants in Hz. 1 H and 13 C spectra are calibrated in relation to deuterated solvents (CD 2 Cl 2 : 5.32 / ppm). 19 F spectra were calibrated in relation to the reference measurement of 1,2-difluorobenzene (-139 ppm). The following abbreviations were used for 1 H NMR to indicate the signal multiplicity: s (singlet), d (doublet), t (triplet), m (multiplet), dd (doublet of doublet), td (triplet of doublet), bs (broad singlet). All 13 C NMR spectra were measured with 1 H-decoupling. The multiplicities mentioned in this spectra [C (quarternary carbon), CH (CH-group), CH 2 (CH 2 -group), CH 3 (CH 3 -group)] were determined by DEPT135 spectra. For fluorine containing compounds, the second multiplicity refers to the 19 F-coupling. Mass Spectra (MS and HRMS) were determined in the Chemistry department of the Universität Heidelberg under the direction of Dr. J. Gross. EI+ spectra were obtained using a JEL JMD-700 spectrometer. For EI-MS, electrons with an energy of 70 ev were used. Infrared Spectroscopy (IR) was processed on an FT-IR BRUKER (IF528), IR PERKIN ELMER (283) or FT-IR Bruker Vektor 22. The solvent or matrix is denoted in brackets. For the most significant bands, the wave number (cm -1 ) is given. X-ray crystal structure analysis was measured on Bruker Smart CCD or Bruker Smart APEX instrument using Mo-K α radiation. Diffraction intensities were corrected for Lorentz and polarization effects. An empirical absorption correction was applied using SADABS based on the Laue symmetry of reciprocal space. Heavy atom diffractions were solved by direct methods and refined against F2 with the full matrix least square algorithm. Hydrogen atoms were either isotropically refined or calculated. The structures were solved and refined using the SHELXTL software package. Gas Chromatography / Mass Spectrometry (GC-MS) were carried out on two different systems: 1. HP 5972 Mass Selective Detector, coupled with a HP 5890 SERIES II plus Gas Chromatograph. 2. Agilent 5975C Mass Selective Detector, coupled with an Agilent 7890A Gas Chromatograph. In both cases, as a capillary column, an PTIMA 5 cross-linked Methyl Silicone column (30 m x, 0.32 mm, 0.25 mm) was employed and helium was used as the carrier gas. Gas Chromatography (GC) was carried out on a HP 5890 SERIES II plus Gas Chromatograph. As a capillary column, an PTIMA 5 cross-linked Methyl Silicone column (30 m x, 0.32 mm, 0.25 mm) was employed and nitrogen was used as the carrier gas. Melting points were measured in open glass capillaries in a Büchi melting point apparatus (according to Dr. Tottoli) and were not corrected. Flash column chromatography was carried out using Silica gel 60 ( mm / mesh ASTM purchased from Macherey-Nagel). Analytical Thin Layer Chromatography (TLC) was performed on pre-coated plastic sheets (Macherey-Nagel PLYGRAM SIL G/UV 254 ). Detection was accomplished using UV-light (254 nm), KMn 4 (in 1.5M Na 2 C 3 (aq.)) or vanillin/h 2 S 4 (in ethanol). 3. Experimental section: Synthesis of starting materials All substrates were easily synthesized in three-steps (Sonogashira cross-coupling, Seyferth-Gilbert homologation and Iodination). Most of them have previously been reported. 1-3 S3

4 1-(chloroethynyl)-2-(3,3-dimethylbut-1-yn-1-yl)benzene 1c 1-(3,3-dimethylbut-1-yn-1-yl)-2-ethynylbenzene (163 mg, 895 µmol) was dissolved in 20 ml of anhydrous THF under a nitrogen atmosphere. N-butyllithium (2.5M in hexane, 895 µl, 2.24 mmol) was added at 0 C and the solution was left to stir for 1 h at room temperature. Subsequently N-chlorosuccinimide (298 mg, 2.24 mmol) was added at 0 C. After stirring for 1h at room temperature the reaction was quenched with water. The organic layer was separated and the aqueous phase extracted with dichloromethane. The combined organic layers were dried over magnesium sulfate. The crude product was purified by flash column chromatography (Si 2, PE) furnishing 1c (119 mg, 549 µmol, 61%) as colorless oil. R f (silica, PE:EA=10:1) = 0.68; IR (Film): ν = 2968 cm -1, 2926, 2867, 2222, 1473, 1455, 1362, 1267, 886, 756; 1 H-NMR (300 MHz, CD 2 Cl 2 ): δ = 1.38 (s, 9H), (m, 2H), (m, 2H); 13 C-NMR (75 MHz, CD 2 Cl 2 ): δ = 28.6 (s), 31.2 (q, 3C), 68.9 (s), 71.6 (s), 78.0 (s), (s), (s), (d), (s), (d), (d), (d); MS (EI (+), 70 ev): m/z (%) = 216 (81) [M] +, 201 (44), 166 (55), 165 (100); HRMS (EI (+), 70 ev): C 14 H 14 Cl +, calculated: [M] + ; found: [M] +. 2-(3,3-dimethylbut-1-yn-1-yl)-1-(iodoethynyl)-4-methylbenzene 1h 1 Equivalent of 2-(3,3-dimethylbut-1-yn-1-yl)-1-ethynyl-4-methylbenzene (320 mg, 1.63 mmol) was dissolved in 30 ml of methanol. Potassium hydroxide (274 mg, 4.89 mmol) and subsequently N- Iodosuccinimide (477 mg, 2.11 mmol) were added at 0 C. After stirring for 1 h at room temperature the reaction was quenched with water and dichloromethane was added. The organic phase was dried over MgS 4 and the solvent was removed under reduced pressure. The crude product was further purified by flash column chromatography (Si 2, PE) furnishing 1h (480 mg, 1.49 mmol, 91%) as a yellow solid. M.p.: 72 C; R f (silica, PE:EA=10:1) = 0.65; IR (KBr): ν = 2967 cm -1, 2925, 2896, 2213, 2168, 1474, 1361, 1229, 1208, 882, 812, 582; 1 H-NMR (300 MHz, CDCl 3 ): δ = 1.36 (s, 9H), 2.30 (s, 3H), (m, 1H), 7.20 (bs, 1H), 7.28 (d, J H-H = 7.9 Hz, 1H); 13 C-NMR (75 MHz, CDCl 3 ): δ = 8.3 (s), 21.2 (q), 28.1 (s), 31.1 (q, 3C), 77.6 (s), 93.2 (s), (s), (s), (s), (d), (d), (d), (s); MS (EI (+), 70 ev): m/z (%) = 322 (100) [M] +, 307 (21), 180 (31), 179 (27), 165 (55); HRMS (EI (+), 70 ev): C 15 H 15 I +, calculated: [M] + ; found: [M] +. 3-(3,3-dimethylbut-1-yn-1-yl)-2-(iodoethynyl)thiophene S4

