The preparation of trans-2, 5-dialkylpyrrolidinylbenzyldiphenylphosphines: new phosphinamine ligands for asymmetric catalysis

JP Cahill, FM Bohnen, R Goddard, C Krüger…

Index: Cahill, John P.; Bohnen, Frank M.; Goddard, Richard; Krueger, Carl; Guiry, Patrick J. Tetrahedron Asymmetry, 1998 , vol. 9, # 21 p. 3831 - 3839

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Citation Number: 30

Abstract

The preparation of new phosphinamine ligands 3a, 3b, possessing an enantiopure trans-2, 5-dialkylpyrrolidinyl unit is described. Of the three synthetic approaches investigated, two proved successful with similar overall yields of 50–60%. One approach forms the trans-2, 5- dialkylpyrrolidine unit first and then the diphenylphosphine is introduced whilst the other reverses the order of introduction. In each approach the key step is the cyclocondensation ...