94% |
In tetrahydrofuran; for 0.5h;Schlenk technique; Inert atmosphere; Darkness; |
General procedure: General Procedure A dry Schlenk flask equipped with a Teflon-coated magnetic stir bar is charged with [(R-allyl)PdC1]2 (0.50 mmol, 0.50 equiv) followed by AgOTf (257 mg, 1.00 mmol, 1.00 equiv). The flask is fitted with a rubber septum evacuated and backfilled with nitrogen. This evacuationlnitrogen back-fill cycle is repeated two additional times. Solvent (10 mE THF or 2-MeTHF) is added and the reaction mixture is stirred at it for 30 mm while protected from light. A second dry Schienk flask is equipped with a magnetic stir bar, fitted with a Schlenk frit, and charged with the appropriate ligand(1.00 mmol, 1.00 equiv). The flask is fitted with a rubber septum and it is evacuated and backfilled with nitrogen. This evacuationlnitrogen backfill cycle is repeated two additional times. The solution from the first Schlenk flask is transferred via cannula through the Schienk frit (to remove AgC1) andinto the second Schlenk flask containing the ligand, rinsing with 5 mE of additional solvent (THF or 2-MeTHF). This mixture is stirred at it for 2 h. 30 mE of hexanes is then added to fully precipitate the product. The solid materials are then collected by suction filtration, washed with additional pentane (or hexanes), and dried in vacuo; The general procedure is followed using 183 mg (0.50mmol) of [(allyl)PdC1]2, 257mg (1.00 mmol) ofAgOTf, 537mg (1.00 mmol) of l3rettPhos in anhydrous THF to give 803mg (0.94 mmol, 94%) of the title compound as a yellowsolid. The material contains 3 wt % of THF.?H NMR (400 MHz, CDC13, oe): 7.34 (s, 1H), 7.23 (s, 1H),7.07-6.98 (m, 1H), 6.96-6.87 (m, 1H), 5.45 (sept, J=7.52 Hz,1H), 4.14 (d, J=6.8 Hz, 1H), 3.84 (s, 3H), 3.42 (dd, J=8.2,13.1 Hz, 1H), 3.29 (s, 3H), 2.90 (sept, J=8.2 Hz, 1H),2.79-2.63 (m, 1H), 2.59 (d, J=13.2 Hz, 1H), 2.55-2.41 (m,1H), 2.40-2.25 (m, 2H), 2.14 (sept, J=7.8 Hz, 1H), 1.98-1.82(m, 2H), 1.81-0.93 (m, 29H), 0.92-0.66 (m, 7H).?3C NMR (100 MHz, CDC13, oe): 154.8 (2 peaks), 153.3,151.4, 150.5, 135.0, 134.8, 125.6, 124.9, 124.8, 124.2,123.9, 122.4, 119.5, 119.4, 119.3, 115.2, 113.7, 112.7 (2peaks), 100.7, 100.5, 55.8, 54.7, 52.0, 38.5, 38.4, 38.3, 38.1,33.7, 32.5, 31.5, 30.0, 27.2, 26.7, 26.6, 24.3, 24.0, 23.9, 23.8[Observed complexity due to C-P and C-F coupling];peaks attributable to THF are observed at 67.7 and 25.4.3?P NMR (162 MHz, CDC13, oe): 51.4.?9F NMR (376 MHz, CDC13, oe): -78.4 (s, 3F). Anal. Calcd. for C39H58F3O5PPdS: C, 56.21; H, 7.02. Found: C, 56.46; H, 7.05. |