5 1l The TMS-protected alkyne ((3-(3,3-dimethylbut-1-yn-1-yl)thiophen-2-yl)ethynyl)trimethylsilane (891 mg, 3.42 mmol) was dissolved in 30 ml of methanol. Potassium hydroxide (768 mg, 13.7 mmol) and subsequently N-Iodosuccinimide (1.00 g, 4.45 mmol) were added at 0 C. After stirring for 1 h at room temperature the reaction was quenched with water and dichloromethane was added. The organic phase was dried over MgS 4 and the solvent was removed under reduced pressure. The crude product was further purified by flash column chromatography (Si 2, PE) furnishing 1l (912 mg, 2.90 mmol, 85%) as brown oil. R f (silica, PE:EA=10:1) = 0.51; IR (Film): ν = 2968 cm -1, 2926, 2899, 2219, 1510, 1454, 1278, 1219, 865, 728, 645; 1 H-NMR (300 MHz, CDCl 3 ): δ = 1.34 (s, 9H), 6.91 (d, J H-H = 5.2 Hz, 1H), 7.09 (d, J H-H = 5.2 Hz, 1H); 13 C-NMR (75 MHz, CDCl 3 ): δ = 14.2 (s), 28.2 (s), 31.1 (q, 3C), 73.1 (s), 86.5 (s), (s), (s), (d), (d), (s); MS (EI (+), 70 ev): m/z (%) = 314 (100) [M] +, 299 (44), 172 (38), 171 (72); HRMS (EI (+), 70 ev): C 12 H 11 IS +, calculated: [M] + ; found: [M] +. 1-(iodoethynyl)-2-(phenylethynyl)benzene I 1n 1 Equivalent of 1-ethynyl-2-(phenylethynyl)benzene (118 mg, 573 µmol) was dissolved in 20 ml of methanol. Potassium hydroxide (128 mg, 2.29 mmol) and subsequently N-Iodosuccinimide (167 mg, 744 µmol) were added at 0 C. After stirring for 2 h at room temperature the reaction was quenched with water and dichloromethane was added. The organic phase was dried over MgS 4 and the solvent was removed under reduced pressure. The crude product was further purified by flash column chromatography (Si 2, PE) furnishing 1n (139 mg, 424 µmol, 74%) as yellow oil. R f (silica, PE:EA=10:1) = 0.48; IR (reflection): ν = 3287 cm -1, 3078, 3059, 2978, 2216, 2168, 1670, 1557, 1472, 1277, 1068, 863, 761, 669; 1 H-NMR (300 MHz, CD 2 Cl 2 ): δ = (m, 2H), (m, 3H), (m, 4H); 13 C-NMR (100 MHz, CD 2 Cl 2 ): δ = 11.2 (s), 88.1 (s), 93.3 (s), 94.1 (s), (s), (s), (s), (d), (d, 2C), (d, 2C), (d), (d, 2C), (d); MS (EI (+), 70 ev): m/z (%) = 328 (100) [M] +, 202 (23), 201 (53), 200 (45); HRMS (EI (+), 70 ev): C 16 H 9 I +, calculated: [M] + ; found: [M] +. 2-(3,3-dimethylbut-1-yn-1-yl)cyclohex-1-enecarbaldehyde 2-bromocyclopent-1-enecarbaldehyde (1.84 g, 10.6 mmol), PdCl 2 (PPh 3 ) 2 (371 mg, 528 µmol) and CuI (100 mg, 528 µmol) were dissolved in 15 ml degassed NEt 3. After stirring for 10 minutes 3,3-dimethylbut- 1-yne (1.12 g, 13.7 mmol) was added and the mixture was stirred overnight at room temperature. Purification by column chromatography (Si 2, PE:EA, 50:1) delivered XY (1.41 g, 8.04 mmol, 76%) as yellow oil. S5

6 R f (Si 2, PE:EA, 20:1) = 0.63; IR (film): ν = 2969 cm -1, 2869, 2813, 2213, 1671, 1597, 1388, 1364, 1241, 707; 1 H NMR (300 MHz, CDCl 3 ): δ = 1.28 (s, 9H), 1.92 (quint, J= 7.7 Hz, 2H), 2.57 (t, J= 7.7 Hz, 2H), 2.65 (t, J= 7.7 Hz, 2H), (s, 1H); 13 C NMR (75 MHz, CDCl 3 ): δ = 22.0 (t), 28.5 (s), 29.3 (t), 30.6 (q, 3C), 39.2 (t), 73.4 (s), (s), (s), (s), (d); MS (EI (+), 70 ev): m/z (%) = 176 (5) [M] +, 161 (100); HRMS (EI (+), 70 ev): C 12 H 16 +, calculated: , [M] + ; found: [M] +. 1-(3,3-dimethylbut-1-yn-1-yl)-2-ethynylcyclopent-1-ene 2-(3,3-dimethylbut-1-yn-1-yl)cyclopent-1-enecarbaldehyde (400 mg, 2.27 mmol) was dissolved in 10 ml of anhydrous MeH and subsequently Cs 2 C 3 (2.22 g, 6.81 mmol) was added. Bestmann-hira-reagent (654 mg, 3.40 mmol) was added and the mixture was stirred overnight. Saturated aqueous NaHC 3 - solution was added and the mixture was extracted three times with DCM. The combined organic layers were dried over MgS 4 and the solvent was removed under reduced pressure. Purification by column chromatography (Si 2, PE) delivered XY (260 mg, 1.51 mmol, 67%) as yellow oil. R f (Si 2, PE) = 0.32; IR (film):ν= 3286 cm -1, 2969, 2850, 2214, 2094, 1476, 1362, 1204, 632; 1 H NMR (300 MHz, CDCl 3 ): δ = 1.27 (s, 9H), 1.89 (quint, J= 7.5 Hz, 2H), (m, 4H), 3.28 (s, 1H); 13 C NMR (75 MHz, CDCl 3 ): δ = 22.9 (t), 28.3 (s), 31.0 (q, 3C), 36.5 (t), 37.2 (t), 75.2 (s), 80.5 (s), 82.8 (d), (s), (s), (s); MS (EI (+), 70 ev): m/z (%) = 172 [M] + (97), 157 (88), 129 (100), 115 (63);HRMS (EI (+), 70 ev): C 13 H 16 +, calculated: , [M] + ; found: [M] +. 1-(3,3-dimethylbut-1-yn-1-yl)-2-(iodoethynyl)cyclopent-1-ene 11 1-(3,3-dimethylbut-1-yn-1-yl)-2-ethynylcyclopent-1-ene (220 mg, 1.28 mmol) was dissolved in 10 ml of anhydrous MeH. The mixture was cooled to 0 C and KH (179 mg, 3.19 mmol) was added. After stirring for 30 minutes NIS (374 mg, 1.66 mmol) was added and the mixture was stirred at room temperature for 2 h. After this time water was added and the mixture was extracted with DCM. The solvent was removed under reduced pressure to yield XY (375 mg, 1.26 mmol, 98%) as a brown solid. m.p.: 48 C; R f (PE) = 0.33; IR (ATR):ν= 3569 cm -1, 3162, 3076, 2971, 2930, 2901, 2866, 2367, 2288, 2205, 2152, 1774, 1698, 1474, 1454, 1438, 1389, 1362, 1339, 1297, 1269, 1241, 1203, 1134, 1029, 1004, 933, 882, 857, 824, 754, 692, 647, 607; 1 H NMR (400 MHz, C 6 D 6 ): δ = 1.23 (s, 9H), 1.40 (quint, J = 7.5 Hz, 2H), (m, 2H), (m, 2H); 13 C NMR (100 MHz, C 6 D 6 ): δ = 12.2 (s), 28.5 (s), 23.0 (t), 31.2 (q, 3C), 36.5 (t), 37.1 (t), 76.4 (s), 92.0 (s), (s), (s),133.9 (s); MS (EI (+)): m/z = 298 [M] + (100), 282 (24), 156 (21); HRMS (EI (+), 70 ev): C 13 H 15 I +, calculated: , [M] + ; found: [M] +. Gold-catalyzed cyclization products: 2-Iodo-3-(3-methylbut-2-en-2-yl)-1H-inden-1-one I 3a S6

