Enantiomerically Pure “Winged” Spirane Porphyrazinoctaols

Abstract

Herein we report the first synthesis of porphyrazinoctaol derivatives-the enantiomerically pure, "winged" spirane porphyrazines-through the use of a simple, reliable strategy based on the Ley dispoke protection procedure. ['] We earlier described the synthesis of porphyrazinoctathiol derivatives by macrocyclization of 2,3-bis(benzylthio)maleonitrile with magnesium propoxide in propanol,121 their transmetalation, and reductive deben~ylation.[~] The octathiol thus obtained exhibited diverse coordination chemistry. Complexes were isolated with four metal cations peripherally bonded to the eight thiolate residues by either bidentate (S-S) or tridentate (S-meso-N-S) coordination, in addition to internal metal-ion complexation. These star porphyrazines readily lend themselves to the study of indirect metal-metal interactions through the porphyrazine 7~ system and are unique in that the binding mode may be selected at will. We subsequently reported the synthesis and characterization of various porphyrazinoctamine derivatives as well as the formation of charge-transfer complexes with tetracyanoquinodimethane (TCNQ) and C,, stereochemical outcome of the reaction under thermodynamic conditions, which gives rise to only one diastereoisomer of 2.". The chirality inherent in the tartrate induces sterogenicity at the ketal centers and results in a product in which the methoxycarbonyl moieties are equatorial. Monoiodination, followed by base-mediated anti-dehydroiodination, afforded chiral alkene 3 (53 %). Amide formation and dehydration proceeded smoothly to give dinitrile 4 in 77 O/O overall yield. A solution of 4 and magnesium propoxide in propanol under reflux provided the magnesium porphyrazine 5 in 45% yield. Strong acids such as trifluoroacetic acid rapidly demetalated 5 ; unfortunately these conditions also caused degradation of the macrocycle. However, reaction with glacial acetic acid resulted in clean demetalation without epimerization and production of the D,-symmetric, enantiomerically pure porphyrazine 6 (Scheme 2).

Functional solitare- and trans-hybrids, the synthesis, characterization, electrochemistry and reactivity of porphyrazine/phthalocyanine hybrids bearing nitro and amino functionality

“…The rf value H 2 [Pz(n-Pr) 6 (BzNO 2 )], (4a) on thin layer choromatography (TLC) (silica gel / chloroform:hexane) were higher than that of H 2 [Pz(n-Pr) 4 (BzNO 2 ) 2 ], (4b). In other words, the greater the disparity in polarity of the peripheral substituents on the Pz/Pc hybrid macrocycles is, the better the chromatographic separation of two Pz/Pc hybrids is achieved [14,26,30,31]. Thin-layer chromatography shows that crude product contain reproducible both solitare-and trans-Pz/Pc hybrid (4a and 4b) as well as very little amounts of other unsymmetrical and symmmetrical by products.…”

Novel porphyrazines containing peripherally functionalized macrocyclic (N2O2, N2S2) units: Synthesis and characterization

“…In the UV-vis spectra of porphyrazines (10, 11) containing peripheral nitrogen atoms, the disappearance of n / p * absorbance and a sharpening of the Q band indicate metal coordination to the peripheral nitrogen atoms. Because the nitrogen n electrons are no longer available to the porphyrazine p-system, metal coordination to the peripheral nitrogen atoms ultimately results in a spectrum that resembles an unsubstituted porphyrazine or phthalocyanine [12,15,45]. Aggregation of symmetrical porphyrazine and phthalocyanines can be efficiently followed from band broadening to a blue shift of the Q bands.…”

Synthesis, characterization and computational investigation of novel metalloporphyrazines containing 15-membered O2S2-donor macrocyclic moieties

“…9. ORTEP3 [3] drawing of the title compound with the atomnumbering Scheme (Displacement ellipsoids are drawn at the 50% probability level) s*(N54-C58), s*(N54-C59) and s*(N56-C172) respectively, have 14,96 kcal/mol and 14.97 kcal/mol strong stabilization energies. Also, in the s*(C8-N56), s*(N53-C57), s*(C5-N53), s*(C34-N55), s*(N54-C58), s*(N54-C59) and s*(N56-C172) bonds hybrid of the C and N atoms and bonds gain 23.96% in s character 75.94% in p character (with hybrid orbital sp 3.17 ).…”

“…Porphyr azines are similar to phthalocyanines, so they can also be used in similar applications. In contrast, the similarities among porphyrazines and their derivatives such as aminoporphyrazines, porphyrazinols and porphyrazine thiolates have been less studied since their first synthesis, which took place almost 60 years ago [2][3][4]. Porphyrazines have found vast applications in diverse areas such as industrial dyes and pigments, electrocatalysts, electrochromic displays, PDT applica tions, chemical sensors, Langmuir-Blodgett films, liquid crystals and nonlinear optics, including their application in material science [5][6][7].…”