Toluene → 2-Vinyl-(9,9-dimethyl)-fluorene

Participants

Reaction Conditions

Reaction Steps

8.19 g (25.6 mmole) of 2-iodo-(9,9-Dimethyl)-fluorene, 5.18 g (28.1 mmole) of dibutyl vinylborate, 0.26 g of Pd(PPh3)4, 60 ml of toluene, 30 ml of ethanol, and 60 ml of a 2M sodium carbonate aqueous solution were fed into a 300-ml round-bottomed flask, and the whole was stirred at 80° C. for 8 hours in a stream of nitrogen. After the completion of the reaction, the reaction liquid was extracted with toluene. The organic layer was washed with water and dried with magnesium sulfate, followed by evaporation to dryness under reduced pressure. The resultant was purified by means of silica gel column chromatography (eluent: hexane/ethyl acetate=10/1) to yield 3.5 g of 2-vinyl-(9,9-Dimethyl)-fluorene (62.1% yield). 1.05 g (4.77 mmole) of the obtained 2-vinyl-(9,9-Dimethyl)-fluorene and 10 ml of THF were fed into a 100-ml round-bottomed flask, and the whole was cooled to −5° C. in a stream of nitrogen. 6.21 ml of a 0.5M 9-BBN solution were slowly added dropwise to the resultant, and the whole was stirred at 0° C. for 2 hours. After that, 4.8 ml of a 3N aqueous solution of NaOH, 130 mg of PdCl2(dppf), and 956 mg (2.144 mmol) of 2,2′-diodo-(9,9-Dimethyl)-fluorene were added to the resultant, and the whole was stirred at 60° C. for 7 hours. After the completion of the reaction, the reaction liquid was extracted with toluene. The organic layer was washed with water and dried with magnesium sulfate, followed by evaporation to dryness under reduced pressure. Then, the resultant was recrystallized with toluene/hexane. After the obtained crystal had been removed by filtration, the remainder was purified by means of mother liquor silica gel column chromatography (eluent: hexane/ethyl acetate=5/1→1/1), recrystallized with toluene, dried in a vacuum, and subjected to sublimation purification to yield 272 mg of Compound 21 (20% yield).

Provenance & Evidence