7 1-(3,3-Dimethylbut-1-yn-1-yl)-2-(iodoethynyl)benzene (30.0 mg, 97.4 µmol) was dissolved in 0.40 ml of acetonitrile. 3,5-Dibromopyridine 1-oxide (1.5 equiv., 36.9 mg, 146 µmol) and Ph 3 PAuNTf 2 (5 mol%, 3.6 mg, 4.9 µmol) were added to the solution and the reaction mixture was left to stir at room temperature for 1 hour. The title compound was purified by flash chromatography eluting with (Si 2, PE:CH 2 Cl 2, 3:1) giving 3a as an orange solid (29.8 mg, 94%). m.p.: 58 ºC; R f (silica, PE:CH 2 Cl 2 : 2:1) = 0.27; IR (KBr): ν = 3419 cm -1, 3071, 2975, 2909, 2853, 1967, 1924, 1821, 1719, 1667, 1600, 1554, 1455, 1372, 1280, 1233, 1173, 1161, 1143, 1090, 1007; 1 H NMR (500 MHz, CD 2 Cl 2 ): δ = 1.66 (s, 3H), 1.80 (s, 3H), 1.90 (s, 3H), 6.96 (d, J = 7.1 Hz, 1H), 7.20 (t, J = 7.7 Hz, 1H), 7.34 (t, J = 7.2 Hz, 1H), 7.46 (d, J = 7.1 Hz, 1H); 13 C NMR (125 MHz, CD 2 Cl 2 ): δ = 16.6 (q), 20.0 (q), 22.8 (q), 96.1 (s), (d), (s), (d), (d), (s), (s), (d), (s), (s), (s); MS (EI (+), 70 ev): m/z (%) = 324 (100) [M] +, 308 (17), 281 (17), 197 (53), 182 (22), 179 (31), 165 (24), 154 (20), 152 (17); HRMS (EI (+), 70 ev): C 14 H 13 I +, calculated: [M] + ; found: [M] + ; UV-VIS (DCM): λ max [nm] (log ε) = 247 (5.58), 317 (4.51), 414 (4.31). 2-Bromo-3-(3-methylbut-2-en-2-yl)-1H-inden-1-one 3b 1-(Bromoethynyl)-2-(3,3-dimethylbut-1-yn-1-yl)benzene (50.0 mg, 192 µmol) was dissolved in 0.40 ml of acetonitrile. 3,5-Dibromopyridine 1-oxide (1.5 equiv., 72.7 mg, 287 µmol) and Ph 3 PAuNTf 2 (5 mol%, 7.1 mg, 9.6 µmol) were added to the solution and the reaction mixture was left to stir at room temperature overnight. The title compound was purified by flash chromatography eluting with (Si 2, PE:Et 2, 70:1) giving 3b as a bright yellow solid (48.0 mg, 90%). m.p. : 43 ºC; R f (silica, PE:Et 2, 70:1) = 0.30; IR (KBr): ν = 3425 cm -1, 2982, 2915, 1724, 1654, 1600, 1563, 1454, 1374, 1285, 1234, 1174, 1101; 1 H NMR (500 MHz, CD 2 Cl 2 ): δ = 1.68 (s, 3H), 1.88 (s, 3H), 1.92 (s, 3H), 6.96 (d, J = 7.2 Hz, 1H), 7.23 (t, J = 7.7 Hz, 1H), 7.36 (t, J = 7.2 Hz, 1H) ; 7.44 (d, J = 7.1 Hz, 1H); 13 C NMR (125 MHz, CD 2 Cl 2 ): δ = 16.7 (q), 20.1 (q), 22.9 (q), (s), (s), (d), (d), (d), (s), (s), (d), (s), (s), (s); MS (EI (+), 70 ev): m/z (%) = 276 (100) [M] +, 197 (74), 182 (36), 181 (19), 169 (78), 152 (27), 128 (16); HRMS (EI (+), 70 ev): C 14 H 13 Br +, calculated: [M] + ; found: [M] + ; UV-VIS (DCM): λ max [nm] (log ε) = 246 (4.40), 322 (3.28), 411 (2.84). 2-chloro-3-(3-methylbut-2-en-2-yl)-1H-inden-1-one 3c 1-(chloroethynyl)-2-(3,3-dimethylbut-1-yn-1-yl)benzene (53.0 mg, 245 µmol) was dissolved in 0.40 ml of acetonitrile. 3,5-Dibromopyridine 1-oxide (1.5 equiv., 92.8 mg, 367 µmol) and Ph 3 PAuNTf 2 (5 mol%, 9.04 mg, 12.2 µmol) were added to the solution and the reaction mixture was left to stir at room temperature for 30 min. The title compound was purified by flash chromatography eluting with (Si 2, PE:Et 2, 50:1) giving 3c as yellow oil (32.0 mg, 138 µmol, 57%). S7

