3 Porphyrins: Syntheses and Properties
61
Fig. 3.13 Template-directed synthesis of π-conjugated cyclohexamer of Zn porphyrin
Fig. 3.14 Template-directed synthesis of π-conjugated cyclooligomers of Zn porphyrin
of the cyclododecamer was formed as a byproduct in these cyclization reactions,
the Glacer reaction of the butadiyne-linked linear tetramer 34 in the presence
of T 6 as a mismatch combination for the cyclo-(32) 6 generated, in 39% yield,
a cyclic porphyrin dodecamer cyclo-(34) 3 that includes two template molecules
inside the cavity (Kondratuk et al. 2014). A smaller hexapyridine template T’ 6
having a hexaethynylbenzene core instead of the hexaphenylbenzene core of the T 6
template was used in the cyclization of ethyne-linked linear oligomers of porphyrin
(Rickhaus et al. 2017). The linear ethyne-linked porphyrin hexamer 35 was subjected
to Sonogashira coupling reaction to give a 1:1 complex, cyclo-35•T’ 6 , in 15% yield.
A tetrapyridine template T’ 4 has a tetraethynylbenzene core and worked well in
61
Fig. 3.13 Template-directed synthesis of π-conjugated cyclohexamer of Zn porphyrin
Fig. 3.14 Template-directed synthesis of π-conjugated cyclooligomers of Zn porphyrin
of the cyclododecamer was formed as a byproduct in these cyclization reactions,
the Glacer reaction of the butadiyne-linked linear tetramer 34 in the presence
of T 6 as a mismatch combination for the cyclo-(32) 6 generated, in 39% yield,
a cyclic porphyrin dodecamer cyclo-(34) 3 that includes two template molecules
inside the cavity (Kondratuk et al. 2014). A smaller hexapyridine template T’ 6
having a hexaethynylbenzene core instead of the hexaphenylbenzene core of the T 6
template was used in the cyclization of ethyne-linked linear oligomers of porphyrin
(Rickhaus et al. 2017). The linear ethyne-linked porphyrin hexamer 35 was subjected
to Sonogashira coupling reaction to give a 1:1 complex, cyclo-35•T’ 6 , in 15% yield.
A tetrapyridine template T’ 4 has a tetraethynylbenzene core and worked well in