852244-84-9Relevant academic research and scientific papers
Direct synthesis of palladium porphyrins from acyldipyrromethanes
Sharada, Duddu S.,Muresan, Ana Z.,Muthukumaran, Kannan,Lindsey, Jonathan S.
, p. 3500 - 3510 (2005)
(Chemical Equation Presented) Palladium porphyrins are valuable photosensitizers and luminescent agents in biology and materials chemistry. New methodology is described wherein a 1-acyldipyrromethane is converted into the palladium chelate of a trans-A2B2 porphyrin via a one-flask reaction. The reaction entails self-condensation of the 1-acyldipyrromethane in refluxing ethanol containing KOH (5-10 mol equiv) and Pd(CH3CN)2Cl2 (0.6 mol equiv) exposed to air. This direct route to palladium porphyrins is more expedient than the four steps of the traditional synthesis: (1) reduction of the 1-acyldipyrromethane; (2) acid-catalyzed condensation; (3) oxidation of the porphyrinogen intermediate; and (4) metal insertion. The new synthesis requires neither acid nor DDQ and formally entails only a 2e- + 2H+ oxidation overall versus the traditional multistep synthesis which requires a 2e- + 2H + reduction per each 1-acyldipyrromethane (4e- + 4H + overall) followed by a 6e- + 6H+ oxidation. The analogous reaction of a 1,9-diacyldipyrromethane and a dipyrromethane also gives the palladium porphyrin. Seven palladium porphyrins have been prepared in yields of 25-57%. The direct route also can be used with Cu(OAc) 2·H2O to give the copper porphyrin albeit in low yield. In summary, this methodology readily affords palladium porphyrins directly from acyldipyrromethanes.
Metal complexation of 1-acyldipyrromethanes and porphyrins formed therefrom
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A first aspect of the invention is a method of making a porphyrin-metal complex, comprising: (a) providing a first reagent selected from the group consisting of 1-acyldipyrromethanes, 1-acyldipyrrins, dipyrromethane-1-carbinols 1,9-diacyldipyrromethanes and 1,9-diacyldipyrrins; and then (b) condensing the first reagent with either itself (in the case of 1-acyldipyrromethanes, 1-acyldipyrrins, and dipyrromethane-1-carbinols) or a dipyrromethane (in the case of 1,9-diacyldipyrromethanes and 1,9-diacyldipyrrins) in a reaction mixture comprising a solvent and a second reagent selected from the group consisting of palladium and copper complexes to produce the porphyrin-metal complex (with the metal being palladium or copper). In preferred embodiments of the foregoing, the reaction mixture further comprises a base such as KOH or NaH.