8 R f (silica, PE:EA=10:1) = 0.55; IR (Film): ν = 2984 cm -1, 2921, 2857, 1729, 1602, 1569, 1455, 1113, 853, 715, 682; 1 H-NMR (300 MHz, CD 2 Cl 2 ): δ = 1.68 (s, 3H), 1.89 (s, 3H), 1.92 (s, 3H), 6.96 (d, J H-H = 7.2 Hz, 1H), (m, 1H), (m, 1H), 7.44 (d, J H-H = 7.1 Hz, 1H); 13 C-NMR (75 MHz, CD 2 Cl 2 ): δ = 16.8 (q), 20.3 (q), 23.0 (q), (s), (d), (d), (s), (d), (s), (d), (s), (s), (s), (s); MS (EI (+), 70 ev): m/z (%) = 232 (100) [M] +, 197 (25), 189 (37), 169 (48), 156 (20), 152 (20); HRMS (EI (+), 70 ev): C 14 H 13 Cl +, calculated: [M] + ; found: [M] + ; UV-VIS (DCM): λ max [nm] (log ε) = 245 (4.52), 321 (3.47), 400 (3.00). 2-Iodo-6-methoxy-3-(3-methylbut-2-en-2-yl)-1H-inden-1-one 3d 1-(3,3-Dimethylbut-1-yn-1-yl)-2-(iodoethynyl)-4-methoxybenzene (50.0 mg, 148 µmol) was dissolved in 0.40 ml of acetonitrile. 3,5-Dibromopyridine 1-oxide (1.5 equiv., 56.1 mg, 222 µmol) and Ph 3 PAuNTf 2 (5 mol%, 5.5 mg, 7.4 µmol) were added to the solution and the reaction mixture was left to stir at room temperature for 4.5 hours. The title compound was purified by flash chromatography eluting with (Si 2, PE:EtAc, 20:1) giving 3d as a dark red solid (44.3 mg, 85%). m.p. : 96 ºC; R f (silica, PE:EtAc, 20:1) = 0.53; IR (film): ν = 3432 cm -1, 2935, 2836, 1708, 1672, 1613, 1549, 1477, 1452, 1434, 1360, 1278, 1222, 1186, 1143, 1100, 1079, 1021; 1 H NMR (500 MHz, CD 2 Cl 2 ): δ = 1.66 (s, 3H), 1.87 (s, 3H), 1.89 (s, 3H), 3.81 (s, 3H), 6.75 (dd, J = 8.0, 2.4 Hz, 1H), 6.85 (d, J = 8.0, 1H), 7.06 (d, J = 2.4 Hz, 1H); 13 C NMR (125 MHz, CD 2 Cl 2 ): δ = 16.6 (q), 20.0 (q), 22.8 (q), 56.2 (q), 92.8 (s), (d), (d), (d), (s), (s), (s), (s), (s), (s),191.8 (s); MS (EI (+), 70 ev): m/z (%) = 354 (100) [M] +, 227 (34), 212 (14), 199 (11); HRMS (EI (+), 70 ev): C 15 H 15 I 2 +, calculated: [M] + ; found: [M] + ; UV-VIS (DCM): λ max [nm] (log ε) = 260 (4.59), 303 (3.50), 339 (3.35), 395 (2.89), 467 (3.08). 2-Iodo-5,6-dimethoxy-3-(3-methylbut-2-en-2-yl)-1H-inden-1-one 3e 1-(3,3-Dimethylbut-1-yn-1-yl)-2-(iodoethynyl)-4,5-dimethoxybenzene (60.0 mg, 163 µmol) was dissolved in 0.40 ml of acetonitrile. 3,5-Dibromopyridine 1-oxide (1.5 equiv., 61.8 mg, 244 µmol) and Ph 3 PAuNTf 2 (5 mol%, 6.0 mg, 8.2 µmol) were added to the solution and the reaction mixture was left to stir at room temperature for 2.5 hours. The title compound was purified by flash chromatography eluting with (Si 2, PE:EtAc, 3:1) giving 3e as a dark red oil (52.8 mg, 84%). R f (silica, PE:EtAc, 3:1) = 0.45; IR (film): ν = 3463 cm -1, 3413, 3071, 2933, 2861, 2835, 2676, 1716, 1663, 1590, 1554, 1491, 1462, 1409, 1373, 1344, 1308, 1275, 1213, 1188, 1130, 1077, 1015; 1 H NMR (500 MHz, CD 2 Cl 2 ): δ = 1.68 (s, 3H), 1.88 (s, 3H), 1.89 (s, 3H), 3.84 (s, 3H), 3.86 (s, 3H), 6.51 (s, 1H), 7.10 (s, 1H); 13 C NMR (125 MHz, CD 2 Cl 2 ): δ = 16.7 (q), 20.1 (q), 22.8 (q), 56.7 (q), 93.2 (s), (d), (d), (s), (s), (s), (s), (s), (s), (s),191.3 (s); MS (EI (+), 70 ev): m/z (%) = 384 (100) [M] +, 257 (21); HRMS (EI (+), 70 ev): C 16 H 17 I 3 +, calculated: [M] + ; found: [M] + ; UV-VIS (DCM): λ max [nm] (log ε) = 268 (4.49), 331 (3.58), 387 (2.67), 483 (2.56). S8

9 6-Iodo-7-(3-methylbut-2-en-2-yl)-5H-indeno[5,6-d][1,3]dioxol-5-one 3f 5-(3,3-Dimethylbut-1-yn-1-yl)-6-(iodoethynyl)benzo[d][1,3]dioxole (60.0 mg, 170 µmol) was dissolved in 0.40 ml of acetonitrile. 3,5-Dibromopyridine 1-oxide (1.5 equiv., 64.6 mg, 255 µmol) and Ph 3 PAuNTf 2 (5 mol%, 6.3 mg, 8.5 µmol) were added to the solution and the reaction mixture was left to stir at room temperature for 1.5 hours. The substance was purified by flash chromatography eluting with (Si 2, PE:EtAc, 30:1) giving 3f as a dark red solid (46.5 mg, 74%). m.p. : 127 ºC; R f (silica, PE:EtAc, 30:1) = 0.30; IR (film): ν = 3398 cm -1, 2913, 2767, 1713, 1665, 1585, 1556, 1501, 1471, 1373, 1348, 1318, 1271, 1222, 1164, 1133, 1089, 1036; 1 H NMR (500 MHz, CD 2 Cl 2 ): δ = 1.66 (s, 3H), 1.86 (s, 3H), 1.87 (s, 3H), 6.01 (s, 2H), 6.48 (s, 1H), 6.97 (s, 1H); 13 C NMR (125 MHz, CD 2 Cl 2 ): δ = 16.5 (q), 20.0 (q), 22.7 (q), 92.9 (s), (t), (d), (d), (s), (s), (s), (s), (s), (s), (s),190.4 (s); MS (EI (+), 70 ev): m/z (%) = 368 (100) [M] +, 241 (21), 226 (14) ); HRMS (EI (+), 70 ev): C 15 H 13 I 3 +, calculated: [M] + ; found: [M] + ; UV- VIS (DCM): λ max [nm] (log ε) = 268 (4.47), 391 (2.57), 410 (2.39), 482 (2.46). 7-iodo-6-(3-methylbut-2-en-2-yl)-8H-indeno[4,5-d][1,3]dioxol-8-one 3g 5-(3,3-dimethylbut-1-yn-1-yl)-4-(iodoethynyl)benzo[d][1,3]dioxole (53.6 mg, 152 µmol) was dissolved in 0.40 ml of acetonitrile. 3,5-Dibromopyridine 1-oxide (1.5 equiv., 57.7 mg, 228 µmol) and Ph 3 PAuNTf 2 (5 mol%, 5.63 mg, 7.61 µmol) were added to the solution and the reaction mixture was left to stir at room temperature for 3 hours. The substance was purified by flash chromatography eluting with (Si 2, PE:EtAc, 10:1) giving 3g as a red solid (45.0 mg, 122 µmol, 80%). M.p.: 99 C; R f (silica, PE:EA=2:1) = 0.48; IR (Film): ν = 2980 cm -1, 2856, 1707, 1547, 1434, 1373, 1159, 1130, 905, 778, 732; 1 H-NMR (300 MHz, CD 2 Cl 2 ): δ = 1.63 (d, J H-H = 1.2 Hz, 3H), (m, 6H), 6.10 (s, 2H), 6.43 (d, J H-H = 7.5 Hz, 1H), 6.61 (d, J H-H = 7.5 Hz, 1H); 13 C-NMR (75 MHz, CD 2 Cl 2 ): δ = 17.0 (q), 20.0 (q), 22.6 (q), 94.3 (s), (t), (d), (s), (d), (s), (s), (s), (s), (s), (s), (s); MS (EI (+), 70 ev): m/z (%) = 368 (100) [M] +, 241 (20), 213 (30), 183 (15), 155 (13); HRMS (EI (+), 70 ev): C 15 H 13 I 3 +, calculated: [M] + ; found: [M] + ; UV-VIS (DCM): λ max [nm] (log ε) = 258 (4.42), 366 (3.59), 453 (3.49). 2-Iodo-5-methyl-3-(3-methylbut-2-en-2-yl)-1H-inden-1-one S9

