Porphyrinatonickel(II)-Cyclopentene and Porphyrinatonickel(II)-Cyclopentadiene Hybrids: Zirconacyclopentadiene-Mediated Syntheses, Structures, and Mechanistic Study.

The reaction of meso- formyl Ni(II) porphyrin 1 with zirconacyclopentadiene 2 in the presence of AlCl 3 afforded four products 3 , 4 , 5 , and 6 with a total yield of over 85%. The structures of these compounds are well-characterized by 1 H NMR an d 13 C NMR spectroscopy, HRMS, and X-ray single-crystal diffraction. The mechanism is proposed mainly on the basis of isotopic labeling experiments, which showed that a Friedel-Crafts-type reaction and β-H shift may be critical during the formation of 5 and 6 .