(5Z)-5-(bromomethylidene)furan-2-one

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture containing 5-bromomethylene-2(5H) furanone (0.175 g, 1 mmol), 4-methoxyphenylboronic acid (0.182 g, 1.2 mmol), trans-dichlorobis(triphenylphosphine)palladium (II) (0.035 g, 0.05 mmol), tetrabutylammonium iodide (0.018 g, 0.05 mmol) and cesium fluoride (0.456 g, 3 mmol) in toluene (10 mL) and water (10 mL) were stirred at reflux for 24 hours under nitrogen. After cooling, brine (50 mL) was added and the product extracted with ethyl acetate (50 mL×3). The organic fractions were combined, washed with brine (50 mL×3), dried over anhydrous sodium sulfate and evaporated to dryness to give a brown solid. The resulting solid was chromatographed (silica gel: eluent 50:50 dichloromethane/light petroleum) giving the desired product 33 as a yellow powder. Yield 0.163 g (80%), m.p. 118-120° C., 1H NMR (CDCl3) δ 7.76-7.71 (m, 2H, H3′ and H5′), 7.45 (d, J=5.2 Hz, 1H, H4), 6.93-6.88 (m, 2H, H2′ and H6′), 6.14-6.12 (m, 1H, H3), 5.97 (bs, 1H, H6), 3.83 (s, 3H). 13C NMR (CDCl3, 75 MHz) δ 170.5 (C), 160.5 (C), 147.0 (C), 145.0 (C), 132.4 (CH), 125.6 (CH), 116.8 (CH), 114.3 (CH), 114.2 (CH), 55.3 CH3). IR (Nujol) 1789, 1737, 1604, 1551, 1509, 1458, 1376, 1302, 1258, 1175, 1119, 1025, 931, 893, 813 cm−1. at reflux for 24 hours under nitrogen After cooling the product extracted with ethyl acetate (50 mL×3) washed with brine (50 mL×3) dried over anhydrous sodium sulfate evaporated to dryness to give a brown solid The resulting solid was chromatographed (silica gel: eluent 50:50 dichloromethane/light petroleum)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture containing 5-bromomethylene-2(5H)furanone (0.175 g, 1 mmol), 2-thiopheneboronic acid (0.154 g, 1.2 mmol), trans-dichlorobis(triphenylphosphine)palladium (II) (0.035 g, 0.05 mmol), tetrabutylammonium iodide (0.018 g, 0.05 mmol) and cesium fluoride (0.456 g, 3 mmol) in toluene (10 mL) and water (10 mL) were stirred at reflux for 24 hours under nitrogen. After cooling, brine (50 mL) was added and the product extracted with ethyl acetate (50 mL×3). The organic fractions were combined, washed with brine (50 mL×3), dried over anhydrous sodium sulfate and evaporated to dryness to give a brown solid. The resulting solid was chromatographed (silica gel: eluent 50:50 dichloromethane/light petroleum) giving the desired product 32 as a yellow powder. Yield 0.170 g (95%), m.p. 100-102° C. 1H NMR (CDCl3) δ 7.50 (d, J=4.9 Hz, 1H, H3′), 7.46 (d, J=5.3 Hz, 1H, H4), 7.38 (d, J=3.4 Hz, 1H, H5′), 7.08-7.05 (m, 1H, H4′), 6.31 (s, 1H, H6), 6.17 (d, J=5.3 Hz, 1H, H3). 13C NMR (CDCl3, 75 MHz) δ 169.5 (C), 146.6 (C), 143.8 (CH), 136.0 (C), 131.3 (CH), 130.7 (CH), 127.7 (CH), 118.0 (CH), 107.5 (CH). IR (Nujol) 1777, 1738, 1459, 1417, 1376, 1107, 935, 886, 731 cm−1. at reflux for 24 hours under nitrogen After cooling the product extracted with ethyl acetate (50 mL×3) washed with brine (50 mL×3) dried over anhydrous sodium sulfate evaporated to dryness to give a brown solid The resulting solid was chromatographed (silica gel: eluent 50:50 dichloromethane/light petroleum)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture containing 5-bromomethylene-2(5H)furanone (0.175 g, 1 mmol), 3-trifluoromethylphenylboronic acid (0.228 g, 1.2 mmol), trans-dichlorobis(triphenylphosphine)palladium (II) (0.035 g, 0.05 mmol), tetrabutylammonium iodide (0.018 g, 0.05 mmol) and cesium fluoride (0.456 g, 3 mmol) in toluene (10 mL) and water (10 mL) were stirred at reflux for 24 hours under nitrogen. After cooling, brine (50 mL) was added and the product extracted with ethyl acetate (50 mL×3). The organic fractions were combined, washed with brine (50 mL×3), dried over anhydrous sodium sulfate and evaporated to dryness to give a brown solid. The resulting solid was chromatographed (silica gel: eluent 50:50 dichloromethane/light petroleum) giving the desired product 30 as a light brown powder. Yield 0.180 g (75%), m.p. 69-71° C., UV-Vis λmax (MeOH) 223 (15166), 323 (31738) nm. at reflux for 24 hours under nitrogen After cooling the product extracted with ethyl acetate (50 mL×3) washed with brine (50 mL×3) dried over anhydrous sodium sulfate evaporated to dryness to give a brown solid The resulting solid was chromatographed (silica gel: eluent 50:50 dichloromethane/light petroleum)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture containing 5-bromomethylene-2(5H)furanone (0.175 g, 1 mmol), 4-trifluoromethylphenylboronic acid (0.228 g, 1.2 mmol), trans-dichlorobis(triphenylphosphine)palladium (II) (0.035 g, 0.05 mmol), tetrabutylammonium iodide (0.018 g, 0.05 mmol) and cesium fluoride (0.456 g, 3 mmol) in toluene (10 mL) and water (10 mL) were stirred at reflux for 24 hours under nitrogen. After cooling, brine (50 mL) was added and the product extracted with ethyl acetate (50 mL×3). The organic fractions were combined, washed with brine (50 mL×3), dried over anhydrous sodium sulfate and evaporated to dryness to give a brown solid. The resulting solid was chromatographed (silica gel: eluent 50:50 dichloromethane/light petroleum) giving the desired product 29 as a light yellow powder. Yield 0.133 g (55%), m.p. 92-94° C., UV-Vis λmax (MeOH) 223 (15948), 237 (10856), 323(35739) nm. 1H NMR (CDCl3) δ 7.87 (d, J=8.3 Hz, 2H, H2′ and H6′), 7.63 (d, J=8.3 Hz, 2H, H3′ and H5′), 7.52 (d, J=5.7 Hz, 1H, H4), 6.28 (d, J=4.9 Hz, 1H, H3), 6.04 (s, 1H, H6). at reflux for 24 hours under nitrogen After cooling the product extracted with ethyl acetate (50 mL×3) washed with brine (50 mL×3) dried over anhydrous sodium sulfate evaporated to dryness to give a brown solid The resulting solid was chromatographed (silica gel: eluent 50:50 dichloromethane/light petroleum)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture containing 5-bromomethylene-2(5H)furanone (0.175 g, 1 mmol), 4-fluorophenylboronic acid (0.168 g, 1.2 mmol), trans-dichlorobis(triphenylphosphine)palladium (II) (0.035 g, 0.05 mmol), tetrabutylammonium iodide (0.018 g, 0.05 mmol) and cesium fluoride (0.456 g, 3 mmol) in toluene (10 mL) and water (10 mL) were stirred at reflux for 24 hours under nitrogen. After cooling, brine (50 mL) was added and the product extracted with ethyl acetate (50 mL×3). The organic fractions were combined, washed with brine (50 mL×3), dried over anhydrous sodium sulfate and evaporated to dryness to give a brown solid. The resulting solid was chromatographed (silica gel: eluent 50:50 dichloromethane/light petroleum) giving the desired product 28 as a white powder. Yield 0.164 g (86%), m.p. 140-142° C., UV-Vis λmax (MeOH) 225(22535), 330(56424) nm. at reflux for 24 hours under nitrogen After cooling the product extracted with ethyl acetate (50 mL×3) washed with brine (50 mL×3) dried over anhydrous sodium sulfate evaporated to dryness to give a brown solid The resulting solid was chromatographed (silica gel: eluent 50:50 dichloromethane/light petroleum)