A study toward understanding the role of a phosphorus stereogenic center in (5S)-1,3-diaza-2-phospha-2-oxo-3-phenylbicyclo(3.3.0)octane derivatives as catalysts in the borane-mediated asymmetric reduction of prochiral ketones
Representative diastereomeric pairs of chiral catalysts, containing the (5S)-1,3-diaza-2-phospha-2-oxo-3-phenylbicyclo(3.3.0)octane moiety, with different stereochemistry at the phosphorus stereogenic center, have been synthesized and their stereoselection in the borane-mediated asymmetric reduction of representative prochiral ketones has been described. (c) 2005 Elsevier Ltd. All rights reserved.
Stereospecific Migration of P from N to Csp2: Ring-Expansion Reaction of Chiral Diazaphospholidine Oxides
作者:Olivier Legrand、Jean Michel Brunel、Gérard Buono
An addition-pseudorotation-elimination pathway is proposed for the first stereospecific ring-expansion reaction of chiral diazaphospholidine oxides by a 1,3-migration of P from N to Csp2 [Eq. (1)]. R=H, Ph; LDA=lithium diisopropylamide.