Publication 152
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P. Müller, P. Nury, G. Bernardinelli,
“Asymmetric Catalysis with a Phosphoramidite Derived from (-)-(aR)- [1,1’-Binaphthalene]-8,8’-diol”
Helv. Chim. Acta 2000, 83, 843-854.
Treatment of (aR)-[1,1′binaphthalene]-8,8′-diol ((−)-1) with hexamethylphosphorous triamide afforded the N,N-dimethylphosphoramidite (−)-3 (Scheme?1). The synthesis of the analogous N,N-diisopropylphosphoramidite 4 failed, however, and afforded the acyclic phosphonamidate (−)-5. The application of the cyclic phosphoramidite (−)-3 towards asymmetric catalysis was investigated. The borane reduction of acetophenone (6) to (R)-1-phenylethanol (7) in the presence of (−)-3 proceeded with 96% ee (Scheme?2). The use of (−)-3 as ligand in several Cu-catalyzed addition and substitution reactions resulted in enantioselectivities ranging from 0 to 50% (Schemes?3 and 4).
DOI : 10.1002/(SICI)1522-2675(20000412)83:4<843::AID-HLCA843>3.0.CO;2-J
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