10 3h 2-(3,3-Dimethylbut-1-yn-1-yl)-1-(iodoethynyl)-4-methylbenzene (60.0 mg, 186 µmol) was dissolved in 0.40 ml of acetonitrile. 3,5-Dibromopyridine 1-oxide (1.5 equiv., 70.6 mg, 279 µmol) and Ph 3 PAuNTf 2 (5 mol%, 6.9 mg, 9.3 µmol) were added to the solution and the reaction mixture was left to stir at room temperature for 1.5 hours. The substance was purified by flash chromatography eluting with (Si 2, PE:EtAc, 30:1) giving 3h as a yellow solid (51.4 mg, 82%). m.p. : 108 ºC; R f (silica, PE:EtAc, 30:1) = 0.49; IR (KBr): ν = 3410 cm -1, 2973, 2917, 2856, 1714, 1664, 1559, 1555, 1465, 1448, 1377, 1350, 1280, 1234, 1167, 1131, 1089, 1038; 1 H NMR (500 MHz, CD 2 Cl 2 ): δ = 1.66 (s, 3H), 1.88 (s, 3H), 1.89 (s, 3H), 2.35 (s, 3H), 6.78 (s, 1H), 6.98 (d, J = 7.3 Hz, 1H), 7.34 (d, J = 7.3 Hz, 1H); 13 C NMR (125 MHz, CD 2 Cl 2 ): δ = 16.6 (q), 20.0 (q), 22.1 (q), 22.7 (q), 96.5 (s), (d), (s), (d), (s), (d), (s), (s), (s), (s), (s); MS (EI (+), 70 ev): m/z (%) = 338 (100) [M] +, 211 (43), 196 (19), 193 (15), 168 (13); HRMS (EI (+), 70 ev): C 15 H 15 I 3 +, calculated: [M] + ; found: [M] + ; UV-VIS (DCM): λ max [nm] (log ε) = 250 (4.63), 328 (3.57), 414 (2.98). 2-iodo-5,6-dimethyl-3-(3-methylbut-2-en-2-yl)-1H-inden-1-one 3i 1-(3,3-dimethylbut-1-yn-1-yl)-2-(iodoethynyl)-4,5-dimethylbenzene (51.2 mg, 152 µmol) was dissolved in 0.40 ml of acetonitrile. 3,5-Dibromopyridine 1-oxide (1.5 equiv., 57.8 mg, 228 µmol) and Ph 3 PAuNTf 2 (5 mol%, 5.63 mg, 7.61 µmol) were added to the solution and the reaction mixture was left to stir at room temperature for 3 hours. The substance was purified by flash chromatography eluting with (Si 2, PE:EtAc, 50:1) giving 3i as an orange solid (39.0 mg, 111 µmol, 73%). M.p.: 88 C; R f (silica, PE:EA=10:1) = 0.47; IR (Film): ν = 2977 cm -1,2921, 2856, 1718, 1552, 1401, 1351, 1177, 1061, 1019, 775, 727; 1 H-NMR (300 MHz, CD 2 Cl 2 ): δ = 1.66 (s, 3H), 1.88 (bs, 6H), 2.22 (s, 3H), 2.26 (s, 3H), 6.72 (s, 1H), 7.24 (s, 1H); 13 C-NMR (75 MHz, CD 2 Cl 2 ): δ = 16.7 (q), 19.9 (q), 20.1 (q), 20.6 (q), 22.8 (q), 95.2 (s), (s), (d), (d), (s), (s), (s), (s), (s), (s), (s); MS (EI (+), 70 ev): m/z (%) = 352 (100) [M] +, 225 (41), 210 (20), 197 (15), 182 (12); HRMS (EI (+), 70 ev): C 16 H 17 I +, calculated: [M] + ; found: [M] + ; UV-VIS (DCM): λ max [nm] (log ε) = 256 (4.91), 329 (2.72), 443 (3.19). 2-Iodo-3-(3-methylbut-2-en-2-yl)-6-nitro-1H-inden-1-one 3j S10

11 1-(3,3-Dimethylbut-1-yn-1-yl)-2-(iodoethynyl)-4-nitrobenzene (50.0 mg, 142 µmol) was dissolved in 0.40 ml of acetonitrile. 3,5-Dibromopyridine 1-oxide (1.5 equiv., 53.7 mg, 212 µmol) and Ph 3 PAuNTf 2 (5 mol%, 5.2 mg, 7.1 µmol) were added to the solution and the reaction mixture was left to stir at room temperature for 2 hours. The substance was purified by flash chromatography eluting with (Si 2, PE:EtAc, 10:1) giving 3j as a dark yellow solid (32.9 mg, 63%). m.p. : 159 ºC; R f (silica, PE:EtAc, 10:1) = 0.54; IR (KBr): ν = 3268 cm -1, 3081, 2922, 2120, 1736, 1644, 1599, 1485, 1451, 1428, 1371, 1338, 1324, 1306, 1254, 1223, 1186, 1160, 1114, 1089, 1054, 1014; 1 H NMR (500 MHz, CD 2 Cl 2 ): δ = 1.66 (s, 3H), 1.91 (s, 3H), 1.92 (s, 3H), 7.14 (d, J = 8.0 Hz, 1H), 8.24 (d, J = 2.0 Hz, 1H), 8.29 (dd, J = 8.0, 2.1 Hz, 1H); 13 C NMR (125 MHz, CD 2 Cl 2 ): δ = 16.6 (q), 20.2 (q), 23.0 (q), (s), (d), (d), (s), (d), (s), (s), (s), (s), (s),189.3 (s); MS (EI (+), 70 ev): m/z (%) = 369 (100) [M] +, 242 (45), 196 (21), 181 (10), 152 (14); HRMS (EI (+), 70 ev): C 14 H 12 IN 3 +, calculated: [M] + ; found: [M] + ; UV-VIS (DCM): λ max [nm] (log ε) = 240 (4.35), 294 (4.13), 331 (3.79), 413 (3.51). 6-Fluoro-2-iodo-3-(3-methylbut-2-en-2-yl)-1H-inden-1-one 3k 1-(3,3-Dimethylbut-1-yn-1-yl)-4-fluoro-2-(iodoethynyl)benzene (50.0 mg, 153 µmol) was dissolved in 0.40 ml of acetonitrile. 3,5-Dibromopyridine 1-oxide (1.5 equiv., 58.1 mg, 230 µmol) and Ph 3 PAuNTf 2 (7.5 mol%, 8.5 mg, 11.5 µmol) were added to the solution and the reaction mixture was left to stir at room temperature for 3.5 hours. The substance was purified by flash chromatography eluting with (Si 2, PE:Et 2, 70:1) giving 3k as an orange solid (39.1 mg, 75%). m.p. : 127 ºC; R f (silica, PE:Et 2, 70:1) = 0.49; IR (KBr): ν = 3422 cm -1, 3100, 2972, 2915, 2854, 1907, 1717, 1669, 1615, 1555, 1468, 1428, 1373, 1349, 1265, 1251, 1207, 1139, 1099, 1071 ; 1 H NMR (300 MHz, CD 2 Cl 2 ): δ = 1.66 (s, 3H), 1.81 (s, 3H), 1.89 (s, 3H), 6.92 (dd, J = 8.0, 4.6 Hz, 1H), 7.00 (td, J = 8.0, 2.4 Hz, 1H),7.19 (dd, J = 7.1, 2.4 Hz, 1H); 13 C NMR (125 MHz, CD 2 Cl 2 ): δ = 16.5 (q), 20.1 (q), 22.8 (q), 94.9 (d, J = 4.6 Hz), (d, J = 25.4 Hz), (d, J = 23.2 Hz), (s), (d, J = 8.1 Hz), (d, J = 6.9 Hz), (s), (d, J = 3.5 Hz), (d, J = Hz), (d, J = 2.3 Hz), (d, J = 1.2 Hz); 19 F NMR (470 MHz, CD 2 Cl 2 ): δ = ; MS (EI (+), 70 ev): m/z (%) = 342 (100) [M] +, 215 (34), 200 (17), 197 (20); HRMS (EI (+), 70 ev): C 14 H 12 FI +, calculated: [M] + ; found: [M] + ; UV-VIS (DCM): λ max [nm] (log ε) = 298 (5.26), 342 (5.19), 403 (4.95), 422 (4.98), 432 (4.98). 5-iodo-4-(3-methylbut-2-en-2-yl)-6H-cyclopenta[b]thiophen-6-one 3-(3,3-dimethylbut-1-yn-1-yl)-2-(iodoethynyl)thiophene (52.0 mg, 166 µmol) was dissolved in 0.40 ml of acetonitrile. 3,5-Dibromopyridine 1-oxide (1.5 equiv., 62.8 mg, 248 µmol) and Ph 3 PAuNTf 2 (10 mol%, 12.2 mg, 16.5 µmol) were added to the solution and the reaction mixture was left to stir at room temperature for 3.5 hours. The substance was purified by flash chromatography eluting with (Si 2, PE:EtAc, 50:1) giving 3l as orange oil (25.0 mg, 75.7 µmol, 45%). S11

