During our initial work on the synthesis of the cyclic porphyrin hexamer c -P6 t Bu, by palladium-catalyzed oxidative coupling of the linear porphyrin monomer l -P1 t Bu or dimer l -P2 t Bu in the presence of the hexapyridyl template T6 (Scheme 1 a), we noticed the formation of a high-mass byproduct, which was identified as the 12-porphyrin nanoring figure-of-eight complex c -P12 t Bu ⋅ ( T6 ) 2 .[ 9b, c ] Analytical gel permeation chromatography (GPC) analysis of crude reaction mixtures (Figure 1 a ,b) indicated that c -P12 t Bu ⋅ ( T6 ) 2 was formed in yields of 9 and 12 % from l -P1 t Bu and l -P2 t Bu, respectively.
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