Enantioselective Catalysis of the Aza-Cope Rearrangement by a Chiral Supramolecular Assembly
The chiral supramolecular catalyst Ga{sub 4}L{sub 6} [L = 1,5-bis(2,3-dihydroxybenzoylamino)naphthalene] is a molecular tetrahedron that catalyzes the 3-aza-Cope rearrangement of allyl enammonium cations. This catalysis is accomplished by preorganizing the substrate in a reactive conformation within the host. This work demonstrates that through the use of enantiopure assembly, its chiral cavity is capable of catalyzing the 3-aza-Cope rearrangement enantioselectively, with yields of 21-74% and enantiomeric excesses from 6 to 64% at 50 C. At lower temperatures, the enantioselectivity improved, reaching 78% ee at 5 C. This is the highest enantioselectivity to date induced by the chiral cavity of a supramolecular assembly.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- Chemical Sciences Division
- DOE Contract Number:
- DE-AC02-05CH11231
- OSTI ID:
- 993492
- Report Number(s):
- LBNL-2886E; ISSN 1520-5126; TRN: US201023%%495
- Journal Information:
- Journal of the American Chemical Society, Vol. 131, Issue 48; ISSN 0002-7863
- Country of Publication:
- United States
- Language:
- English
Similar Records
Aza Cope Rearrangement of Propargyl Enammonium Cations Catalyzed By a Self-Assembled `Nanozyme
Diffusion of a Highly-Charged Supramolecular Assembly: Direct Observation of Ion-Association in Water