Synthetic and Theoretical Studies on the Reduction of Electron Withdrawing Group Conjugated Olefins Using the Hantzsch 1,4-Dihydropyridine Ester
摘要:
The Hantzsch 1,4-dihydropyridine ester (1) has been observed to be a useful selective reducing agent for the reduction of electron-withdrawing conjugated double bonds. The rate of this reaction was observed to be dependent upon the nature of the conjugated substituents and, consequently, the electronic nature of the unsaturated double bond. Theoretical calculations confirmed the importance of the HOMO-LUMO gap for this reaction and implicated a hydride transfer, agreeing with the experimentally observed reaction rate order. The calculations also revealed the importance of a boatlike structure of the 1,4-dihydropyridine nucleus as well as a trans arrangement of the ester groups to facilitate the hydride transfer.
Copper-catalyzed hydroboration of alkenyl oxindoles
作者:Maria Eduarda Contreira、Diogo S. Lüdtke、Angélica V. Moro
DOI:10.1016/j.tetlet.2018.06.009
日期:2018.7
Herein we describe the NHC-Cu(I)-catalyzed hydroboration of alkenyl oxindoles. The corresponding boronates were obtained in good yields, under operationally simple and environmentally friendly conditions, using ethanol as the solvent. Our studies revealed that water-based systems were not very effective. Furthermore, the obtained products are amenable to further elaboration and can be useful to the
Synthetic and Theoretical Studies on the Reduction of Electron Withdrawing Group Conjugated Olefins Using the Hantzsch 1,4-Dihydropyridine Ester
作者:Simon J. Garden、Cristiano Ruch Werneck Guimarães、Marilza B. Corréa、César Augusto Fernandes de Oliveira、Angelo da Cunha Pinto、Ricardo Bicca de Alencastro
DOI:10.1021/jo034921e
日期:2003.11.1
The Hantzsch 1,4-dihydropyridine ester (1) has been observed to be a useful selective reducing agent for the reduction of electron-withdrawing conjugated double bonds. The rate of this reaction was observed to be dependent upon the nature of the conjugated substituents and, consequently, the electronic nature of the unsaturated double bond. Theoretical calculations confirmed the importance of the HOMO-LUMO gap for this reaction and implicated a hydride transfer, agreeing with the experimentally observed reaction rate order. The calculations also revealed the importance of a boatlike structure of the 1,4-dihydropyridine nucleus as well as a trans arrangement of the ester groups to facilitate the hydride transfer.
Bioreduction of the C C double bond with Pseudomonas monteilii ZMU-T17: one approach to 3-monosubstituted oxindoles
An efficient whole cell-mediated bioreduction of 3-methylene-2-oxindoles has been developed, affording a range of 3-monosubstituted oxindoles in moderate to good yields (41-82%) with Pseudomonas monteilii ZMU-T17 as biocatalyst. Additionally, a possible reaction pathway for this bioreduction of C=C double bond was proposed. (C) 2016 Elsevier Ltd. All rights reserved.
728. Hydroxytryptamines. Part IV. Synthesis and reactions of 2-3′-oxindolylethylamines