Polar Diels-Alder reactions

A DFT study of the polar Diels-Alder reaction of 4-aza-6-nitrobenzofuroxan with cyclopentadiene found only one highly asynchronous transition state structure associated with the formation of the 4 + 2-adduct.178 4-Nitrobenzodifuroxan has been shown to be a highly reactive nitroalkene in Diels-Alder reactions with common dienes (cyclopentadiene) to produce stable NED adducts and with ethyl vinyl ether to produce IED adducts.179 Unlike a-acylfuran, 2-nitrofurans have been shown to be active dienophiles in thermal NED Diels-Alder reactions with a variety of buta-1,3-dienes, including Danishefsky s diene.180... 

A DFT study, involving M05-2X and B3LYP functionals, has been used to investigate the catalytic effect of water on the intramolecular polar Diels-Alder reaction of benzo-quinone in the synthesis of the diterpenoid, Elisabethin A. The addition of LiCl to the... 

Ionic Liquids in Polar Diels-Alder Reactions Using Carbocycles and Heterocycles as Dienophiles... 

Cancian, S., Kneeteman, M., Mancini, P.M.E. (2010). Nitroquinolines as dienophiles in Polar Diels-Alder reactions. Influence of molecular solvent and ionic liquids. 14th International Electronic Conference on Synthetic Organic Chemistry (ECSOC-14), ISSN 0095-2338... 

Dechambenait, P., Ferlay, S., Kyrtsakas, N., Hosseini, M.W. (2010). Amidinium based ionic liquids. New Journal of Chemistry, 34,1184-1194. ISSN 1144-0546 Della Rosa, C., Kneeteman, M., Mancini, P.M.E. (2005). 2-Nitrofurans as dienophiles in Diels-Alder reactions. Tetrahedron Letters, 46, 8711-8714, ISSN 0040-4039 Della Rosa, C., Kneeteman, M., Mancini, P.M.E. (2007). Behavior of selenophenes substituted with the electron withdrawing groups in polar Diels-Alder reactions. Tetrahedron Letters, 48, 7075-7078, ISSN 0040-4039... 

The nature of the asynchronous transition states in polar Diels-Alder reactions has been analyzed by Sustmann and Sicking for reactions of several hydroxybutadienes and aminobutadienes with cyanoethylenes. The transition states... 

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