反应详情

To a solution of 1.21 g (10.0 mmol) B2, 2.89 g (11.0 mmol) triphenylphosphine and 1.20 g (11.0 mmol) pyridine-2-methanol in 30 ml dry tetrahydrofuran a solution of 1.92 g (11.0 mmol) diethyl azodicarboxylate in 5 ml dry tetrahydrofuran was added and the mixture was stirred at room temperature for 2 hours. After removal of the solvent and column chromatography on Silica (hexane/ethyl acetate 2:1) 2.81 g B3 were obtained as a light yellow oil (72% yield assuming 30 mol % impurity of triphenylphosphine oxide (measured by NMR)). Due to the problems with the separation of the impurities in this particular example the experiment was repeated with PS-bound triphenylphosphine to give pure B3 in 58% yield.

1. customAfter removal of the solvent and column chromatography on Silica (hexane/ethyl acetate 2:1) 2.81 g B3