Publication Date:
2011-03-24
Description:
In spite of diversified electrophilicity of E-2-arylnitroethenes, their [4 + 2] cycloaddition reactions with cyclopentadiene leads to the corresponding 6- endo -aryl-5- exo -nitronorbornenes and 6- exo -aryl-5- endo -nitronorbornenes as the only reaction products. Stereoselectivity, substituent and solvent effects, and activation parameters, suggest that these reactions occur via a synchronous concerted mechanism on both competing pathways. The experimental results obtained are consistent with the data from B3LYP/6-31G(d) calculations. Due to high electrophilicity of E-2-arylnitroethenes, the reactions studied should be considered as polar [4 + 2] cycloadditions. Copyright © 2011 John Wiley & Sons, Ltd. In spite of diversified electrophilicity of E-2-arylnitroethenes, their [4+2] cycloaddition reactions with cyclopentadiene leads to the corresponding 6-endo-aryl-5-exo-nitronorbornenes and 6-exo-aryl-5-endo-nitronorbornenes as the only reaction products. Stereoselectivity, substituent and solvent effects, and activation parameters, suggest that these reactions occur via a synchronous concerted mechanism on both competing pathways. The experimental results obtained are consistent with the data from B3LYP/6-31G(d) calculations. Due to high electrophilicity of E-2-arylnitroethenes, the reactions studied should be considered as polar [4+2] cycloadditions.
Print ISSN:
0894-3230
Electronic ISSN:
1099-1395
Topics:
Chemistry and Pharmacology
,
Physics
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