852244-64-5Relevant academic research and scientific papers
Investigation of the scope of a new route to ABCD-bilanes and ABCD-porphyrins
Dogutan, Dilek Kiper,Lindsey, Jonathan S.
, p. 6728 - 6742 (2008/12/23)
(Chemical Equation Presented) A new route to bilanes and porphyrins bearing four distinct meso substituents has been studied to elucidate the scope and gain entry to previously inaccessible compounds. The route entails (i) synthesis of a 1-bromo-19-acylbi
Metal complexation of 1-acyldipyrromethanes and porphyrins formed therefrom
-
Page/Page column 7; 8; 17, (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.
Rational Syntheses of Porphyrins Bearing up to Four Different Meso Substituents
Rao, Polisetti Dharma,Dhanalekshmi, Savithri,Littler, Benjamin J.,Lindsey, Jonathan S.
, p. 7323 - 7344 (2007/10/03)
Porphyrins bearing specific patterns of substituents are crucial building blocks in biomimetic and materials chemistry. We have developed methodology that avoids statistical reactions, employs minimal chromatography, and affords up to gram quantities of regioisomerically pure porphyrins bearing predesignated patterns of up to four different meso substituents. The methodology is based upon the availability of multigram quantities of dipyrromethanes. A procedure for the diacylation of dipyrromethanes using EtMgBr and an acid chloride has been refined. A new procedure for the preparation of unsymmetrical diacyl dipyrromethanes has been developed that involves (1) monoacylation with EtMgBr and a pyridyl benzothioate followed by (2) introduction of the second acyl unit upon reaction with EtMgBr and an acid chloride. The scope of these acylation methods has been examined by preparing multigram quantities of diacyl dipyrromethanes bearing a variety of substituents. Reduction of the diacyl dipyrromethane to the corresponding dipyrromethane-dicarbinol is achieved with NaBH4 in methanolic THF. Porphyrin formation involves the acid-catalyzed condensation of a dipyrromethane-dicarbinol and a dipyrromethane followed by oxidation with DDQ. Optimal conditions for the condensation were identified after examining various reaction parameters (solvent, temperature, acid, concentration, time). The conditions identified (2.5 mM reactants in acetonitrile containing 30 mM TFA at room temperature for 3B, trans-A2B2, trans-AB2C, cis-A2B2, cis-A2BC, and ABCD were prepared, including >1-g quantities of three porphyrins.