12 3l R f (silica, PE:EA=10:1) = 0.43; IR (ATR): ν = 3113 cm -1, 2909, 2857, 1705, 1557, 1436, 1281, 1085, 1067, 758, 743; 1 H-NMR (300 MHz, CD 2 Cl 2 ): δ = 1.76 (bs, 3H), 1.84 (bs, 3H), 1.89 (s, 3H), 6.75 (d, J H-H = 4.6 Hz, 1H), 7.66 (d, J H-H = 4.6 Hz, 1H); 13 C-NMR (75 MHz, CD 2 Cl 2 ): δ = 16.5 (q), 20.4 (q), 23.4 (q), 92.1 (s), (d), (s), (s), (s), (d), (s), (s), (s); MS (EI (+), 70 ev): m/z (%) = 330 (100) [M] +, 203 (83), 188 (24), 175 (33), 160 (23); HRMS (EI (+), 70 ev): C 12 H 11 IS +, calculated: [M] + ; found: [M] + ; UV-VIS (DCM): λ max [nm] (log ε) = 253 (4.45), 332 (3.93), 393 (2.91), 413 (2.60), 477 (2.60). 3-benzoyl-2-iodo-1H-inden-1-one 1-(iodoethynyl)-2-(phenylethynyl)benzene (58.0 mg, 177 µmol) was dissolved in 0.40 ml of acetonitrile. 3,5-Dibromopyridine 1-oxide (1.5 equiv., 67.0 mg, 265 µmol) and Ph 3 PAuNTf 2 (5 mol%, 6.53 mg, 8.83 µmol) were added to the solution and the reaction mixture was left to stir at 55 C for 12 hours. The substance was purified by flash chromatography eluting with (Si 2, PE:EtAc, 100:1) giving 5 as an orange solid (12.0 mg, 33.3 µmol, 19%). 5 m.p.: 88 C; R f (silica, PE:EA=10:1) = 0.18; IR (Film): ν = 3058 cm -1, 2928, 1726, 1655, 1578, 1448, 1212, 1027, 904, 757, 701; 1 H-NMR (600 MHz, CD 2 Cl 2 ): δ = 6.95 (d, J H-H = 7.2 Hz, 1H), (m, 1H), (m, 1H), (m, 2H), 7.61 (d, J H-H = 7.0 Hz, 1H), (m, 1H), 8.00 (d, J H-H = 7.2 Hz, 2H); 13 C-NMR (150 MHz, CD 2 Cl 2 ): δ = 97.8 (s), (d), (d), (s), (d, 2C), (d), (d, 2C), (s), (d), (d), (s), (s), (s), (s) ; MS (EI (+), 70 ev): m/z (%) = 356 (100) [M] +, 234 (12), 233 (53), 205 (41), 105 (19); HRMS (EI (+), 70 ev): C 16 H 9 I 2 +, calculated: [M] + ; found: [M] + ; UV-VIS (DCM): λ max [nm] (log ε) = 248 (4.45), 325 (3.29), 429 (2.96). 1-(tert-butyl)-3,3,5,6-tetramethyl-2,3-dihydrocyclopenta [a] inden-8 (1H)-one 1,2-bis(3,3-dimethylbut-1-yn-1-yl)-4,5-dimethylbenzene (80.0 mg, 300 µmol) was dissolved in 0.50 ml of benzene. 8-isopropylquinoline N-oxide (1.3 equiv., 87.6 mg, 390 µmol) and IPrAuNTf 2 (5 mol%, 15.6 mg, 18.0 µmol) were added to the solution and the reaction mixture was left to stir at 80 C for 12 hours. The substance was purified by flash chromatography eluting with (Si 2, PE:EtAc, 100:1) furnishing a mixture of the desired product and the free pyridine. The latter was subsequently removed by Kugelrohr distillation giving 7 as a yellow crystalline solid (50.0 mg, 177 µmol, 59%). 7 S12

