Piperazine Bridged Thianorrole Dimer

Abstract

Oxidative cyclization of open chain thiabilanes yielded the first examples of unique piperazine bridged thianorrole dimers instead of the expected thianorrole monomer. In the thianorrole dimer, the two thianorrole monomeric units are linked via two direct pyrrole C–C bonds by involving the inverted pyrrole and adjacent pyrrole rings of each thianorrole macrocycle and generate a six-membered piperazine ring that bridges the two thianorrole macrocycles. The spectral studies indicated that the thianorrole dimers are nonaromatic in nature.

One Pot Synthesis of Two Distinct Macrocycles: Aromatic p‐Benzihexaphyrin and Nonaromatic Doubly Fused p‐Benzihexaphyrin

“…The aromatic trithia p ‐benzihexaphyrins 4 – 6 and nonaromatic doubly N‐fused trithia p ‐benzihexaphyrins 7 – 9 were prepared by adopting the 4+2 condensation method as shown in Scheme 1. The appropriate unsymmetrical p ‐benzi thiophene‐based tetrapyrrane precursor 12 was prepared in a sequence of two steps, starting with the previously synthesized (4‐(thiophen‐2‐yl)phenyl)( p ‐tolyl)methanol (mono‐carbinol) 10 by following the reported method [27] (Scheme 1).…”

Structural isomers of di-p-benzidithiaoctaphyrins

“…[7][8][9][10][11][12][13][14] The benzene ring can be incorporated in the porphyrinoid macrocyclic framework via 1,3-linking (m-benziporphyrinoids) or 1,4-linking ( p-benziporphyrinoids). [15][16][17] Over the years, studies have revealed that the m-phenylene ring in m-benziporphyrinoids is generally not involved in the π-conjugation with the rest of the macrocyclic conjugation and hinders the π-delocalization in the macrocyclic core; thereby, the macrocycles normally exhibit non-aromatic features. [18][19][20] On the other hand, the p-phenylene ring in p-benziporphyrinoids generally participates in π-delocalization with the rest of the macrocycle and the p-benziporphyrinoids exhibit characteristics ranging from nonaromatic to aromatic, and in some cases, antiaromatic, characteristic features.…”