Stanisław Ostrowski

A new approach to the synthesis of porphyrin-fullerene dyads.

A new synthetic approach to porphyrin-fullerene dyads utilizing tetraphenylporphyrin (TPP) and three novel reactions (vicarious nucleophilic substitution, metathesis, and [4+2]-cycloaddition to fullerene) is described. 5-(4-Nitrophenyl)-10,15,20-triphenylporphyrin zinc complex reacts with the carbanion of chloromethyl para-tolyl sulphone (which bears a leaving group Cl at the carbanionic center),affording the nucleophilic substitution of hydrogen product containing a CH2SO2Tol group. The product obtained when alkylated with an alkyl halide (bearing an acetylenic function in the terminal position), followed by the cross-enyne metathesis reaction (with the use of an efficient ruthenium catalyst), resulted in the formation of a TPP-diene building block. Its Diels-Alder reaction with C60-fullerene led to the title dyad – a new artificial photosynthetic model. This method opens up the possibility for synthesis of dyads with variable distances between chromophores, depending on the type of the alkyl halides used.

Synthesis of some β-nitro-meso-tetraphenylporphyrin derivatives

A selective electrophilic nitration of meso-tetraarylporphyrin copper(II) and nickel(II) complexes, bearing in meso-aryl rings a variety of substituents (3-NO2, 3-CH3, 3-Cl, 2,3,4,5,6-pentafluoro-, and 2,6-dichloro-), is described. The reactions of the above porphyrinates, carried out in CHCl3 at room temperature, with aqueous HNO3 (concentration 15-50%), resulted in the formation of the respective mono-β-nitrated products, in good or very good yield (74-93%). All the synthesized compounds were demetallated in CF3CO2H/H2SO4 mixture to give β-nitro-substituted porphyrin free bases – very versatile substrates for further chemical transformations.

Preparation of meso -Tetraarylporphyrins Nitrated in Two Neighboring Aromatic Rings

Abstract Selective nitration of tetraphenylporphyrin (TPP) and its derivatives is reported. The reaction of meso-aryl substituted porphyrins with fuming yellow nitric acid (d = 1.53) at the temperature 0–20°C results in the formation of 5,10-bis(4-nitroaryl)-15,20-diarylporphyrins with yields of 30–83%.

Nucleophilic substitution of hydrogen in meso-nitroaryl-substituted porphyrins—unprotected at the NH-centers in the core ring

Abstract Unprotected 5-(4-nitrophenyl)-10,15,20-triphenylporphyrin and 5,10-bis(4-nitrophenyl)-15,20-diphenylporphyrin react in the presence of a base at low temperature with carbanions (which bear a leaving group X at the carbanionic center) affording vicarious nucleophilic substitution of hydrogen (VNS) products in good yields (50–89%). The reactivity is explained in terms of the predominance of the porphyrin N -anion resonance forms at this temperature.

Synthesis of meso-TPP Revisited: Its “Green-Oriented” Optimization Under Controlled Microwave Heating

Abstract A practical and proecological improvement for synthesis of meso-tetraphenylporphyrin (meso-TPP) under microwave irradiation is described. A cyclocondensation reaction of benzaldehyde and pyrrole followed by oxidation of the porphyrinogen formed as an intermediate in a small amount of propionic acid at 120 °C (under controlled microwave heating) resulted in conversion to meso-TPP in a reasonable yield (ca. 30%) in preparative-scale experiments (300–500 mg). The influence of many parameters such as the concentration of reagents, catalyst, solvent, temperature, reaction time, and oxidant on the reaction yield was studied. The environmental motive in this improvement is reduction of solvent volume (ca. 250 times). Also, some toxic reagents were eliminated from the procedure.

The synthesis of sugar-decorated hydrophilic porphyrins

The synthesis of porphyrins conjugated with sugar moieties is described. meso-Aminophenyl-substituted and β-amino-substituted porphyrin derivatives reacted with benzyl protected glucuronic acid leading to gluco-conjugated hybrids, which after reductive deprotection of OH groups (H2, 10% Pd/C) gave the desired target products of increased hydrophilicity. Alternatively, this type of similar conjugates were obtained through SNAr reaction of meso-tetrakis(pentafluorophenyl)porphyrin with aminomethyl sacharides. The substitution took place selectively in para-position of meso-perfluorophenyl rings, thus giving rise to one, two, or three times substituted products carrying N-linked glucoside residues.

5-{4-itro-3-[1-(toluene-4-sulphonyl)-hexyl]-phenyl}-10,15,20-triphenylporphyrin Zinc(II)

As part of ongoing research programme we synthesised the title meso-tetraarylporphyrin derivative possessing a high degree of complexity in one phenyl ring.[...]

A fast and convenient method for analysis of collagen hydrolysis products Szybka i dogodna metoda analizy produktów hydrolizy kolagenu

Polypeptides produced by hydrolysis of collagen from minced animal hide and skin scraps were studied by mass spectrometry (MS) in conjunction with electrophoresis to det. their mol. mass. The degree of peptides ionisation was ca 50+. This allowed for observation of the large polypeptide chains with mass analyzers with a relatively low m/z range. The electrospray and atm. pressure photoionization techniques were used. The polypeptide fractions formed during the hydrolysis of collagen were easily identified. The mol. mass of the products was 28–82 kDa. Zaproponowano i zweryfikowano szybką i dogodną metode analizy polipeptydow wytwarzanych przez hydrolize kolagenu, ktorego źrodlem byly rozdrobnione skorki zwierzece. Badania metodą spektrometrii mas (MS), wspomagane danymi z rozdzialu elektroforetycznego, pozwolily stwierdzic, ze cząsteczki polipeptydow jonizują sie ok. 50-krotnie. Stosując techniki electrospray (ESI) i fotojonizacje pod ciśnieniem atmosferycznym (APPI), opracowano sposob identyfikacji frakcji peptydowych zarowno w trakcie hydrolizy, jak rowniez w gotowym produkcie. Znaleziono frakcje o masie cząsteczkowej 28–82 kDa. Wysoki stopien zjonizowania umozliwia obserwacje duzych cząsteczek z wykorzystaniem aparatow o stosunkowo niewielkim zakresie pomiaru masy (m/z), co jest niewątpliwą zaletą metody i czyni ją ogolnodostepną.

Synthesis of lutetium(III)–porphyrin complexes: old problems and new excellent conditions found

A convenient method for the preparation of very attractive and almost unknown lutetium(III)–porphyrins was developed. Systematic investigations involving a broad spectrum of solvents (DMF, TCB, imidazole, sulfolane, and a CHCl3/MeOH mixture), as well as studies concerning the influence of temperature and the reaction time on the yield, were performed. Under the optimized experimental conditions found within the study for [5,10,15,20-tetraphenylporphyrinato]lutetium(III) chloride (sulfolane, reflux, 0.5 h; 88% yield), the synthesis of some other more complex derivatives was demonstrated.

The First Example of Oxidative Nucleophilic Substitution of Hydrogen in meso-Aryl Ring of the 5,10,15,20-Tetraphenylporphyrin Derivatives

A synthesis of [2-nitro-5-(10,15,20-triphenylporphyrin-5-yl)-phenyl]phenyl-acetonitrile zinc complex by the reaction of the respective nitroporphyrin with the anion of benzyl cyanide, followed by addition of DDQ, is described. This is the first example of this type of process in the nitrophenyl side ring of meso-tetraarylporphyrin derivatives.