13 m.p.: 102 C; R f = 0.40 (PE/EtAc=10:1); IR (KBr): 2961 cm -1, 2867, 1696, 1610, 1463, 1402, 1368, 1118, 1098, 900, 889, 790; 1 H-NMR (500 MHz, CD 2 Cl 2 ): δ = 1.06 (s, 9H), 1.19 (s, 3H), 1.29 (s, 3H), 2.05 (dd, J H- H= 13.6, 6.0 Hz, 1H), 2.20 (s, 3H), (m, 1H), 2.23 (s, 3H), 2.92 (dd, J H-H = 14.8, 6.0 Hz, 1H), 6.91 (s, 1H), 7.03 (s, 1H); 13 C-NMR (125 MHz, CD 2 Cl 2 ): δ = 19.7 (q), 20.7 (q), 27.7 (q), 29.2 (q), 29.4 (q, 3C), 34.1 (t), 38.9 (s), 48.4 (s), 53.7 (d), (d), (d), (s), (s), (s), (s), (s), (s), (s); MS (ESI (+)): m/z (%) = 283 (4) [M+H] +, 305 (50) [M+Na] +, 321 (16) [M+K] + ; HRMS (ESI (+)): C 20 H 27 +, calculated: [M+H] + ; found: [M+H] +. 3-(3-methylbut-2-en-2-yl)-2-phenyl-1H-inden-1-one 1-(3,3-dimethylbut-1-yn-1-yl)-2-(phenylethynyl)benzene (50.0 mg, 193 µmol) was dissolved in 0.50 ml of benzene. 3,5-Dibromopyridine 1-oxide (1.3 equiv., 62.5 mg, 252 µmol) and IPrAuNTf 2 (10 mol%, 23.8 mg, 28.0 µmol) were added to the solution and the reaction mixture was left to stir at room temperature for 12 hours. The substance was purified by flash chromatography eluting with (Si 2, PE:EtAc, 100:1) furnishing a mixture of the desired product and the free pyridine. The latter was subsequently removed by Kugelrohr distillation giving 9 as a red solid (27.1 mg, 98.8 µmol, 51%). 9 m.p.: 61 C; R f = 0.63 (PE/EtAc=10:1); IR (film): = 3062 cm -1, 2925, 2855, 1780, 1598, 1490, 1456, 1374, 1175, 1140, 735, 700; 1 H-NMR (500MHz, CD 2 Cl 2 ) δ = 1.58 (s, 3H), 1.83 (s, 3H), 1.84 (s, 3H), 7.01 (d, J H-H = 7.2 Hz, 1H), (m, 2H), (m, 3H), 7.47 (d, J H-H = 7.0 Hz, 1H), 7.52 (d, J H-H = 7.2 Hz, 2H); 13 C-NMR (125 MHz, CD 2 Cl 2 ): δ = 17.6 (q), 20.2 (q), 23.0 (q), (d), (d), (s), (d), (d, 2C), (d, 2C), (d), (s), (s), (s), (s), (d), (s), (s), (s); MS (EI (+), 70 ev): m/z (%) = 151 (11), 162 (11), 189 (11), 215 (22), 219 (40), 244 (15), 259 (100), 260 (23), 274 (28) [M] + ;HRMS (EI (+), 70 ev): C 20 H 18 +, calculated: [M] + ; found: [M] + ; UV-VIS (DCM): λ max [nm] (log ε) = 266 (4.41), 355 (3.04), 431 (3.04). 3-(3-methylbut-2-en-2-yl)-2-(phenylethynyl)-1H-inden-1-one 2-Iodo-3-(3-methylbut-2-en-2-yl)-1H-inden-1-one (279 mg, 861 µmol), PdCl 2 (PPh 3 ) 2 (12.1 mg, 17.2 µmol, 2 mol%) and CuI (3.28 mg, 17.2 µmol, 2 mol%) were dissolved in 20 ml degassed NEt 3. After stirring for 10 minutes phenylacetylene (132 mg, 1.29 mmol, 1.5 eq) was added and the mixture was stirred overnight at room temperature. Purification by column chromatography (Si 2, PE:EA, 50:1) furnished 11 (239 mg, 801 µmol, 93%) as an orange oil. 12 R f (silica, PE:EA=10:1) = 0.35; IR (reflection): ν = 3063 cm -1, 3028, 2913, 2214, 1718, 1644, 1489, 1354, 1123, 799, 724; 1 H-NMR (300 MHz, CD 2 Cl 2 ): δ = 1.79 (s, 3H), 1.94 (s, 3H), 2.05 (s, 3H), 7.07 (d, J H-H = 7.2 Hz, 1H), (m, 8H); 13 C-NMR (75 MHz, CD 2 Cl 2 ): δ = 17.7 (q), 20.7 (q), 23.6 (q), 82.5 (s), (s), (s), (s), (d), (d), (s), (d, 2C), (d), (d), (s), (d, 2C), (d), (s), (s), (s), (s); MS (EI (+), 70 ev): m/z (%) = 298 (100) [M] +, 283 (44), 268 (15), 239 (23), 196 (25); HRMS (EI (+), 70 ev): C 22 H 18 +, calculated: [M] + ; found: [M] + ; UV-VIS (DCM): λ max [nm] (log ε) = 292 (4.51), 326 (3.92), 357 (3.42), 453 (3.50). S13

14 2-(4-hydroxyphenyl)-3-(3-methylbut-2-en-2-yl)-1H-inden-1-one 2-Iodo-3-(3-methylbut-2-en-2-yl)-1H-inden-1-one (140 mg, 432 µmol), Pd-PEPPSI-IPent (6.84 mg, 8.64 µmol, 2 mol%) and 4-hydroxyphenylboronic acid (71.5 mg, 518 µmol, 1.2 eq.) were dissolved in 10 ml anhydrous ethanol. After stirring for 10 minutes potassium tert-butoxide (58.1 mg, 518 µmol, 1.2 eq) was added and the mixture was for 48 h at room temperature. Purification by column chromatography (Si 2, PE:EA, 10:1) furnished 12 (71.0 mg, 245 µmol, 57%) as a red solid. 13 m.p.: 62 C; R f (silica, PE:EA=10:1) = 0.21; IR (ATR): ν = 3239 cm -1, 2918, 1682, 1596, 1511, 1435, 1374, 1227, 1140, 1105, 946, 853, 814, 763; 1 H-NMR (500 MHz, CD 2 Cl 2 ): δ = 1.79 (s, 3H), 13 C-NMR (125 MHz, CD 2 Cl 2 ): δ = 1.60 (s, 3H), 1.83 (s, 3H), 1.85 (s, 3H), 6.18 (s, 1H), 6.87 (d, J H-H = 8.6 Hz, 2H), 6.97 (d, J H-H = 7.2 Hz, 1H), 7.22 (t, J H-H = 7.3 Hz, 1H), 7.38 (t, J H-H = 7.3 Hz, 1H), (m, 3H); 13 C-NMR (100 MHz, CD 2 Cl 2 ): δ = 17.3 (q), 20.0 (q), 22.9 (q), (d, 2C), (d), (s), (d), (s), (d), (d, 2C), (s), (s), (s), (d), (s), (s), (s), (s); MS (ESI (-)): m/z (%) = 289 (100) [M-H]; HRMS (ESI (-)): C 20 H , calculated: [M-H]; found: [M-H]; UV-VIS (DCM): λ max [nm] (log ε) = 269 (4.53), 306 (3.71), 449 (3.30). 3-(cyclohex-1-en-1-yl)-2-iodo-1H-inden-1-one (3mb) and 3-(cyclopentylidenemethyl)-2-iodo-1Hinden-1-one (3ma) 3mb 3ma 1-(cyclopentylethynyl)-2-(iodoethynyl)benzene (100 mg, 312 µmol) was dissolved in 0.40 ml of acetonitrile. 3,5-Dibromopyridine 1-oxide (1.5 equiv., 118 mg, 468 µmol) and Ph 3 PAuNTf 2 (5 mol%, 11.5 mg, 15.6 µmol) were added to the solution and the reaction mixture was left to stir at room temperature for 5 hours. The crude product mixture was purified by flash chromatography eluting with (Si 2, PE:EtAc, 70:1) giving 2 fractions containing a 1:1 and a 2:1 mixture of compounds 3ma and 3mb (yield of 3ma: 25.2 mg, 72.0 µmol, 23%; yield of 3mb: 51.7 mg, 154 µmol, 49% ). Both fractions contained 3,5- dibromopyridine which was not separable by column chromatography. R f (silica, PE:EA=50:1) = 0.30; IR (of the mixture) (ATR): ν = 3066 cm -1, 3025, 2933, 2834, 2257, 1716, 1639, 1603, 1543, 1366, 1277, 1107, 1042, 1011, 922, 860, 707. Compound 3mb: 1 H-NMR (500 MHz, CD 2 Cl 2 ): δ = (m, 4H), (m, 1H), (m, 2H), (m, 1H), 6.08 (sept, J H-H = 1.9 Hz, 1H), (m, 1H), 7.19 (t, J H-H = 7.6 Hz, 1H), ), 7.33 (t, J H-H = 7.6 Hz, 1H), (m, 1H); 13 C-NMR (125 MHz, CD 2 Cl 2 ): δ = 22.2 (t), 22.7 (t), 25.6 (t), 27.2 (t), 94.0 (s), (s), (d), (d), (d), (s), (d), (d), (s), (s), (s). Compound 3ma: 1 H-NMR (500 MHz, CD 2 Cl 2 ): δ = (m, 4H), (m, 1H), (m, 2H), (m, 1H), 6.15 (quint, J H-H = 2.1 Hz, 1H), (m, 1H), 7.19 (t, J H-H = 7.6 Hz, 1H), ), 7.33 (t, J H-H = 7.6 Hz, 1H), (m, 1H); 13 C-NMR (125 MHz, CD 2 Cl 2 ): δ = 25.8 (t), 27.3 (t), 34.5 (t), 35.4 (t), 95.7 (s), (d), (s), (d), (d), (s), (d), (d), (s), (s), (s). MS (of the mixture)(ei (+), 70 ev): m/z (%) = 336 (100) [M] +, 209 (20), 165 (10), 143 (16); HRMS (EI (+), 70 ev): C 15 H 13 I +, calculated: [M] + ; found: [M] + S14

