在含有微量水的 MeCN 中,在Et 3 N 存在下,分子碘介导的 3-乙酰基-2 H -chromen -2-ones、β-溴代-β-硝基苯乙烯和吡啶合成角氧杂三嗪核心是发达。该反应通过 2-oxo-2-(2-oxo-2 H -chromen-3-yl)-1-(pyridin-1-ium-1-yl)ethan-1-ide 与溴硝基苯乙烯的分子间迈克尔反应进行通过分子内迈克尔反应和消除步骤。典型产品的立体化学证据来自单晶 X 射线分析。该策略的重要特征是它形成了三个具有良好选择性的立体中心。
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
Strategies towards potent trypanocidal drugs: Application of Rh-catalyzed [2 + 2 + 2] cycloadditions, sulfonyl phthalide annulation and nitroalkene reactions for the synthesis of substituted quinones and their evaluation against Trypanosoma cruzi
作者:James M. Wood、Nishikant S. Satam、Renata G. Almeida、Vinicius S. Cristani、Dênis P. de Lima、Luiza Dantas-Pereira、Kelly Salomão、Rubem F.S. Menna-Barreto、Irishi N.N. Namboothiri、John F. Bower、Eufrânio N. da Silva Júnior
DOI:10.1016/j.bmc.2020.115565
日期:2020.8
Rhodium-catalyzed [2 + 2 + 2] cycloadditions, sulfonyl phthalideannulations and nitroalkene reactions have been employed for the synthesis of 56 quinone-based compounds. These were evaluated against Trypanosoma cruzi, the parasite that causes Chagas disease. The reactions described here are part of a program that aims to utilize modern, versatile and efficient synthetic methods for the one or two
Organocatalytic Asymmetric Synthesis of Aza-Spirooxindoles via Michael/Friedel–Crafts Cascade Reaction of 1,3-Nitroenynes and 3-Pyrrolyloxindoles
作者:Qijian Ni、Xuyang Wang、Da Zeng、Qianling Wu、Xiaoxiao Song
DOI:10.1021/acs.orglett.1c00409
日期:2021.3.19
An asymmetric [3+3] cyclization of nitroenynes and 3-pyrrolyloxindoles has been realized with a chiral bifunctional squaramide catalyst. This Michael/Friedel–Crafts cascade strategy provides a facile and efficient access to enantioenriched polycyclic aza-spirooxindoles with 32–95% isolated yields and excellent stereocontrol under mild reaction conditions.
CAN-mediated new, regioselective one-pot access to bicyclic cationic structures with 2,3-dihydro-1H-pyrazolo[1,2-a]pyrazol-4-ium core
作者:Mikhail I. Pleshchev、Nikita V. Das Gupta、Vladimir V. Kuznetsov、Ivan V. Fedyanin、Vadim V. Kachala、Nina N. Makhova
DOI:10.1016/j.tet.2015.09.033
日期:2015.11
[3+2]-cycloaddition of (2-bromo-2-nitrovinyl)arenes to N,N-cyclic azomethine imines, generated in situ by diaziridine ringopening in 6-Ar-1,5-diazabicyclo[3.1.0]hexanes or by metathesis of initially formed azomethine imine, followed by one-pot aromatization of the formed pyrazolidine ring.
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