132313-39-4

Upstream product

• 132313-38-3 5-(4-Tolyl)-1-(phenylhydroxymethyl)dipyrromethane 
• 132362-77-7 5-(4-Fluoro-3-methylphenyl)-1-<(4-methoxyphenyl)hydroxymethyl>dipyrromethane 
• 104-87-0 4-methyl-benzaldehyde 
• 107798-98-1 5-phenyldipyrromethane 
• 250695-22-8 1,9-bis[α-hydroxy-α-(p-tolyl)methyl]-5-phenyldipyrromethane 
• 352423-80-4 {5-[phenyl-(1H-pyrrol-2-yl)-methyl]-1H-pyrrol-2-yl}-p-tolyl-methanol 
• 5720-05-8 4-methylphenylboronic acid 
• 1057140-05-2 5,15-dibromo-10,20-diphenylporphyrin 
• 816454-48-5 10-(9-borabicyclo[3.3.1]non-9-yl)-1-(4-methylbenzoyl)-5-phenyldipyrromethane 
• 100-52-7 benzaldehyde 
• 147804-55-5 5-(4-methylphenyl)dipyrromethane 
• 750646-77-6 10-(9-borabicyclo[3.3.1]non-9-yl)-1-(4-methylbenzoyl)-5-phenyldipyrromethane 
• 750646-90-3 10-(dibutylboryl)-1-(4-methylbenzoyl)-5-phenyldipyrromethane 
• 82297-89-0 (4-fluoro-3-methyl)phenylmagnesium bromide 

Relevant academic research and scientific papers

Effects of aldehyde or dipyrromethane substituents on the reaction course leading to meso-substituted porphyrins

To better understand the effects of diverse substituents on reactions leading to porphyrins, pyrrole+aldehyde condensations and related reactions of dipyrromethanes were examined. The course of pyrrole+aldehyde condensations was investigated by monitoring the yield of porphyrin (by UV-Vis spectroscopy), reaction of aldehyde (by TLC), and changes in the composition of oligomers (by laser desorption mass spectrometry). Reaction reversibility was examined via exchange experiments. Reversibility of reactions leading to porphyrin was further probed with studies of dipyrromethanes. The reaction course was found to depend on the nature of the substituent and the acid catalyst. Alkyl or electron-donating substituents displayed levels of reversibility (exchange/scrambling) on par or greater than that of the phenyl substituent, whereas electron-withdrawing or sterically bulky substituents exhibited little to no reversibility. The results obtained provide insight into the electronic and steric effects of different substituents and should facilitate the design of synthetic plans for preparing porphyrinic macrocycles. Graphical abstract.

Investigation of conditions giving minimal scrambling in the synthesis of trans-porphyrins from dipyrromethanes and aldehydes

A diverse range of reaction conditions for the MacDonald-type 2 + 2 condensation of a 5-substituted dipyrromethane and an aldehyde has been studied with the goal of eliminating acid-catalyzed polypyrrolic rearrangement reactions in the synthesis of trans-porphyrins. A rapid screening method based on laser desorption mass spectrometry has enabled the degree of rearrangement to be examined as a function of the acid catalyst, reagent concentration, reagent stoichiometry, solvent, salts, and temperature. For condensations involving 5-mesityldipyrromethane, we identified reaction at 10 mM concentration in CH2Cl2 with 17.8 mM TFA as optimal conditions for suppression of the rearrangement reaction. A synthetic procedure based on these conditions allowed the expedient synthesis of multigram batches of eight trans-porphyrins in 48-14% yield from 5-mesityldipyrromethane, with minimal chromatography. The same conditions were also effective for the synthesis of two trans-porphyrins derived from 5-(2,6-dichlorophenyl)dipyrromethane. Application of the same conditions to condensations involving 5-phenyldipyrromethane showed extensive rearrangement. Examination of a wide range of conditions showed that slow reactions are associated with less rearrangement. Two sets of conditions were identified that gave little or no scrambling: (1) condensation at 10 mM in MeCN at 0 °C with BF3-Et2O catalysis in the presence Of NH4Cl followed by DDQ oxidation and (2) condensation at 0.1 M in DMSO at 100 °C in the presence of NH4Cl (with no added acid catalyst) with air oxidation. Although yields are typically less than 10%, the elimination of the need to perform tedious chromatography improves the methodology available for the preparation of trans-porphyrins, derived from sterically unhindered dipyrromethanes.

