Diastereoselective Multicomponent [4+2]/[3+2] Cycloadditions of gamma-(S)-N,N-dibenzylamine Nitroalkenes Derivatives with Ethyl Vinyl Ether (EVE) and Electron-Poor Alkenes Using Li+- Containing Catalysts.

Diastereoselective Multicomponent [4+2]/[3+2] Cycloadditions of gamma-(S)-N,N-dibenzylamine Nitroalkenes Derivatives with Ethyl Vinyl Ether (EVE) and Electron-Poor Alkenes Using Li+- Containing Catalysts.

Vieira, Daniel Pais Pires; Carvalho, Leandro Lara de; Pereira, Vera Lúcia Patrocinio

Abstract:

Electrondeficient nitroalkenes exhibit different reactivities in organic synthesis. For example: i) act as dienophiles reacting with dienes to afford nitrocycloadducts derivatives in Diels-Alder reaction; ii) as 1,3-dipolarophiles (DPP) reacting with several 1,3-dipoles in [3+2] cycloadditions and iii) as heterodienes (HD), often in the presence of Lewis acid, to afford cyclic alkyl nitronates in hetero-Diels- Alder reactions. To the best of our knowledge, there are only two examples of the use of chiral nitroalkenes in stereoselective tandem [4+2]/[3+2] cycloadditions. Recently, we synthesized non-racemic nitroalkenes 3-5 from L-alanine, L-phenylalanine and L-leucine, respectively in five steps and 80-90% overall yield. Theses electrondeficient nitroalkenes have exhibited excellent stereochemical stability, reactivity and diastereoselectivity in a great number of different reactions. In order to increase the scope of the reactivity of 3-5 herein we investigate the reactivity and diastereoselectivity these new “chirons” in tandem intermolecular [4+2]/[3+2] cycloadditions employing Li+ containing catalysts.

Electrondeficient nitroalkenes exhibit different reactivities in organic synthesis. For example: i) act as dienophiles reacting with dienes to afford nitrocycloadducts derivatives in Diels-Alder reaction; ii) as 1,3-dipolarophiles (DPP) reacting with several 1,3-dipoles in [3+2] cycloadditions and iii) as heterodienes (HD), often in the presence of Lewis acid, to afford cyclic alkyl nitronates in hetero-Diels- Alder reactions. To the best of our knowledge, there are only two examples of the use of chiral nitroalkenes in stereoselective tandem [4+2]/[3+2] cycloadditions. Recently, we synthesized non-racemic nitroalkenes 3-5 from L-alanine, L-phenylalanine and L-leucine, respectively in five steps and 80-90% overall yield. Theses electrondeficient nitroalkenes have exhibited excellent stereochemical stability, reactivity and diastereoselectivity in a great number of different reactions. In order to increase the scope of the reactivity of 3-5 herein we investigate the reactivity and diastereoselectivity these new “chirons” in tandem intermolecular [4+2]/[3+2] cycloadditions employing Li+ containing catalysts.

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DOI: 10.5151/chempro-14bmos-R0138-2

Referências bibliográficas

• [1] 1Moura, A. L. S. PhD thesis, NPPN-UFRJ, Rio de Janeiro, 2007. Vieira, D. P. P. R.; MSc thesis NPPN-UFRJ,Rio de Janeiro, 2007.

Como citar:

Vieira, Daniel Pais Pires; Carvalho, Leandro Lara de; Pereira, Vera Lúcia Patrocinio; "Diastereoselective Multicomponent [4+2]/[3+2] Cycloadditions of gamma-(S)-N,N-dibenzylamine Nitroalkenes Derivatives with Ethyl Vinyl Ether (EVE) and Electron-Poor Alkenes Using Li+- Containing Catalysts.", p-138-138. In: In Blucher Chemistry Proceedings, São Paulo, v. 1, n. 1, Setembro.2013. São Paulo: Blucher, 2013.
ISSN 23184043, DOI 10.5151/chempro-14bmos-R0138-2