Thiophene → Ethyl (E)-4-[2-(5,5-dimethyl-8-(2-thienyl)-5,6-dihydronaphthalen-2-yl)ethenyl]-benzoate

Participants

Reaction Conditions

Reaction Steps

A solution of lithiothiophene was prepared by the addition of 0.10 g (0.095 mL, 1.2 mmol) of thiophene to a cold solution (−78° C.) of 0.61 g (0.90 mL, 1.4 mmol, 1.6 M in hexanes) of n-butyl lithium in 2.0 mL of tetrahydrofuran. The solution was stirred at −78° C. for 35 min and then a solution of 0.158 g (1.2 mmol) of zinc chloride in 2.0 mL of tetrahydrofuran was added. The resulting solution was stirred at −78° C. to room temperature for 1 h and then the organozinc was added via cannula to a mixture of 0.212 g (0.44 mmol) of ethyl (E)-4-[2-(5,5-dimethyl-8-(trifluoromethylsulfonyl)oxy-5,6-dihydronaphthalen-2-yl)ethenyl]benzoate (Compound A9) and 18 mg (0.016 mmol) of tetrakis(triphenylphosphine)palladium(0) in 2.0 mL of tetrahydrofuran. The resulting mixture was stirred at room temperature for 10 min and then heated at 50° C. for 1 h. The reaction was quenched by the addition of sat. aqueous NH4Cl. The mixture was extracted with EtOAc (2×), and washed with brine. The organic phase was dried over Na2SO4 and then concentrated in vacuo. The crude material product was purified by flash chromatography (silica, 15% ethyl acetate in hexanes) to afford the title compound as a solid.

Provenance & Evidence