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Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/12688

Title: DFT mechanistic studies on the regio-, stereo-,and enantio-selectivity of 1,3 dipolar cycloadditions of quinoliniumimides with olefins, maleimides, and benzynes for the synthesisof fused N,N′-heterocycles
Authors: Umar, Abdul Rashid
Tia, Richard
Adei, Evans
Keywords: Azomethine
Heterocycles
Oxazolidines
Diastereoselective
Global electrophilicity
Issue Date: 22-Jan-2020
Publisher: Springer-Verlag GmbH Germany
Citation: Journal of Molecular Modeling (2020) 26:36 https://doi.org/10.1007/s00894-020-4299-6
Abstract: This work investigated computationally the regio-, stereo-, and enantio-selectivity of the reactions of azomethine imines witholefins, maleimides, and benzynes, important reactions towards the synthesis of heteropolycyclic, N,N′-fused, spirocyclic sys-tems, which serve as building blocks for the synthesis of many pharmaceuticals, agrochemicals, and biologically active com-pounds. The results show that the thermally controlled diastereoselective [3 + 2] cycloaddition reaction between quinoliniumimide and methyl acrylate provides two regio-isomers: 1,4-regioisomer (N-C1, C-C2) and 1,3-regioisomer (N-C2, C-C1). The1,4-regioisomer hascisandtrans-stereoisomers while the 1,3-regioisomer has R-enantiomer and S-enantiomer, and the barriersfor the formation of these isomers are 5.1, 19.1, 10.7, and 10.5 kcal/mol, respectively. The reaction between quinolinium imideand maleimide leads to the formation of two stereoisomers;cis-isomer andtrans-isomer in which thecis-isomer is kinetically andthermodynamically favoured by 6.1 kcal/mol and 8.7 kcal/mol, respectively. The reaction between quinolinium imide andbenzyne also leads to the formation of two stereoisomers through one transition state, with a barrier of 3.0 kcal/mol. Globalelectrophilicity index calculations show that the dipole acts as a good electrophile in the reaction and decreasing or increasingelectrophilicity index has no correlation with the activation barriers.
Description: An article published by Springer-Verlag GmbH Germany and also available at https://doi.org/10.1007/s00894-020-4299-6
URI: http://hdl.handle.net/123456789/12688
Appears in Collections:College of Science

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