Trimethylsilyl ethers of 1,5-diaryl-3-(trifluoromethyl)-pent-1-en-4-yn-3-oles [Ar-C≡C-C(CF_{3})(OSiMe_{3})-CH═CH-Ar’] in the superacid TfOH give rise to reactive conjugated CF_{3}-allylic-propargylic cations [Ar-C≡C-C^{+}(CF_{3})-CH═CH-Ar’]. These species react with arenes in the presence of 1.5 equiv of TfOH forming regio- and stereoselectively E- 1,1,5-triaryl-3-(trifluoromethyl)-pent-2-en-4-ynes [Ar-C≡C-C(CF_{3})═CH-CHAr'(Ar″)] in good yields. In the excess of TfOH, these CF_{3}-pentenynes are further intramolecularly cyclized into CF_{3}-bicyclic dihydroanthracene derivatives (“helicopter”-like molecules). The CF_{3}-pentenynes may also react with arenes, as external nucleophiles, leading to CF_{3}-indenes. These two main reaction pathways depend on internal nucleophilicity of aryl substituents in CF_{3}-pentenynes and external nucleophilicity of aromatic molecules. Plausible cationic reaction mechanisms have been discussed. CF_{3}-bicyclic dihydroanthracene derivatives have been studied regarding their cytotoxicity and virus-inhibiting activity against influenza virus A/Puerto Rico/8/34 (H1N1) in MDCK cell line.
TfOH-Promoted Reactions of TMS-Ethers of CF3-Pentenynoles with Arenes. Synthesis of CF3-Substituted Pentenynes, Indenes, and Other Carbocyclic Structures
[Category] 신종인플루엔자,
[Source] pubmed
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