Refernces
10.1021/ic502791y
The solid-phase synthesis and screening platform was successful in identifying lead caging groups that release ligands with visible light, demonstrating the utility of this approach for discovering new metal-based caging groups.
10.1021/ol0157813
The study presents a novel strategy for synthesizing polypeptides using recombinant proteins, which are nonprotected peptides, in conjunction with S-alkyl peptide thioesters as building blocks. The method involves oxidizing the N-terminal serine of a peptide to form an Nr-glyoxyloyl peptide, which then undergoes reductive amination with 4,5-dimethoxy-2-(triphenylmethylthio)benzylamine to attach a thiol linker. This results in an Nr-4,5-dimethoxy-2-mercaptobenzyl glycyl peptide, which can be condensed with a peptide thioester to form a peptide bond. The innovative aspect of this approach is the use of the 4,5-dimethoxy-2-mercaptobenzyl (Dmmb) group as a linker, which can be removed under acidic conditions, allowing for the synthesis of peptides with native peptide bonds. The study demonstrates this method using a model sequence and shows the successful preparation of a thiol linker-attached peptide for condensation with peptide thioesters, providing a useful method for peptide synthesis in a neutral aqueous environment without the need for protecting groups.
10.1021/jm1006325
The research focuses on the design, synthesis, and in vitro pharmacological evaluation of new radiolabeled ?-Hydroxybutyric Acid (GHB) analogues, including photolabile analogues with irreversible binding to high-affinity GHB binding sites. The study aimed to develop tools for isolating and identifying the high-affinity GHB binding site, which is crucial for understanding GHB's action as a neuromodulator and therapeutic drug. The researchers synthesized a series of high-affinity and selective lipophilic GHB analogues, one of which was radiolabeled with 125I to achieve higher specific radioactivity. Trifluoroacetic acid was used in the conversion of arylamine moieties into arylazide groups. They also incorporated a photoaffinity label to enable irreversible binding to the high-affinity GHB binding sites. The synthesized compounds were tested for their ability to compete for binding with the commercially available GHB radioligand [3H]NCS-382 in rat brain cortical membranes. The experiments involved radioiodination using the chloramine-T method, HPLC purification, and in vitro pharmacological evaluations. The results showed that the novel photoaffinity radioligand [125I]4-hydroxy-4-[4-(2-azido-5-iodobenzyloxy)phenyl]butanoic Acid (6) could covalently link with the high-affinity GHB binding site upon UV irradiation, demonstrating its potential as a tool for identifying the GHB high-affinity binding protein.
10.1080/00397910802419680
The research focuses on the efficient synthesis of 7-amino-3-hydroxyindan-1-one, a three-dimensional, three-point scaffold with potential applications in constructing focused compound libraries for biological interactions. The synthesis is achieved through a three-step process: first, reacting 4-nitrophthalic anhydride with ethyl acetoacetate, acetic anhydride, and triethylamine in methylene chloride to produce compound 10; second, hydrolyzing and decarboxylating compound 10 with trifluoroacetic acid in acetonitrile to yield 4-nitroindan-1,3-dione (11); and third, reducing compound 11 using catalytic hydrogenation with 10% Pd/C in methanol to obtain the final product, 7-amino-3-hydroxyindan-1-one (7). The structure of compound 7 was confirmed using heteronuclear multiple bond correlation (HMBC) spectral studies. The article also details the preparation of N-substituted derivatives of compound 7 and provides their physical constants, spectral data, and yields. Analytical techniques used include NMR spectroscopy, LC/MS, and melting point determination, ensuring the purity and structure of the synthesized compounds.
10.1016/j.tetlet.2008.01.026
The study presents the development of a polystyrene-immobilized pyrrolidine (compound 4) as an efficient, reusable, and stereoselective organocatalyst for the asymmetric Michael addition of cyclohexanone to nitroolefins. The catalyst, when combined with trifluoroacetic acid (TFA), enabled the reaction to proceed with high yields (up to >99%) and excellent diastereoselectivities (up to >99:1 dr) and enantioselectivities (up to >99% ee). The purpose of the chemicals used was to facilitate a carbon-carbon bond-formation reaction, which is a crucial process in organic synthesis. The study highlights the environmental friendliness and efficiency of the organocatalyst, as it can be recovered and recycled through simple filtration for more than 10 consecutive trials without significant loss of catalytic activity.
10.1016/S0040-4039(01)90354-5
The study presents an efficient methodology for the synthesis of indole derivatives in a single operation using organodilithium reagents and vicinal dication equivalents. Key chemicals involved include 2-bromoaniline derivatives, which are used to prepare organodimetallic reagents through bromine-lithium exchange, a process that facilitates efficient, site-specific lithiation. For instance, 2'-bromo-2,2-dimethylpropionanilide reacts with methyllithium and t-butyllithium to form the organodilithium derivative. This derivative is then reacted with biselectrophiles such as 2-chlorocyclohexanone to produce indole precursors. The study also explores the effects of variations in nitrogen protecting groups and reaction temperatures. The methodology allows for the formation of either N-protected or unprotected indoles, with dehydration induced by trifluoroacetic acid yielding N-protected products like 3,4-tetrahydrocarbazole. The study further demonstrates the versatility of the method by using different biselectrophiles, such as the enolate of cyclohexenone epoxide and enediones, to produce various indole derivatives. The results highlight the regiocontrol and synthetic efficiency of this approach, with high yields and the ability to directly convert commercially available 2-bromoaniline to tetrahydrocarbazole in one operation.
