Triphenylphosphine-Catalyzed Simple Synthesis of Dimethyl 1-Aryl-4-ethoxy-5-oxo-4,5-dihydro-1 H -pyrrole-2,3-dicarboxylates |
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| Authors: | Issa Yavari Mansoureh Aghazadeh Mohsen Tafazzoli |
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| Institution: | 1. Department of Chemistry , University of Tarbiat Modarres , Tehran , Iran;2. Department of Chemistry , Sharif University of Technolog , Tehran , Iran |
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| Abstract: | Ethyl 2-arylamino-2-oxo-acetates undergo a complex reaction with dimethyl acetylenedicarboxylate in the presence of triphenylphosphine to produce dimethyl 1-aryl-4-ethoxy-5-oxo-4,5-dihydro-1 H -pyrrole-2,3-dicarboxylates in good yields. Dynamic NMR study of dimethyl 1-(2-methylphenyl)-4-ethoxy-5-oxo-4,5-dihydro-1 H -pyrrole-2,3-dicarboxylate shows a fairly high energy barrier ( j G p = 53.2 kJmol m 1 ) for rotation around the N-aryl single bond, which leads to an observable atropisomerism. |
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| Keywords: | Acetylenic Ester Nh-acid Restricted Rotation Stereochemistry Triphenylphosphine |
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