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Cycloaddition of dibenzoxazepinium ylides to acetylene carboxylates has led to cis-3-aryl-3,13b-dihydrodibenzo[b,f]pyrrolo[1,2-d][1,4]oxazepinecarboxylates, which has dehydrogenated to the corresponding pyrrole derivatives. Stereoselective cycloaddition of dibenzoxazepinium ylides to fullerene [C.sub.60] has given rise to fulleropyrrolidines with cis-configuration and restricted Ph group rotation is seen in the phenyl derivative.

A new approach to porphyrinofullerene donor-acceptor dyads, based on consecutive 1,3-dipolar cycloaddition of azomethine ylides, generated from bis-aziridinedicarboxylate, to C60 and to porphyrin with a maleimidophenyl substituent, was developed. A synthesis of the axially symmetric porphyrin-fullerene-C60 ensemble 5 with a novel rigid pyrrolo[3,4-c]pyrrolic linker was realized. Theoretical, electrochemical, and spectroscopic studies of compound 5 showed that it is capable of forming a charge-separated state. [ABSTRACT FROM AUTHOR]

The synthesis of alkoxycarbonyl-substituted bisa-ziridines with the two aziridine units connected by conjugated p-phenylene, partly conjugated 1,1'-biphenyl-4,4'diyl, and non-conjugated 4,4'-metriylenediphenyI linkers was developed. The reaction of azomethine ylides derived from the bisaziridines with fullerene C60 was optimized and used for the stereoselective preparation of both the monoadducts (C60-linker-aziridine dicarboxylate), and the dumbbell bisadducts (C60-linker-C60). The reasons for the observed selectivity of the azomethine ylide formation and cydoaddition were theoretically studied at the DFT B3LYP/6-31G(d) level or at the ON1OM B3LYP/631G(d):B3LYP/STO-3G level for fullerene-containing molecules. [ABSTRACT FROM AUTHOR]

The diastereospecific and highly site-selective cycloaddition of N-arylazomethine ylides generated in situ from diethyl N-arylaziridine-2,3-dicarboxylates to C 70 fullerene is reported. The reaction provides C 70 fulleropyrrolidines in up to hundreds on a milligram scale as α- and β-adducts in a 4:1 ratio with a controlled stereochemical outcome: cis-aziridines give exclusively trans-adducts, and trans-aziridines give only cis-adducts. The 1 H and 13 C{ 1 H} NMR spectra for different isomeric adducts were recorded and analyzed to identify some characteristic features, which permit an easy identification of isomeric adducts of this type.

The synthesis of alkoxycarbonyl-substituted bisaziridines with the two aziridine units connected by conjugated p-phenylene, partly conjugated 1,1'-biphenyl-4,4'-diyl, and nonconjugated 4,4'-methylenediphenyl linkers was developed. The reaction of azomethine ylides derived from the bisaziridines with fullerene C(60) was optimized and used for the stereoselective preparation of both the monoadducts (C(60)-linker-aziridine dicarboxylate), and the dumbbell bisadducts (C(60)-linker-C(60)). The reasons for the observed selectivity of the azomethine ylide formation and cycloaddition were theoretically studied at the DFT B3LYP/6-31G(d) level or at the ONIOM B3LYP/6-31G(d):B3LYP/STO-3G level for fullerene-containing molecules.