Synthesis of new monodentate spiro phosphoramidite ligand and its application in Rh-catalyzed asymmetric hydrogenation reactions.
[reaction: see text] A new spirocyclic diol, 9,9'-spirobixanthene-1,1'-diol, was synthesized in two steps from readily available starting material m-phenoxyanisole. Resolution of the racemic diol was achieved by cocrystallization with N-benzylcinchonidinium chloride and N-benzylquininium chloride in acetonitrile. The corresponding spiro monodentate phosphoramidite ligand has been prepared for Rh-catalyzed asymmetric hydrogenation of alpha-dehydroamino acid derivatives and itaconic acid with excellent enantioselectivities (up to >99% ee).
Wu
Shulin
S
Department of Chemistry, 104 Chemistry Research Building, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Zhang
Weicheng
W
Zhang
Zhaoguo
Z
Zhang
Xumu
X
D002384:Catalysis; D006865:Hydrogenation; D007202:Indicators and Reagents; D008024:Ligands; D015394:Molecular Structure; D009943:Organophosphorus Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D012238:Rhodium / Q000737:chemistry*; D013141:Spiro Compounds / Q000138:chemical synthesis*
D007202:Indicators and Reagents; D008024:Ligands; D009943:Organophosphorus Compounds; D013141:Spiro Compounds; C434331:phosphoramidite; D012238:Rhodium