Diels-Alder Reaction Fullerene with 1,3-butadiene

Diels-Alder reactions of butadienes 13 and 2,3-di-w-propylbutadiene 14 with [60]-fullerene 15 led to several fullerene derivatives [15-17] (Scheme 2.10). Dienes 13 and 14 bore electron-donating groups, but the reactions also occurred with electron-withdrawing substituents due to the sufficiently low-energy LUMO of Ceo-... 

Exohedral functionalization of [60]-fullerene by [4 -i- 2] cycloadditions. Diels-Alder reactions of [60]-fullerene with electron-rich 2,3-dioxysubstituted-1,3-butadienes [146]... 

Recently, the reaction of masked ortho-benzoquinone [92] with C60 was tested [93]. The [4+2] cycloaddition reaction of such electron-deficient dienes with fullerenes resulted in the formation of highly functionalized bicyclo [2.2.2] octenone-fused fullerenes. The reactants were generated in situ by the oxidation of the readily available 2-methoxy phenols with hypervalent iodine agents. For the several different masked ortho-benzoquinones that were tested, it was found that the yield of the cycloadducts depends on the nature of the starting materials and the reaction conditions. Other Diels-Alder reactions of such electron-deficient dienes with electron-poor fullerenes involved tropones [94], 1,3-butadienes substituted with electron-withdrawing groups [95], and 2-pyrone [96]. 

Nitropyridine and 4-nitropyridine A-oxide have been shown to react with iso-prene, 1-methoxy-l,3-butadiene, and Danishefsky s diene to produce isoquinoline cycloadducts. One asymmetric and asynchronous transition state (TS) was detected between the reactants and the cycloadduct with isoprene and two TS were observed when 1-methoxy-l,3-butadiene and Danishefsky s diene were used. The Diels-Alder reaction of highly substituted dihydropyridines with e-deficient alkenes produced highly substituted isoquinuclidines with high stereo- and regio-selectivity. The Diels-Alder cycloaddition of cyclopentadiene to lithium ion encapsulated [60]fullerene proceeds at a higher rate than with that of empty [60]fullerene. ... 

The [4 -I- 2] cycloadditions have been used to synthesize fullerene multiadducts in the past. A sixfold Diels-Alder product has been reported not only by the reaction of an excess of 2,3-dimethyl-1,3-butadiene with Cgo, but also by different bisadducts connected crown ethers to the fullerene spheroid. The properties of these derivatives have been studied for several potential applications, such as molecular sensors and complexation chemistry. 

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