Synthesis of meso-tetraphenyl porphyrins via condensation of dipyrromethanes with N-tosyl imines

A new synthetic route for the synthesis of 5,10,15,20-tetraphenyl porphyrins has been developed based on the reaction of 5-substituted dipyrromethanes with N-tosyl imines in the presence of a metal triflate catalyst. meso-Substituted tetraphenyl porphyrins were synthesized in a two-step process. The first step of the method is the metal triflate-catalyzed condensation of 5-substituted dipyrromethanes with N-tosyl imines to form a porphyrinogen intermediate and the second step is the oxidation of the porphyrinogen to porphyrin. The method was applied to the synthesis of trans-A2B2-tetraarylporphyrins and the products were obtained with only a trace amount of one scrambling product. The synthesis of two important building blocks for porphyrin synthesis, mono and di-sulfonamide alkylated 5-substituted dipyrromethanes, was achieved by the addition of 5-substituted dipyrromethane to N-tosyl imine. The application of mono and di-sulfonamide alkylated 5-substituted dipyrromethanes in '2+2' porphyrin formation reactions is presented.

Investigation of streamlined syntheses of porphyrins bearing distinct meso substituents

The use of porphyrins in fundamental studies and diverse applications requires facile access to ample quantities of material in pure form. The existing conditions for the condensation of a dipyrromethane plus a dipyrromethane-dicarbinol employ 2.5 mM reac

Boron complexation strategy for use in manipulating 1-acyldipyrromethanes

A method of making a metal complex comprises combining a 1-monoacyldipyrromethane with a compound of the formula R1R2MX, wherein M is boron, R1 and R2 are each independently organic substituents; and X is an anion leaving group; to produce a metal complex of the formula DMR1R2 wherein DH is a 1-monoacyldipyrromethane. The methods and complexes are useful for the purification and synthesis of dipyrromethanes and porphyrins.

Boron-complexation strategy for use with 1-acyldipyrromethanes

1-Acyldipyrromethanes are important precursors in rational syntheses of diverse porphyrinic compounds. 1-Acyldipyrromethanes are difficult to purify, typically streaking upon chromatography and giving amorphous powders upon attempted crystallization. A solution to this problem has been achieved by reacting the 1-acyldipyrromethane with a dialkylboron triflate (e.g., Bu 2B-OTf or 9-BBN-OTf) to give the corresponding B,B-dialkyl-B-(1- acyldipyrromethane)boron(III) complex. The reaction is selective for a 1-acyldipyrromethane in the presence of a dipyrromethane. The 1-acyldipyrromethane-boron complexes are stable to routine handling, are soluble in common organic solvents, are hydrophobic, crystallize readily, and chromatograph without streaking. The 1-acyldipyrromethane can be liberated in high yield from the boron complex upon treatment with 1-pentanol. Alternatively, the 1-acyldipyrromethane-boron complex can be used in the formation of a trans-A2B2-porphyrin. In summary, the boron-complexation strategy has broad scope and greatly facilitates the isolation of 1-acyldipyrromethanes.

9-Acylation of 1-acyldipyrromethanes containing a dialkylboron mask for the α-acylpyrrole motif

1,9-Diacyldipyrromethanes are important precursors to porphyrins, yet synthetic access remains limited owing to (1) poor conversion in the 9-acylation of 1-acyldipyrromethanes and (2) handling difficulties because acyldipyrromethanes typically streak upon

A Tin-Complexation Strategy for Use with Diverse Acylation Methods in the Preparation of 1,9-Diacyldipyrromethanes

The acylation of dipyrromethanes to form 1,9-diacyldipyrromethanes is an essential step in the rational synthesis of porphyrins. Although several methods for acylation are available, purification is difficult because 1,9-diacyldipyrromethanes typically st

Facile synthesis of meso-substituted dipyrromethanes and porphyrins using cation exchange resins

The macroporosity and acidity of cation exchange resins play a crucial role in the synthesis of dipyrromethanes and porphyrins; for the first time, cation exchange resins have been used as heterogeneous solid acid catalysts to produce dipyrromethanes and porphyrins in good yields. The reaction, at room temperature, of substituted aromatic aldehydes with pyrrole catalysed by cation exchange resin afforded the corresponding meso-substituted dipyrromethane in yields ranging from 70 to 80%, indicating the broad scope of the reaction. Further, the condensation of meso-substituted dipyrromethane with similar or different substituted aromatic aldehydes, using cation exchange resins furnished meso-tetrakis-symmetrical and mixed porphyrins, respectively. One-pot synthesis of porphyrins can also be carried out directly from the aldehydes and pyrrole under the above conditions. Acidolysis of the dipyrromethane is negligible under the conditions of the porphyrin-forming reaction.

Methods of making porphyrins and related compounds with Lewis acids

The present invention provides methods of making porphyrins and related compounds such as chlorins by condensing suitable starting materials (e.g., a dipyrromethane-dicarbinol plus dipyrromethane) in a polar solvent in the presence of a Lewis acid. The reactions are preferably carried out in a manner that minimizes rearrangement of the reaction product.