CC1(C)C(C)(C)OB([C:9]2[CH2:10][CH2:11][N:12]([C:15]([O:17][C:18]([CH3:21])([CH3:20])[CH3:19])=[O:16])[CH2:13][CH:14]=2)O1.C([O-])([O-])=O.[K+].[K+].Br[C:30]1[CH:35]=[CH:34][C:33]([F:36])=[C:32]([N+:37]([O-:39])=[O:38])[CH:31]=1>CN(C=O)C>[F:36][C:33]1[CH:34]=[CH:35][C:30]([C:9]2[CH2:10][CH2:11][N:12]([C:15]([O:17][C:18]([CH3:19])([CH3:20])[CH3:21])=[O:16])[CH2:13][CH:14]=2)=[CH:31][C:32]=1[N+:37]([O-:39])=[O:38]To a 150-mL RB-flask containing tert-butyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,6-dihydro-1(2H)-pyridinecarboxylate (5.58 g, 16.5 mmol), K2CO3 (5.60 g, 40.5 mmol) and PdCl2dppf (1.48 mmol, 1.21 g) was added a solution of 4-bromo-1-fluoro-2-nitrobenzene (3.30 g, 15.0 mmol) in DMF (50.0 mL) at room temperature under argon. The mixture was heated to 80° C. under argon for 12 hours. After cooling to room temperature, the mixture was filtered through Celite and the Celite was washed with EtOAc (3×100 mL). The filtrates were washed with H2O (3×200 mL), brine (100 mL), dried over MgSO4, filtered and concentrated in vacuo. The crude material was purified by flash chromatography (EtOAc/hexanes 1:9) to afford tert-butyl 4-(4-fluoro-3-nitrophenyl)-3,6-dihydro-1(2H)-pyridinecarboxylate (3.13 g, 65.1%): 1H NMR (400 MHz, CDCl3) δ 8.06-7.89 (m, 1H), 7.66-7.49 (m, 1H), 7.30-7.10 (m, 1H), 6.19-5.95 (br, 1H), 4.10-3.95 (m, 2H), 3.58 (t, 2H, J=5.6 Hz), 2.49-2.34 (m, 2H), 1.42 (s, 9H).
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