77716-06-4Relevant articles and documents
Chiral bicyclic phosphoramidites - A new class of ligands for asymmetric catalysis
Huttenloch, Oliver,Spieler, Jan,Waldmann, Herbert
, p. 671 - 675 (2001)
The development of new ligands for catalytic asymmetric C-C bond formation is of great interest to organic synthesis. We describe here a new class of chiral phosphoramidites that embody one or two binaphthol units attached to an achiral azabicyclic [3.3.1] or [3.3.0] framework. These ligands were easily accessible from (R)-1,1′-binaphthyl-2,2′-dioxaphosphorchloridite (4) and the corresponding heterobicyclic core 1, 2, or 3. They were employed in enantioselective Cu-catalyzed additions of different dialkylzinc reagents to cyclic and acyclic enones. The chiral ketones were obtained with an enantiomeric ratio up to 91:9. The choice of the best ligand proved to be strongly dependent on each substrate. In addition, ligand 6 was found to be the most suitable for Rh-catalyzed hydrogenations of α,β-unsaturated esters, giving rise to dimethyl 2-methylsuccinate and methyl N-acetylalaninate with enantiomer ratios up to 95:5.
Syntheses and a Conformational Study of Certain Selected 3-Oxa-7-azabicyclononan-9-ones. Single-Crystal X-ray Diffraction Analysis of 6,8-Bis(2-chlorophenyl)-3-oxa-7-azabicyclononan-9-one.
Arjunan, Palanisamy,Berlin, K. Darrell,Barnes, Charles L.,Helm, Dick van der
, p. 3196 - 3204 (2007/10/02)
Isomers of 2,4,6,8-tetraphenyl-3-oxa-7-azabicyclononan-9-ones, 6,8-bis(2-chlorophenyl)-3-oxa-7-azabicyclononan-9-one, and N-benzyl-3-oxa-7-azabicyclononan-9-one have been prepared by Mannich-type cyclocondensations with appropiate tet
