(3,5-dibromophenyl)boronic acid

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

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

Procedure: The colourless gum (E)-ethyl 3-(3′,5′-dibromo-biphenyl-4-yl)-but-2-enoate was prepared from (E)-ethyl 3-(4-iodophenyl)-but-2-enoate (example 91a) and 3,5-dibromobenzene boronic acid by a procedure analogous to that described in example 52a.

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

Procedure: The colourless gum (E)-ethyl 3-(3′,5′-dibromo-biphenyl-4-yl)-but-2-enoate was prepared from (E)-ethyl 3-(4-iodophenyl)-but-2-enoate (example 91a) and 3,5-dibromobenzene boronic acid by a procedure analogous to that described in example 52a.

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 3,5-dibromophenylboronic acid (2.58 g, 9.2 mmol), 2-bromo-3,3,3-trifluoroprop-1-ene (2.42 g, 13.8 mmol), K2CO3 (2.54 g, 18.4 mmol) and Pd(PPh3)2Cl2 (129 mg, 0.18 mmol) in THF (12 mL) and H2O (6 mL) was heated at 80° C. in a sealed tube for 4 h. The mixture was cooled to rt and partitioned between EA (50 mL) and H2O (50 mL). The aqueous layer was extracted with EA (50 mL) and the combined organic layers were dried over Na2SO4. The solvent was removed under reduced pressure and the crude product was purified by column chromatography on silica gel to give the crude desired product (2.3 g; 76% yield) as colorless oil. The mixture was cooled to rt partitioned between EA (50 mL) and H2O (50 mL) The aqueous layer was extracted with EA (50 mL) the combined organic layers were dried over Na2SO4 The solvent was removed under reduced pressure the crude product was purified by column chromatography on silica gel

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 3,5-dibromophenylboronic acid (2.58 g, 9.2 mmol), 2-bromo-3,3,3-trifluoroprop-1-ene (2.42 g, 13.8 mmol), K2CO3 (2.54 g, 18.4 mmol) and Pd(PPh3)2Cl2 (129 mg, 0.18 mmol) in THF (12 mL) and H2O (6 mL) was heated at 80° C. in a sealed tube for 4 h. The mixture was cooled to rt and partitioned between EA (50 mL) and H2O (50 mL). The aqueous layer was extracted with EA (50 mL) and the combined organic layers were dried over Na2SO4. The solvent was removed under reduced pressure and the crude product was purified by column chromatography on silica gel to give the crude desired product (2.3 g; 76% yield) as colorless oil. The mixture was cooled to rt partitioned between EA (50 mL) and H2O (50 mL) The aqueous layer was extracted with EA (50 mL) the combined organic layers were dried over Na2SO4 The solvent was removed under reduced pressure the crude product was purified by column chromatography on silica gel

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

Conditions: temp:40.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a degassed mixture of 5.0 g (17.9 mmol) of 3,5-dibromophenylboronic acid in 50 mL of THF and 25 mL of 2 M Na2CO3 (aqueous) was added 1.13 g (0.975 mmol) of Pd(PPh3)4 and 2.3 mL of 2-bromopropene. The mixture was stirred at 40° C. for 5 h, and the mixture was extracted with EtOAc. The organic layer was washed with 25 mL of brine, dried over Na2SO4, filtered, and concentrated. Purification by flash silica gel chromatography (10% EtOAc/hexanes) provided 1,3-dibromo-5-(prop-1-en-2-yl)benzene with some impurity. the mixture was extracted with EtOAc The organic layer was washed with 25 mL of brine dried over Na2SO4 filtered concentrated Purification by flash silica gel chromatography (10% EtOAc/hexanes)

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

Procedure: To 9.44 g of 1,3,5-tribromobenzene in 200 mL of diethyl ether was added 19.4 mL of 1.55M n-butyllithium in hexane at -78° under nitrogen. The suspension was stirred for 30 min, then added to 30 mL of trimethyl borate in 300 mL of diethyl ether at the same temperature. The now clear solution was stirred at -78° for 30 min then warmed to room temperature overnight. Fifty mL of 1 N hydrochloric acid were added and allowed to react for 2 h. The aqueous layer was discarded and the ether layer was extracted with 2 N sodium hydroxide solution (5 times with 100 mL). The extract was washed once with 50 mL of ether, then acidified with 6N HCl to pH 2 at 0°. A white precipitate was collected by filtration after the solution had been kept at 0° for 2 h. After air drying, 8.49 g (95%) of the title product was obtained. Melting point was >300° and the purity was confirmed by chromatography. The now clear solution was stirred at -78° for 30 min to react for 2 h the ether layer was extracted with 2 N sodium hydroxide solution (5 times with 100 mL) The extract was washed once with 50 mL of ether acidified with 6N HCl to pH 2 at 0° A white precipitate was collected by filtration after the solution had been kept at 0° for 2 h After air drying

