Synthesis of heterocycle-linked [60]fullerene derivatives by heterocyclic o-quinodimethane Diels-Alder reaction and self-sensitized photooxygenation of the cycloadducts
[60]Fullerene underwent [4+2]cycloaddition reaction smoothly with heteroaromatic analogs of o-quinodimethanes including furan, thiophene, oxazole, thiazole, indole and quinoxaline to give the corresponding heterocycle-linked [60]fullerenes. Among them, the furan and oxazole derivatives were prepared with all equipments covered with an aluminum foil, because of lability to oxygen under exposure to room
Asymmetric inverse-electron-demand 1,3-dipolar cycloadditions of cyclopentadienones and thiophene-1,1-dioxide with <i>C</i>,<i>N</i>-cyclic azomethine imines
The normal 1,3-dipolarcycloaddition between the carbonates of 4-hydroxy-2-cyclopentenones and C,N-cyclicazomethineimines can be switched to an inverse-electron-demand version under Pd(0) catalysis, by in situ generation of HOMO-raised η2-Pd(0)-cyclopentadienone complexes. An array of fused heterocyclic architectures are constructed with high levels of diastereo and enantioselectivity, and diastereodivergent