Trifluoro-methanesulfonic acid 4-bromo-1-oxo-indan-5-yl ester (10.30 g, 28.68 mmol) is stirred in 50 mL of dry N,N-dimethylformamide under argon atmosphere. Zinc cyanide (1.01 g, 8.60 mmol), 1,1-bis(diphenylphosphino) ferrocene (1.58 g, 2.86 mmol) and tris(dibenzylideneacetone)dipalladium(0) (1.32 g, 1.44 mmol) are added the reaction mixture is warmed at 70° C. for 1 h. The reaction mixture is partioned between ethyl acetate and water, the organic phase is washed with brine, washed with water, dried over sodium sulfate and concentrated under vacuum. The crude product obtained is purified by flash chromatography (cyclohexane/ethyl acetate 99/01→50/50) to give the title compound (Yield: 2.2 g).