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 3,5-dibromophenylboronic acid (2.58 g, 9.2 mmol), 2-bromo-3,3,3-trifluoroprop-1-ene (2.42 g, 13.8 mmol), K2CO3 (2.54 g, 18.4 mmol) and Pd(PPh3)2Cl2 (129 mg, 0.18 mmol) in THF (12 mL) and H2O (6 mL) was heated at 80° C. in a sealed tube for 4 h. The mixture was cooled to rt and partitioned between EA (50 mL) and H2O (50 mL). The aqueous layer was extracted with EA (50 mL) and the combined organic layers were dried over Na2SO4. The solvent was removed under reduced pressure and the crude product was purified by column chromatography on silica gel to give the crude desired product (2.3 g; 76% yield) as colorless oil. The mixture was cooled to rt partitioned between EA (50 mL) and H2O (50 mL) The aqueous layer was extracted with EA (50 mL) the combined organic layers were dried over Na2SO4 The solvent was removed under reduced pressure the crude product was purified by column chromatography on silica gel

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

Procedure: To 9.44 g of 1,3,5-tribromobenzene in 200 mL of diethyl ether was added 19.4 mL of 1.55 M n-butyllithium in hexane at -78° under nitrogen. The suspension was stirred for 30 min, then added to 30 mL of trimethyl borate in 300 mL of diethyl ether at the same temperature. The now clear solution was stirred at -78° for 30 min then warmed to room temperature overnight. Fifty mL of 1 N hydrochloric acid were added and allowed to react for 2 h. The aqueous layer was discarded and the ether layer was extracted with 2 N sodium hydroxide solution (5 times with 100 mL). The extract was washed once with 50 mL of ether, then acidified with 6N HCl to pH 2 at 0°. A white precipitate was collected by filtration after the solution had been kept at 0° for 2 h. After air drying, 8.49 g (95%) of the title product was obtained. Melting point was >300° and the purity was confirmed by chromatography. The now clear solution was stirred at -78° for 30 min to react for 2 h the ether layer was extracted with 2 N sodium hydroxide solution (5 times with 100 mL) The extract was washed once with 50 mL of ether acidified with 6N HCl to pH 2 at 0° A white precipitate was collected by filtration after the solution had been kept at 0° for 2 h After air drying

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

Procedure: To 9.44 g of 1,3,5-tribromobenzene in 200 mL of diethyl ether was added 19.4 mL of 1.55 M n-butyllithium in hexane at -78° under nitrogen. The suspension was stirred for 30 min, then added to 30 mL of trimethyl borate in 300 mL of diethyl ether at the same temperature. The now clear solution was stirred at -78° for 30 min then warmed to room temperature overnight. Fifty mL of 1 N hydrochloric acid were added and allowed to react for 2 h. The aqueous layer was discarded and the ether layer was extracted with 2 N sodium hydroxide solution (5 times with 100 mL). The extract was washed once with 50 mL of ether, then acidified with 6N HCl to pH 2 at 0°. A white precipitate was collected by filtration after the solution had been kept at 0° for 2 h. After air drying, 8.49 g (95%) of the title product was obtained. Melting point was >300° and the purity was confirmed by chromatography. The now clear solution was stirred at -78° for 30 min to react for 2 h the ether layer was extracted with 2 N sodium hydroxide solution (5 times with 100 mL) The extract was washed once with 50 mL of ether acidified with 6N HCl to pH 2 at 0° A white precipitate was collected by filtration after the solution had been kept at 0° for 2 h After air drying

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

Procedure: The colourless gum (E)-ethyl 3-(3′,5′-dibromo-biphenyl-4-yl)-but-2-enoate was prepared from (E)-ethyl 3-(4-iodophenyl)-but-2-enoate (example 91a) and 3,5-dibromobenzene boronic acid by a procedure analogous to that described in example 52a.