10.1016/j.tetlet.2003.11.133
The study presents a concise synthesis method for a novel class of homochiral aromatic amino acid surrogates, featuring tetrahydroindazole or benzisoxazole systems. These surrogates were synthesized through the acylation of cyclic 1,3-diketone by the side-chain carboxyl functionality of specific amino acid precursors, followed by a regioselective condensation with hydrazine, N-benzylhydrazine, and hydroxylamine. The synthetic strategy is versatile, allowing for the creation of structurally diverse derivatives. These novel amino acids can be efficiently incorporated into proteins and have potential applications in imparting unique properties to biological peptides. The study also includes the synthesis of Na-Fmoc-protected derivatives, which are useful for solid-phase peptide assembly, and the exploration of the stereochemistry integrity of the homochiral starting material through chemical transformations. The synthesized amino acids offer opportunities as structural surrogates of tryptophan and as building blocks for designing molecular probes.
10.1016/S0960-894X(01)00710-7
The study focuses on the discovery of small molecule carbamates as potent dual antagonists for the integrins α4β1 and α4β7, which are involved in inflammatory diseases. Through structure-activity relationship (SAR) studies, the researchers identified new binding sites and synthesized derivatives of (N-arylsulfonyl)-prolyl-tyrosyl compounds. The study revealed that specific modifications, such as the introduction of carbamate groups, significantly improved binding affinity to the α4β7 integrin by 200 to 400-fold, while maintaining high potency for α4β1. The research highlights the potential of these compounds as therapeutic agents for inflammatory diseases such as asthma and inflammatory bowel disease by inhibiting cell adhesion processes mediated by these integrins.
10.1021/ja046965q
The study presents a novel synthetic strategy for the creation of dendronized protein polymers (DPPs), which are cylindrical macromolecules with well-defined lengths and diameters. The researchers combined biological and chemical methods to achieve this precision. They expressed a monodisperse, R-helical polypeptide backbone in bacteria using a DNA template, which determined the length and overall rod shape of the DPP. Subsequently, synthetic dendrons were grafted onto the polypeptide backbone's reactive amino acid side chains, creating a dendritic shell that controlled the thickness. The resulting DPPs self-assembled into highly ordered liquid crystalline structures due to their uniform shape and size. The research demonstrated that these DPPs could be tailored in terms of size and chemical functionality, and their self-assembly was driven by excluded volume interactions, leading to long-range order in their liquid crystalline phases. This approach opens up new possibilities for the design of materials with predictable properties at the nanoscale.
10.3184/174751911X13182405888457
The research presents a study on the preparation of methyl (2-hydroxynaphthalen-1-yl)(aryl)methyl/benzylcarbamate derivatives using magnesium (II) 2,2,2-trifluoroacetate as an efficient catalyst. The methodology involves multi-component condensation reactions of aldehydes, 2-naphthol, and methyl/benzyl carbamate, resulting in the synthesis of various derivatives in high yields. The catalyst, Mg(OOCCF3)2, was prepared from trifluoroacetic acid and magnesium chloride and characterized through powder X-ray diffraction. The experiments involved optimizing reaction conditions such as catalyst amount, temperature, and solvent, with the best results achieved under solvent-free conditions at 100°C using 0.1 mmol of catalyst. Various aromatic aldehydes were tested, and the reaction was influenced by the electronic and steric properties of the aldehydes. The products were purified by simple filtration and crystallization from ethanol, and their structures were confirmed using NMR and IR spectroscopy, as well as elemental analysis. The study demonstrates an efficient method for synthesizing 1-carbamatoalkyl 2-naphthol derivatives with advantages such as good yields, simple procedure, shorter reaction times, and milder conditions.
10.1002/adsc.201900620
The research aims to develop a simple and efficient method for synthesizing 3-thiosubstituted pyrroles from homopropargylic amines and thiosulfonates through a tandem sulfenylation/cyclization process. The study explores the use of thiosulfonates as both substrates and oxidants, eliminating the need for external oxidants. The researchers optimized the reaction conditions, finding that a temperature of 100°C in toluene with sodium iodide (NaI) as a catalyst and trifluoroacetic acid (TFA) as an additive yielded the best results. The method demonstrated good functional group tolerance and produced a series of 3-thiosubstituted pyrrole derivatives in moderate to good yields. The study concludes that this direct synthesis method is a significant advancement in the field, offering a mild and efficient route for constructing C–C/C–S bonds, which could have broad applications in organic synthesis and medicinal chemistry.
C, 
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