15 S15

16 S16 4. NMR Data ppm I ppm I

17 S ppm Cl ppm Cl

18 S I ppm S I ppm S18

19 ppm ppm S19

20 ppm ppm S20

21 ppm ppm S21

22 ppm S22

23 ppm ppm S23

24 ppm S24

25 ppm ppm S25

26 ppm ppm S26

27 ppm ppm S27

28 S ppm ppm Cl

29 S ppm Cl ppm I

30 S ppm I ppm I

31 S ppm I ppm I

32 I ppm S I ppm S32

33 S I ppm I ppm S33

34 S ppm I ppm I

35 I ppm S35

36 S ppm ppm

37 S ppm ppm

38 S ppm ppm

39 S ppm H ppm H

40 I I 2 : 1 mixture ppm I I 2 : 1 mixture ppm S40

41 I I 2 : 1 mixture ppm Crystallographic data: Crystal data and structure refinement for pno20: Identification code pno20 S41

42 Empirical formula C 14 H 13 I Formula weight Temperature 200(2) K Wavelength Å Crystal system triclinic Space group P 1 Z 2 Unit cell dimensions a = (2) Å α = (2) deg. b = (2) Å β = (1) deg. c = (3) Å γ = (1) deg. Volume (3) Å 3 Density (calculated) 1.70 g/cm 3 Absorption coefficient 2.51 mm -1 Crystal shape needle Crystal size 0.32 x 0.12 x 0.10 mm 3 Crystal colour yellow Theta range for data collection 1.9 to 28.5 deg. Index ranges -9 h 9, -10 k 10, -14 l 14 Reflections collected 8072 Independent reflections 3168 (R(int) = ) bserved reflections 2993 (I >2σ (I)) Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.79 and 0.50 Refinement method Full-matrix least-squares on F 2 Data/restraints/parameters 3168 / 64 / 206 Goodness-of-fit on F Final R indices (I>2 (I)) R1 = 0.025, wr2 = Largest diff. peak and hole 0.74 and eå -3 Table 1: Atomic coordinates and equivalent isotropic displacement parameters (Å 2 ) for pno20. U eq is defined as one third of the trace of the orthogonalized U ij tensor. Atom x y z U eq I (1) (1) (1) (1) C (3) (3) (2) (5) (4) (3) (2) (6) C (3) (3) (2) (5) C (10) (7) (4) 0.038(2) C (6) (6) (4) (13) C (7) (7) (5) (13) C (19) 0.782(2) (11) 0.049(3) C (2) 0.677(4) 0.168(2) 0.059(6) C (18) 0.684(3) 0.151(2) 0.042(4) C (3) (3) (2) (4) C (4) (3) (2) (6) C (6) (4) (3) (11) C (5) (4) (3) (9) C (4) (4) (2) (6) C (4) (3) (2) (5) C3B (8) (6) (4) (14) C4B (5) (5) (3) (10) C5B (6) (5) (4) (10) C6B (15) (18) (9) 0.046(2) C7B (14) 0.715(2) (18) 0.040(3) C8B (15) 0.679(3) (16) 0.048(4) S42

43 Table 2: Hydrogen coordinates and isotropic displacement parameters (Å 2 ) for pno20 Atom x y z U eq H6A H6B H6C H7A H7B H7C H8A H8B H8C H H H H H6B H6B H6B H7B H7B H7B H8B H8B H8B Table 3: Anisotropic displacement parameters (Å 2 ) for pno20. The anisotropic displacement factor exponent takes the form: -2 pi 2 (h 2 a *2 U h k a * b * U 12 ) Atom U 11 U 22 U 33 U 23 U 13 U 12 I (1) (1) (1) (1) (1) (1) C (12) (12) (11) (9) (9) (9) (18) (10) (11) (9) (11) (11) C (12) (12) (11) (9) (9) (10) C (5) 0.038(3) 0.029(3) 0.009(2) (2) (3) C (3) 0.034(2) 0.032(3) (19) (19) (19) C (3) 0.035(3) 0.030(3) 0.010(2) 0.009(2) 0.008(2) C (8) 0.058(5) 0.034(4) 0.014(3) 0.013(4) 0.014(5) C (6) 0.075(14) 0.066(13) 0.002(9) 0.026(7) 0.014(8) C (5) 0.050(9) 0.035(6) 0.008(6) 0.007(4) 0.025(4) C (11) (10) (10) (8) (8) (8) C (18) (12) (11) (9) (11) (11) C (3) (13) (14) (11) (17) (16) C (3) (13) (15) (11) (15) (15) C (17) (14) (12) (10) (11) (12) C (14) (12) (11) (10) (10) (10) C3B 0.034(4) 0.036(2) 0.027(2) (16) (17) (19) C4B 0.037(2) 0.035(2) 0.030(2) (15) (15) (15) C5B 0.044(2) 0.037(2) 0.027(2) (15) (16) (17) C6B 0.057(6) 0.053(4) 0.035(3) 0.018(2) 0.015(3) 0.015(4) C7B 0.037(3) 0.044(5) 0.041(5) 0.006(4) 0.003(2) 0.015(2) C8B 0.037(4) 0.059(9) 0.042(5) 0.002(5) 0.002(3) 0.003(5) Table 4: Bond lengths (Å) and angles (deg) for pno20 S43