Refernces
10.1021/jo200464g
This research investigates the interfacial regions governing the internal cavities of dendrimers, specifically poly(alkyl aryl ether) dendrimers with varying alkyl chain lengths. The purpose of the study is to understand how these interfacial regions, defined by the linkers connecting branch points within the dendrimers, affect the size and shape of the dynamic inner cavities, which are crucial for encapsulating guest molecules and mediating photoreactions. The researchers synthesized a series of dendrimers with ethyl, n-propyl, n-butyl, and n-pentyl groups as linkers and hydroxyl groups at the periphery, spanning the first to third generations. They used UV-vis and fluorescence spectroscopies to monitor the encapsulation of pyrene and coumarins by the dendrimers, finding that lower generation dendrimers with optimal alkyl linkers presented better encapsulation abilities. The photoreaction of dibenzyl ketone within these dendrimers revealed that third-generation dendrimers with an n-pentyl group as the linker exhibited a higher "cage effect," indicating greater ability to hold reactive intermediates and facilitate product formation with high selectivity. The chemicals used in the process include phloroglucinol, dibromoalkanes, NaOH, and various coumarin dyes, among others. The conclusions emphasize the importance of alkyl chain length in determining the hydrophobicity and reactivity within the dendrimers' inner cavities.
10.1021/ol101380a
The research focuses on the biomimetic synthesis of polycyclic polyprenylated acylphloroglucinol (PPAP) natural products, specifically ialibinone A, ialibinone B, and hyperguinone B, which are derived from Hypericum papuanum. The purpose of the study was to investigate biomimetic cascade reaction approaches to synthesize these complex PPAP natural products, which exhibit potent biological activities and are challenging synthetic targets. The researchers synthesized the proposed biosynthetic precursor 5 from phloroglucinol in three steps and then explored oxidative cyclizations of this compound to achieve the synthesis of the target PPAPs. The conclusions of the research indicated that a series of oxidative cyclization reactions could access a diverse group of polycyclic ring systems, with the synthesis of ialibinones A and B achieved through oxidative radical cyclization with PhI(OAc)2, hyperguinone B through oxidation with PhI(OAc)2 and TEMPO, and a compound with a bicyclo[3.3.1]nonane core through treatment with I2. The study demonstrated the potential of biomimetic approaches in synthesizing complex PPAP natural product structures.
10.1016/S0040-4039(98)01657-8
The research aims to develop an efficient synthesis of a peptidomimetic compound that mimics the key amino acids of omega-conotoxin MVIIA, a potent analgesic peptide from the cone shell Conus magus. The purpose of this study is to create a low molecular weight, non-peptide antagonist of N-type neuronal calcium channels, which could potentially serve as a more practical alternative to the peptide for treating severe neuropathic pain, given the high potency and non-addictive nature of omega-conotoxin MVIIA. The researchers employed a dendroid approach to attach side-chain mimetics of the key amino acids (Lys-2, Arg-10, Leu-11, Tyr-13, and Arg-21) to a dendritic backbone, using phloroglucinol as a core unit and introducing aryl ether linkages through Williamson and Mitsunobu etherifications. The synthesis resulted in the desired peptide analogue with high yield and confirmed its structure through NMR spectroscopy and HRMS analysis. The study concludes that the synthesized compound provides a versatile platform for further molecular modeling, organic synthesis, and biological screening, with ongoing biological evaluation to assess its potential as a therapeutic agent.
10.1021/ol060266w
The study reports the first total synthesis of (?)-xyloketal A, a C3-symmetric and biologically active natural product isolated from a mangrove fungus. The synthesis was achieved in one step from phloroglucinol (1,3,5-trihydroxybenzene) and (4R)-3-hydroxymethyl-2,4-dimethyl-4,5-dihydrofuran. The key step involved a boron trifluoride diethyl etherate-promoted triple electrophilic aromatic substitution reaction coupled to three bicyclic acetal formation reactions. The study also details the preparation of the chiral nonracemic alcohol precursor to (4R)-3-hydroxymethyl-2,4-dimethyl-4,5-dihydrofuran through a series of reactions starting from an oxazolidinone. The synthetic process demonstrated high diastereoselectivity, yielding a mixture of xyloketal A and its 2,6-epimer. The study highlights the potential of this synthetic method for the total synthesis of other members of the xyloketal family.
10.1016/S1872-2067(11)60477-4
The research explores the development of a novel and efficient catalytic method for synthesizing 4,4'-(arylmethylene)bis(1H-pyrazol-5-ol) derivatives using 1,3,5-tris(hydrogensulfato) benzene (THSB) as the catalyst. The study aims to address the limitations of existing methods, such as high costs, complex procedures, high temperatures, and long reaction times, by introducing a mild, efficient, and environmentally friendly alternative. Phloroglucinol (1,3,5-benzenetriol) is used as the starting material for the preparation of THSB. It reacts with chlorosulfonic acid to form the catalyst. Chlorosulfonic Acid is used to sulfonate phloroglucinol, resulting in the formation of THSB. It is a strong acid that provides the sulfato groups necessary for the catalytic activity of THSB. The results demonstrate that THSB effectively promotes the reaction, yielding high-quality products in excellent yields (90-98%) within short reaction times (2-5 minutes). The study concludes that the use of THSB offers significant advantages, including higher yields, milder reaction conditions, and shorter reaction times compared to other catalysts, making it a promising candidate for green chemistry applications. The researchers are further exploring the potential of THSB in other organic reactions.
10.1016/j.bmc.2010.06.077
The research discusses the synthesis and inhibitory activity of resorcinol and phloroglucinol derivatives of catechin and epicatechin against ribonuclease A (RNase A), with the aim of increasing the number of phenolic hydroxyl groups to enhance inhibition. The study concluded that these novel conjugates were more effective inhibitors of RNase A than catechin and epicatechin, highlighting the importance of phenolic hydroxyl groups in inhibiting ribonucleolytic activity. The research also explored the compounds' anti-angiogenic activity through the chorioallantoic membrane (CAM) assay, finding that the epicatechin-based polyphenols showed inhibition of angiogenin-induced angiogenesis. Chemicals used in the synthesis process included (+)-catechin, (-)-epicatechin, phloroglucinol, resorcinol, LiBr, and various protecting groups such as benzyl ether. The study employed techniques like fluorescence studies, protein-ligand docking, and CD spectroscopic studies to evaluate binding parameters and interactions.
10.1016/j.tet.2004.09.004
The research explores the acid-catalyzed condensation reactions of 2-hydroxy-2,20-biindan-1,10,3,30-tetrone with various phenols, methoxyaromatic systems, and enols. The purpose of this study is to investigate the electrophilic chemistry of 2-hydroxy-2,2-biindan-1,10,3,30-tetrone, a partially reduced derivative of hydrindantin, which is more stable in acidic conditions compared to hydrindantin itself. The researchers found that this compound readily reacts with a range of substrates to form 2-aryl/alkyl-2,20-biindan-1,10,3,30-tetrones and chromenes in high yields. Notably, resorcinol, 1,3,5-trihydroxybenzene, and a- and b-naphthols preferentially form intramolecular hemi-ketal structures, as confirmed by X-ray diffraction studies.
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