Development of a new dimeric cyclophane ligand: application to enhanced diastereo- and enantioselectivity in the catalytic synthesis of beta-lactams.
We detail the synthesis of a new C(2)-symmetric bis(cyclophane) ligand system that can be thought of as electronically analogous to binol, but which possesses the added "third dimension" of cyclophane chirality. The ligand synthesis involves a spontaneous (but unexpected) atropisomerization to the desired product. We have employed this ligand to form a metal complex that is an effective cocatalyst for the highly enantio- and diastereoselective catalytic asymmetric synthesis of a beta-lactam.
Wack
Harald
H
Department of Chemistry, New Chemistry Building, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA.
France
Stefan
S
Hafez
Ahmed M
AM
Drury
William J
WJ
Weatherwax
Anthony
A
Lectka
Thomas
T
D002384:Catalysis; D019281:Dimerization; D004988:Ethers, Cyclic / Q000138:chemical synthesis*; D007769:Lactams / Q000138:chemical synthesis*; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D009284:Naphthols / Q000737:chemistry; D013237:Stereoisomerism
C406944:BINOL, naphthol; D004988:Ethers, Cyclic; D007769:Lactams; D008024:Ligands; D009284:Naphthols