Aza Cope Rearrangement of Propargyl Enammonium Cations Catalyzed By a Self-Assembled `Nanozyme

Journal Article · Wed Feb 27 04:00:00 EST 2008 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/ja8013055· OSTI ID:961596

Hastings, Courntey J; Fiedler, Dorothea; Bergman, Robert G; Raymond, Kenneth N

The tetrahedral [Ga{sub 4}L{sub 6}]{sup 12-} assembly (L = N,N-bis(2,3-dihydroxybenzoyl)-1,5-diaminonaphthalene) encapsulates a variety of cations, including propargyl enammonium cations capable of undergoing the aza Cope rearrangement. For propargyl enammonium substrates that are encapsulated in the [Ga{sub 4}L{sub 6}]{sup 12-} assembly, rate accelerations of up to 184 are observed when compared to the background reaction. After rearrangement, the product iminium ion is released into solution and hydrolyzed allowing for catalytic turnover. The activation parameters for the catalyzed and uncatalyzed reaction were determined, revealing that a lowered entropy of activation is responsible for the observed rate enhancements. The catalyzed reaction exhibits saturation kinetics; the rate data obey the Michaelis-Menten model of enzyme kinetics, and competitive inhibition using a non-reactive guest has been demonstrated.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: Chemical Sciences Division
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 961596
• Report Number(s): LBNL-1507E
• Journal Information: Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society; ISSN JACSAT; ISSN 0002-7863
• Country of Publication: United States
• Language: English

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