Quinonoid compounds via reactions of lawsone and 2-aminonaphthoquinone with α-bromonitroalkenes and nitroallylic acetates: Structural diversity by C-ring modification and cytotoxic evaluation against cancer cells
作者:Thekke V. Baiju、Renata G. Almeida、Sudheesh T. Sivanandan、Carlos A. de Simone、Lucas M. Brito、Bruno C. Cavalcanti、Claudia Pessoa、Irishi N.N. Namboothiri、Eufrânio N. da Silva Júnior
DOI:10.1016/j.ejmech.2018.03.079
日期:2018.5
Morita-Baylis-Hillmanacetates and α-bromonitroalkenes have been employed in cascade reactions with lawsone and 2-aminonaphthoquinone for the one-pot synthesis of heterocycle fused quinonoid compounds. The reactions reported here utilized the 1,3-binucleophilic potential of hydroxy- and aminonaphthoquinones and the 1,2/1,3-bielectrophilic potential of bromonitroalkenes and Morita-Baylis-Hillman acetates
Phosphonylpyrazoles from Bestmann−Ohira Reagent and Nitroalkenes: Synthesis and Dynamic NMR Studies
作者:Rajendran Muruganantham、Irishi Namboothiri
DOI:10.1021/jo902595e
日期:2010.4.2
also included Morita−Baylis−Hillman adducts of conjugated nitroalkenes with various electrophiles. Detailed dynamicNMRstudies were performed on the prototropic tautomerism exhibited by the phosphonylpyrazoles using CDCl3 and DMSO-d6 as solvents and 1H and 31P as the probe nuclei. These studies unraveled the existence of two tautomers in solution with a small energy difference but considerable barrier
1-重氮-2-氧代丙基膦酸二乙酯(Bestmann-Ohira试剂)作为硝基烯与环加成伙伴的应用已得到广泛研究。Bestmann-Ohira试剂与各种硝基烯烃(例如,碳环或杂环的一部分的β-取代的,α,β-二取代的和硝基乙烯)进行的碱介导反应通过室温下的一锅区域选择性反应提供了官能化的磷酸ny唑。高产。这些反应中使用的取代硝基烯烃还包括共轭硝基烯烃与各种亲电试剂的森田-贝利斯-希尔曼加合物。使用CDCl 3和DMSO- d 6作为溶剂,对膦酰基吡唑显示的质子互变异构进行了详细的动态NMR研究。1 H和31 P作为探针核。这些研究揭示了溶液中两种互变异构体的存在,它们的能量差很小,但对互变具有很大的障碍。
Imidazoles from nitroallylic acetates and α-bromonitroalkenes with amidines: synthesis and trypanocidal activity studies
作者:Elumalai Gopi、Tarun Kumar、Rubem F. S. Menna-Barreto、Wagner O. Valença、Eufrânio N. da Silva Júnior、Irishi N. N. Namboothiri
DOI:10.1039/c5ob01444a
日期:——
Cascade reactions of amidines with nitroallylic acetates and α-bromonitroalkenes provide potentially bioactive imidazoles in good to excellent yields in most cases. While 2,4-disubstituted imidazol-5-yl acetates are formed in the first case, 2,4-disubstituted imidazoles, bearing no substituent at position 5, are the products in the second case. These two series of imidazoles, viz. 2,4,5-trisubstituted
Stereoselective construction of carbocycles and heterocycles via cascade reactions involving curcumins and nitroalkenes
作者:Narasimham Ayyagari、Deena Jose、Shaikh M. Mobin、Irishi N.N. Namboothiri
DOI:10.1016/j.tetlet.2010.11.017
日期:2011.1
The reaction of curcumins with nitroalkenes has been investigated for the first time. Highly functionalized cyclohexanones possessing three contiguous chiral centers with complete diastereoselectivity have been synthesized through an inter-intramolecular double Michael reaction involving curcumin and nitroalkene under extremely simple experimental conditions (K2CO3 in aqueous THF). Under identical conditions, curcumins react with alpha-bromonitroalkenes to afford dihydrofurans through an intermolecular Michael addition-intramolecular nucleophilic substitution (O-alkylation), which is analogous to an 'interrupted' Feist-Benary reaction. These novel transformations of curcumins empower us to expand the repertoire of curcumin based therapeutics. (C) 2010 Elsevier Ltd. All rights reserved.