Bis tetrahydrofuran-2-ylmethyl

Tellnratl(IV) Bis-[tetrahydrofuran-2-ylmethyl]- dichloro- E12b, 532 (En + TiCl4 Cyclokond.)... 

Bis(pyridin-2-ylmethyl)amine (0.57 g, 28 mmol) was dissolved in tetrahydrofuran (4 mL) together with triethylamine (0.8 g) and cooled to 0 °C. Upon addition of ethyl 3,5-bis(bromomethyl)-4-hydroxybenzoate (0.50 g, 14 mmol) in dichloro-methane (4 mL) a precipitate emerged immediately. The mixture was stirred for 48 h at room temperature, filtered and concentrated in vacuo. After further purification with column chromatography (ethyl acetate/methanol, 8 1, FeCla stain, Rf = 0.55) a brown oil was obtained (0.5 g, 61 %). 

To a solution of 2-methoxy-N-(pyridin-2-ylmethyl)aminoethanol (0.925 g, 5.6 mmol) and triethylamine (1.25 g) in tetrahydrofuran (10 mL) was added dropwise a solution of 4-bromo-2,6-bis(bromomethyl)phenol (1 g, 2.7 mmol) in dichloromethane (10 mL) at 0 °C. The reaction mixture was stirred for 72 h and filtered to remove the precipitate of triethylamine hydrobromide. Removal of the solvent resulted in a yellow oil which was further purified by flash column chromatography (1 g crude ligand, length = 30 cm, diameter = 1.5 cm, ethyl acetate (until firsthand is eluted) then methanol/ethyl acetate 1 5, FeCla stain, Rf = 0.55 in ethyl acetate). The ligand was obtained as a yellow oil (930 mg, 63 %). 

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