Ring-opening metathesis polymer sphere-supported seco-porphyrazines: efficient and recyclable photooxygenation catalysts.

[reaction: see text] Crossover Linstead macrocyclization of norbornenyl-tagged diaminomaleonitrile with dipropylmaleonitrile gave the corresponding magnesium diaminohexapropylporphyrazine, which was subsequently converted into its zinc seco-derivative. Polymerization gave the corresponding ROMPgel and ROMPsphere (ROMP = ring-opening metathesis polymer) reagents, the latter of which proved efficient as an immobilized catalyst for the sensitized production of singlet oxygen for the purification-minimized parallel synthesis of endoperoxides and ene adducts.