Refernces
10.1002/adsc.201700587
The research focuses on the development of a metal-free and direct synthesis method for 5-[(N,N-disulfonylamino)methyl]oxazoles through the cycloisomerization-amination sequence of N-propargyl carboxamides with bis(sulfonyl)imides, facilitated by (diacetoxyiodo)benzene or iodine(III) catalysts generated in situ from iodobenzene precatalyst and Oxone. The experiments involved the optimization of reaction conditions, including the selection of solvents and the amount of bis(sulfonyl)imides, to maximize the yield of oxazoles bearing nitrogen functional groups. Reactants such as N-propargyl carboxamides and bis(sulfonyl)imides were utilized, and the reactions were analyzed using techniques like NMR spectroscopy and silica gel column chromatography for product isolation and yield determination. The study also proposed a reaction mechanism based on NMR studies and deuterium labeling experiments, which indicated the involvement of specific intermediates and the absence of alkynyliodonium species in the cyclization process.
10.1039/c001465f
The research focuses on the development of new synthetic strategies for the synthesis of highly functional erythrina, oxindole, and pyrrolidinoindoline skeletons, which are structural motifs found in bioactive alkaloids. The experiments involve the use of 4-aminophenol-derived amides as building blocks for these complex alkaloid structures. Key reactants include 4-aminophenol, homoveratroyl chloride, lithium aluminium hydride, and ethyl 3-chloro-3oxopropanoate, among others. The oxidative dearomatization process is central to the synthesis, utilizing iodobenzene diacetate (IBD) in methanol to form cyclohexenone intermediates, which are then further reacted with allyl bromide and potassium carbonate to yield oxindoles. The study also reports an unprecedented rearrangement leading to the formation of 3-hydroxyoxindole and the synthesis of a mimic of the natural alkaloid CPC-1. Analytical techniques such as 1H NMR and 13C NMR spectroscopy were employed to characterize key intermediates and final products, confirming the success of the synthetic routes and the structural diversity of the synthesized compounds.
10.1007/s00044-013-0656-7
The study focuses on the synthesis, characterization, and in vitro antimicrobial evaluation of a series of new 5-chloro-8-bromo-3-aryl-1,2,4-triazolo[4,3-c]pyrimidines (4a–j). These compounds were synthesized through oxidative cyclization of pyrimidinylhydrazines (3a–j) derived from various aryl aldehydes, using iodobenzene diacetate as the oxidizing agent in methanol. The synthesized compounds were confirmed through elemental analyses, FT-IR, 1H NMR, 13C NMR, and mass spectral studies. The purpose of these chemicals was to test their antimicrobial activity against clinically isolated strains of bacteria and fungi. The study found that compounds 4f, 4i, and 4j demonstrated good antimicrobial activity against all tested microbial strains, indicating their potential as leads for further development in antimicrobial chemotherapy.
10.1039/c8nj03822h
The study presents a mild and selective method for the halogenation of indole C–H bonds using phenyliodine diacetate (PhI(OAc)2) in combination with sodium halides (NaX) as the halogen source. This protocol enables the chlorination, bromination, and iodination of a wide array of indole substrates under mild conditions, providing straightforward access to valuable 3-haloindole derivatives. The combination of NaX and PhI(OAc)2 acts as an effective halogenating system, overcoming limitations associated with conventional metal catalysts. The study demonstrates that the electronic characteristics of substituents on the indole ring have minimal influence on the reaction yields, and the method is also applicable to heterocycles such as imidazole. The halogenated products obtained are valuable synthons for the synthesis of bioactive molecules and marketed drugs.
10.1021/jo300169k
The study investigates oxidative 1,2- and 1,3-alkyl shift processes mediated by hypervalent iodine reagents, specifically focusing on simple and inexpensive phenol derivatives. These transpositions enable the rapid redesign of the main aromatic skeleton to generate highly functionalized scaffolds containing a prochiral dienone system, a quaternary carbon center connected to as many as four sp2 centers, and a carbonyl functionality or precursor. The researchers used iodobenzene diacetate (DIB) as the hypervalent iodine reagent, and solvents such as hexafluoroisopropyl alcohol (HFIP) to stabilize the phenoxonium ion intermediates. The study demonstrates an efficient enantioselective version of this process, resulting in the formation of a challenging quaternary carbon center. The products represent the central cores of several natural products with important bioactivities. The study also includes the rapid synthesis of several functionalized polycyclic systems and a formal synthesis of acetylaspidoalbidine, a hexacyclic alkaloid belonging to the Aspidosperma family.
