First example of a covalently bound dimeric inverted porphyrin

Reaction of 5,10,15,20-tetraphenyl-2-aza-21-carbaporphyrinatonickel(II) with dihalomethanes in the presence of a proton scavenger gives a 2,21'-CH2-linked dimer of Ni(II) inverted porphyrins with the yield reaching 90% and its 2,2'-linked isomer as a minor product.