Chandra Mallojjala, S and Sarkar, R and Karugu, RW and Manna, MS and Ray, S and Mukherjee, S and Hirschi, JS (2022) Mechanism and Origin of Remote Stereocontrol in the Organocatalytic Enantioselective Formal C(sp2)-H Alkylation Using Nitroalkanes as Alkylating Agents. In: Journal of the American Chemical Society, 144 (38). pp. 17399-17406.
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Abstract
Experimental 13C kinetic isotope effects (KIEs) and density functional theory (DFT) calculations are used to evaluate the mechanism and origin of enantioselectivity in the formal C(sp2)-H alkylative desymmetrization of cyclopentene-1,3-diones using nitroalkanes as the alkylating agent. An unusual combination of an inverse (~0.980) and a normal (~1.033) KIE is observed on the bond-forming carbon atoms of the cyclopentene-1,3-dione and nitroalkane, respectively. These data provide strong support for a mechanism involving reversible carbon-carbon bond formation followed by rate- and enantioselectivity-determining nitro group elimination. The theoretical free-energy profile and the predicted KIEs indicate that this elimination event occurs via an E1cB pathway. The origin of remote stereocontrol is evaluated by distortion-interaction and SAPT0 analyses of the E1cB transition states leading to both enantiomers.
Item Type: | Journal Article |
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Publication: | Journal of the American Chemical Society |
Publisher: | American Chemical Society |
Additional Information: | The copyright for this article belongs to American Chemical Society |
Department/Centre: | Division of Chemical Sciences > Organic Chemistry |
Date Deposited: | 19 Oct 2022 10:45 |
Last Modified: | 19 Oct 2022 10:45 |
URI: | https://eprints.iisc.ac.in/id/eprint/77469 |
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