10.1016/j.tet.2013.04.122
The study investigates a novel method for synthesizing a-acetoxy ketones using silver(I) as a catalyst. The primary chemicals involved are terminal alkynes and (diacetoxyiodo)benzene (PhI(OAc)2), with silver(I) compounds, specifically silver acetate (CH3COOAg), playing a crucial role in catalyzing the reaction. The reaction is conducted in wet acetonitrile at room temperature, yielding a-acetoxy ketones with high efficiency (55-93% yields). The study highlights the effective utilization of PhI(OAc)2, the high chemoselectivity, excellent yields, mild reaction conditions, and experimental simplicity of this method. The authors propose a plausible mechanism involving the activation of the terminal alkynes by silver(I), followed by the addition of an acetate anion to form key intermediates, which ultimately leads to the formation of a-acetoxy ketones. This method represents a significant advancement in the synthesis of a-acetoxy ketones, particularly from terminal aryl alkynes, offering a more efficient and environmentally friendly alternative to existing procedures.
10.1016/j.chempr.2019.07.023
This study presents a novel dimeric gold-catalyzed oxidative cross-coupling method for the synthesis of a diverse range of biaryl compounds using arylboronates and arylsilanes. The method overcomes the limitations of traditional gold-catalyzed o,p-orientation rules and is effective for electron-rich arenes through C–H bond activation. It exhibits excellent tolerance for various functional groups and offers a flexible synthetic approach to (pseudo)halogenated biaryls. The research demonstrates the unique catalytic efficiency of a dimeric gold complex and the preparation of biaryl pharmacophores under pseudoneutral conditions, which is significant for the synthesis of complex organic materials and pharmaceuticals. The study also includes the successful synthesis of several biaryl pharmacophores and p-conjugated organic materials, highlighting the method's synthetic value and versatility.
10.1016/j.tetlet.2017.07.074
The study presents the first total synthesis of greensporone C, a cytotoxic 14-membered resorcylic acid lactone with potential biological activities such as cytotoxicity against certain cancer cell lines. The synthesis involved a 16-step linear sequence with a 3.3% overall yield. Key chemicals used in the study include Mitsunobu reagents for esterification to construct the macrocycle and establish the (E)-olefin geometry, benzoic acid derivatives and (R)-non-8-en-2-ol as key fragments for the synthesis, and various protecting groups and reagents such as ethoxymethyl (EOM), t-butyldimethylsilyl chloride (TBSCl), and iodobenzene diacetate for protecting and modifying functional groups. The purpose of these chemicals was to construct the complex structure of greensporone C, confirm its absolute stereochemistry, and potentially unlock its biological activities for further study and application.
10.1021/ol300166q
The study presents a metal-free procedure for the intramolecular oxidative diamination and aminohydroxylation of olefins. The key chemicals involved are iodobenzene diacetate (PhI(OAc)2) as the oxidant and a halide additive, such as n-Bu4NCl or KI, which significantly enhances the reaction efficiency. The substrates include olefins tethered with disulfonamides, ureas, or hydroxysulfonamides. The reaction proceeds at room temperature and is characterized by mild conditions, a broad substrate scope, and excellent functional group tolerance. The halide additive is crucial for generating an active hypohalite species that promotes the formation of the desired bisindolines and aminohydroxylation products. The study also proposes a mechanistic pathway involving the formation of a halonium intermediate and subsequent intramolecular addition and SN2 replacement reactions.
10.1016/S0040-4020(01)89811-2
This study presents an improved method for the synthesis of (+)-carbocyclic 2'-deoxyadenosine, a nucleoside analog with potential antiviral properties, starting from the bicyclic lactone diol (+)-1. The key steps involve the sequential iodide decarboxylation of the carboxylic acid side chain derived from the lactone moiety of (+)-1 using iodobenzene diacetate (IBDA) and a hypervalent iodine species. The tetrahydropyranyl (THP) group was used for protection, replacing the secondary mesyloxy functionality with an azide anion, while a complete inversion of the configuration was performed. The heterocyclic moiety (adenine) was constructed by a modified literature method involving the reduction of NO2 to NH2 groups with SnCl2. The study also reports an unexpected formation of a disubstituted 2-oxabicyclo[2.2.1]heptane skeleton formed via a hypervalent iodine species derived from the intermediate. The overall yield and purity of the final product were improved, highlighting the efficiency of the synthetic route and the importance of the reagents and conditions used.
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