Tetrahedron letters

A highly enantioselective asymmetric hydrogenation route to β-(2R, 3S)-methyltryptophan

RS Hoerrner, D Askin, RP Volante, PJ Reider

Index: Hoerrner, R. Scott; Askin, David; Volante, R. P.; Reider, Paul J. Tetrahedron Letters, 1998 , vol. 39, # 21 p. 3455 - 3458

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Citation Number: 42

Abstract

Standard hydrogenation conditions: A solution of 2 (500 mg, 1.17 mmol) in MeOH (7.5 mL) was degassed with nitrogen for 15 min. A sample of (−)-1,2-Bis((2R, 5R)-2,5-dimethylphospholano )benzene(cyclooctadiene)rhodium (I) trifluoromethanesulfonate (7.5 mg, 0.011 mmol, purchased from STREM) was charged and the sample was hydrogenated (40 psi H 2 ) at 20°C for 24 h. The crude solution was filtered through silica gel (2:1 ethyl acetate/hexane) to remove the ...