PdII insertion-triggered meso-carbon extrusion of N-fused pentaphyrin to form N-fused sapphyrin PdII complexes

meso-Carbon extrusion of N-fused [22]pentaphyrin(1.1.1.1.1) occurred upon its PdII complexation, giving N-fused [22]pentaphyrin (1.1.1.1.0) ([22]sapphyrin) PdII complexes 5 and 6 as 22π aromatic compounds. Oxidation of 5 with DDQ and Sc(OTf)3 gave directly C–N linked dimer 7.