New chiral monodentate phospholane ligands by highly stereoselective hydrophosphination
摘要:
New chiral phospholanes 6 were prepared in both enantiomeric forms starting from L- and D-tartaric acid. The key step in the synthetic sequence is the double hydrophosphination of unsaturated chiral bis(lactone) 9 by NaPhPH(BH3). This method was used for the first time in the formation of chiral phospholanes. The structure of phospholane 6a was confirmed by X-ray crystallography. sigma-Donor properties of the phospholanes were estimated by measurement of (1)J((PSe)-P-31-Se-77) coupling constants in the corresponding phosphine selenides. The new phospholanes were tested as ligands in the Rh-catalyzed enantioselective hydrogenation of functionalized standard olefins (65-92% ee). (c) 2006 Elsevier Ltd. All rights reserved.
New chiral monodentate phospholane ligands by highly stereoselective hydrophosphination
摘要:
New chiral phospholanes 6 were prepared in both enantiomeric forms starting from L- and D-tartaric acid. The key step in the synthetic sequence is the double hydrophosphination of unsaturated chiral bis(lactone) 9 by NaPhPH(BH3). This method was used for the first time in the formation of chiral phospholanes. The structure of phospholane 6a was confirmed by X-ray crystallography. sigma-Donor properties of the phospholanes were estimated by measurement of (1)J((PSe)-P-31-Se-77) coupling constants in the corresponding phosphine selenides. The new phospholanes were tested as ligands in the Rh-catalyzed enantioselective hydrogenation of functionalized standard olefins (65-92% ee). (c) 2006 Elsevier Ltd. All rights reserved.
New chiral phospholanes 6 were prepared in both enantiomeric forms starting from L- and D-tartaric acid. The key step in the synthetic sequence is the double hydrophosphination of unsaturated chiral bis(lactone) 9 by NaPhPH(BH3). This method was used for the first time in the formation of chiral phospholanes. The structure of phospholane 6a was confirmed by X-ray crystallography. sigma-Donor properties of the phospholanes were estimated by measurement of (1)J((PSe)-P-31-Se-77) coupling constants in the corresponding phosphine selenides. The new phospholanes were tested as ligands in the Rh-catalyzed enantioselective hydrogenation of functionalized standard olefins (65-92% ee). (c) 2006 Elsevier Ltd. All rights reserved.