Iodine → 2-(Phenylethynyl)benzo[b]thiophene-3-carbaldehyde

関与物質

反応手順

Benzo[b]thiophene-3-carbaldehyde (27) (162 mg, 1.0 mmol) in THF (2 mL) was added to a solution of TMPZnCl.LiCl (2) (1.3 M in THF, 0.85 mL, 1.1 mmol) at 25° C. and the reaction mixture was then stirred at this temperature for 30 min according to TP 2. I2 (381 mg, 1.5 mmol) dissolved in dry THF (2 mL) was then dropwise added and the resulting mixture was stirred for 0.5 h. To the solution of freshly generated in situ 2-iodobenzo[b]thiophene-3-carbaldehyde, NEt3 (7 mL), Cul (8 mg, 4 mol %), Pd(dba)2 (17 mg, 3 mol %) and P(o-furyl)3 (14 mg, 6 mol %) in THF (2 mL) and phenylacetylene (254 mg, 1.5 mol, 1.5 equiv) were successively slowly added. The reaction mixture was stirred at rt for 2 h. The reaction mixture was quenched with a sat. aq. Na2S2O3 solution (10 mL) and with a sat. aq. NH4Cl solution (20 mL), extracted with diethyl ether (3×50 mL) and dried over anhydrous Na2SO4. After filtration, the solvent was evaporated in vacuo. Purification by flash-chromatography (CH2Cl2/n-pentane, 1:2) furnished compound 29c (165 mg, 63%) as a yellowish solid.

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