PDF《unactivated alkenes?》

50 mL). The combined organic layer was dried over Na2SO4, filtered and concentrated under reduced pressure to afford the residue S2, which could be used directly into next step without further purification. The substituted acetophenone (10 mmol) was dissolved in THF (30 mL) in a dried round bottom flask under an Ar atmosphere. The solution was cool down to -78 °C, followed by addition of lithium bis(trimethylsilyl)amide (LiHDMS) (20 mL,

1 M in THF). This solution was stirred at -78 °C for

1 h before the corresponding benzoyl chloride (10 mmol, 1.0 equiv) was added dropwise. The mixture was allowed to warm to room temperature stirred overnight. Then quenched with

1 M HCl (30 mL,

1 M) and water (100 mL), extracted with EtOAc (3 *

50 mL). The combined organic layer was dried over Na2SO4, filtered and concentrated under reduced pressure to afford the crude product, which was purified by flash column chromatography (petroleum ether/EtOAc 20:1) to give the corresponding product S3. S5? ? ? The obtained S3 (10 mmol) was dissolved in DMF (20 mL) in a dried round bottom flask, followed by addition of the corresponding allyl bromide S2 (11 mmol) and K2CO3 (2.07 g, 15mmol). The mixture was stirred at

65 °C for

6 h under an Ar atmosphere. Then diluted with Water (70 mL). extracted with EtOAc (3 *

50 mL). The combined organic layer was dried over Na2SO4, filtered and concentrated under reduced pressure to afford the crude product, which was purified by flash column chromatography (petroleum ether/EtOAc 20:1) to give the corresponding product 1. 2-(2-methylallyl)-1,3-diphenylpropane-1,3-dione (1a) ?

1 H NMR (400 MHz, CDCl3) δ 8.00 (dd, J = 5.2, 3.4 Hz, 4H), 7.64 C 7.55 (m, 2H), 7.47 (dd, J = 10.6, 4.8 Hz, 4H), 5.46 (t, J = 6.6 Hz, 1H), 4.81 (s, 1H), 4.72 (s, 1H), 2.88 (d, J = 6.6 Hz, 2H), 1.81 (s, 3H);

13 C NMR (101 MHz, CDCl3) δ 195.53, 142.58, 136.01, 133.55, 128.90, 128.61, 112.05, 55.74, 36.57, 22.99;

HRMS (ESI) m/z calcd for C19H19O2 [M+H]+ 279.1379, found 279.1374. 1,3-bis(4-fluorophenyl)-2-(2-methylallyl)propane-1,3-dione (1b)

1 H NMR (400 MHz, CDCl3) δ 8.11 C 7.89 (m, 4H), 7.15 (dd, J = 11.9, 5.2 Hz, 4H), 5.31 (t, J = 6.7 Hz, 1H), 4.81 (s, 1H), 4.69 (s, 1H), 2.87 (d, J = 6.6 Hz, 2H), 1.79 (s, 3H);

13 C NMR (101 MHz, CDCl3) δ 193.89, 166.01 (d, JC-F =

255 Hz), 142.31, 132.33 (d, JC-F = 2.9 Hz), 131.34 (d, JC-F = 9.4 Hz), 116.12 (d, JC-F = 20.9 Hz), 112.28, 56.31, 36.62, 22.90;

HRMS (ESI) m/z calcd for C19H17F2O2 [M+H]+ 315.1191, found 315.1184. 1,3-bis(4-chlorophenyl)-2-(2-methylallyl)propane-1,3-dione (1c) ? ? S6? ?

1 H NMR (400 MHz, CDCl3) δ 7.91 (d, J = 8.6 Hz, 4H), 7.45 (d, J = 8.6 Hz, 4H), 5.29 (t, J = 6.6 Hz, 1H), 4.81 (s, 1H), 4.68 (s, 1H), 2.85 (d, J = 6.6 Hz, 2H), 1.79 (s, 3H);

13 C NMR (101 MHz, CDCl3) δ 194.21, 142.17, 140.29, 134.20, 130.00, 129.30, 112.41, 56.28, 36.57, 22.89;

HRMS (ESI) m/z calcd for C19H17Cl2O2 [M+H]+ 347.0600, found 347.0593? ? 1,3-bis(4-bromophenyl)-2-(2-methylallyl)propane-1,3-dione (1d) ? ?

1 H NMR (400 MHz, CDCl3) δ 7.83 (d, J = 8.6 Hz, 4H), 7.62 (d, J = 8.6 Hz, 4H), 5.28 (t, J = 6.7 Hz, 1H), 4.81 (s, 1H), 4.68 (s, 1H), 2.85 (d, J = 6.6 Hz, 2H), 1.79 (s, 3H);

13 C NMR (101 MHz, CDCl3) δ 194.39, 142.14, 134.59, 132.30, 130.07, 112.43, 56.22, 36.55, 22.89;

HRMS (ESI) m/z calcd for C19H17Br2O2 [M+H]+ 434.9590, found 434.9578. ? 2-(2-methylallyl)-1,3-di-p-tolylpropane-1,3-dione (1e) ?

1 H NMR (400 MHz, CDCl3) δ 7.90 (d, J = 8.2 Hz, 4H), 7.26 (d, J = 8.0 Hz, 4H), 5.39 (t, J = 6.6 Hz, 1H), 4.79 (s, 1H), 4.71 (s, 1H), 2.86 (d, J = 6.6 Hz, 2H), 2.41 (s, 6H), 1.79 (s, 3H);