852244-63-4Relevant academic research and scientific papers
Metal complexation of 1-acyldipyrromethanes and porphyrins formed therefrom
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Page/Page column 18, (2008/06/13)
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.
Direct synthesis of palladium porphyrins from acyldipyrromethanes
Sharada, Duddu S.,Muresan, Ana Z.,Muthukumaran, Kannan,Lindsey, Jonathan S.
, p. 3500 - 3510 (2007/10/03)
(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.
