کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5226556 1383579 2009 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Microwave-assisted reactions of nitroheterocycles with dienes. Diels-Alder and tandem hetero Diels-Alder/[3,3] sigmatropic shift
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Microwave-assisted reactions of nitroheterocycles with dienes. Diels-Alder and tandem hetero Diels-Alder/[3,3] sigmatropic shift
چکیده انگلیسی

Diels-Alder cycloaddition of 3-nitro-1-(p-toluenesulfonyl)indole 1 with dienes 2-6 under microwave irradiation in solvent-free conditions gave carbazole derivatives after elimination of the nitro group and in situ aromatization. While 3-nitro-1-(p-toluenesulfonyl)pyrrole 11 afforded indole derivatives, 4-nitro-1-(p-toluenesulfonyl)pyrazole 13 with cyclohexadiene 2 did not afford the expected cycloadduct but instead gave 1-cyclohexen-2-ylpyrazole 16. This process occurred by hydrolysis of the 1-(p-toluenesulfonyl) group, protonation of the diene and nucleophilic addition of the pyrazolate ion, as elucidated by computational studies. Reaction of nitroindole 1 with cyclohexadiene 2 afforded exclusively the endo stereoisomer (10endo) in a tandem hetero Diels-Alder/[3,3] sigmatropic shift, as determined by computational calculations.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Tetrahedron - Volume 65, Issue 27, 4 July 2009, Pages 5328-5336
نویسندگان
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