1523-19-9Relevant academic research and scientific papers
Mechanically induced solvent-free esterification method at room temperature
Zheng, Lei,Sun, Chen,Xu, Wenhao,Dushkin, Alexandr V.,Polyakov, Nikolay,Su, Weike,Yu, Jingbo
, p. 5080 - 5085 (2021/02/05)
Herein, we describe two novel strategies for the synthesis of esters, as achieved under high-speed ball-milling (HSBM) conditions at room temperature. In the presence of I2 and KH2PO2, the reactions afford the desired esterification derivatives in 45% to 91% yields within 20 min of grinding. Meanwhile, using KI and P(OEt)3, esterification products can be obtained in 24% to 85% yields after 60 min of grinding. In addition, the I2/KH2PO2 protocol was successfully extended to the late-stage diversification of natural products showing the robustness of this useful approach. Further application of this method in the synthesis of inositol nicotinate was also discussed. This journal is
Metal-Free Selective Modification of Secondary Amides: Application in Late-Stage Diversification of Peptides
Adebomi, Victor,Sriram, Mahesh,Streety, Xavier,Raj, Monika
supporting information, p. 6189 - 6193 (2021/08/01)
Here we solve a long-standing challenge of the site-selective modification of secondary amides and present a simple two-step, metal-free approach to selectively modify a particular secondary amide in molecules containing multiple primary and secondary amides. Density functional theory (DFT) provides insight into the activation of C-N bonds. This study encompasses distinct chemical advances for late-stage modification of peptides thus harnessing the amides for the incorporation of various functional groups into natural and synthetic molecules.
Preparation of Carbamates, Esters, Amides, and Unsymmetrical Ureas via Br?nsted Acid-Activated N-Acyl Imidazoliums
Watson, Rebecca B.,Butler, Todd W.,Deforest, Jacob C.
supporting information, p. 500 - 506 (2021/01/09)
We report the application of Br?nsted acid-activated N-acyl imidazoliums as versatile intermediates in carbonyl transformations. The efficient and scalable procedure was validated on a diverse set of carbamates, esters, amides, and unsymmetrical ureas (21 examples, up to 91% yield). Additionally, we exemplify this method on multikilogram scale for the synthesis of an electron-deficient carbamate.
Hydrogen-bond-assisted transition-metal-free catalytic transformation of amides to esters
Huang, Changyu,Li, Jinpeng,Wang, Jiaquan,Zheng, Qingshu,Li, Zhenhua,Tu, Tao
, p. 66 - 71 (2020/11/18)
The amide C-N cleavage has drawn a broad interest in synthetic chemistry, biological process and pharmaceutical industry. Transition-metal, luxury ligand or excess base were always vital to the transformation. Here, we developed a transition-metal-free hydrogen-bond-assisted esterification of amides with only catalytic amount of base. The proposed crucial role of hydrogen bonding for assisting esterification was supported by control experiments, density functional theory (DFT) calculations and kinetic studies. Besides broad substrate scopes and excellent functional groups tolerance, this base-catalyzed protocol complements the conventional transition-metal-catalyzed esterification of amides and provides a new pathway to catalytic cleavage of amide C-N bonds for organic synthesis and pharmaceutical industry. [Figure not available: see fulltext.]
Carboxylic Acid Deoxyfluorination and One-Pot Amide Bond Formation Using Pentafluoropyridine (PFP)
Brittain, William D. G.,Cobb, Steven L.
, p. 5793 - 5798 (2021/08/01)
This work describes the application of pentafluoropyridine (PFP), a cheap commercially available reagent, in the deoxyfluorination of carboxylic acids to acyl fluorides. The acyl fluorides can be formed from a range of acids under mild conditions. We also demonstrate that PFP can be utilized in a one-pot amide bond formation via in situ generation of acyl fluorides. This one-pot deoxyfluorination amide bond-forming reaction gives ready access to amides in yields of ≤94%.
Method for preparing carboxylate aryl type compound
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Paragraph 0121-0126, (2020/02/10)
The invention belongs to the field of drug synthesis and in particular relates to a method for preparing a carboxylate aryltype compound. The preparation method provided by the invention comprises thefollowing steps: providing a compound A of a formula a shown in the description, a compound B of a formula b shown in the description, an organic palladium complex, and a silver salt, wherein the organic palladium complex is composed of a palladium compound and a nitrogen-containing ligand; the nitrogen-containing ligand comprises an o-phenoline compound and/or a bipyridine compound; and mixing the compound A, the compound B, the organic palladium complex and the silver salt in a reaction solvent, and performing a reaction in an inert gas atmosphere, so as to obtain the carboxylate aryl typecompound of a formula I shown in the description. As the organic palladium complex and the silver salt are simultaneously used, direct selectivity C-O coupling of carboxylic acid and halogenated aromatic hydrocarbon is realized, and the method is applicable to a variety of carboxylic acid substrates and halogenated aromatic substrates, and is wide in compatibility and high in yield.
Ligand-Controlled C?O Bond Coupling of Carboxylic Acids and Aryl Iodides: Experimental and Computational Insights
Li, Li,Song, Feifei,Zhong, Xiumei,Wu, Yun-Dong,Zhang, Xinhao,Chen, Jiean,Huang, Yong
supporting information, p. 126 - 132 (2019/11/28)
Palladium-catalyzed cross-coupling reactions between carboxylic acids and aryl halides have several possible competitive pathways. Decarboxylative C?C bond coupling and C?H arylation are well established in the literature. However, direct C?O bond coupling between carboxylic acids and aryl halides has received little success. In this report, we describe a protocol for exclusive C?O bond formation, enabled by a bidentate N,N-ligand such as 1,10-phenanthroline. The reaction is general for a broad range of carboxylic acids and iodoarenes. Experimental evidence and computational results suggest a high energy barrier for the alternative pathway of decarboxylative carbon-carbon bond coupling. (Figure presented.).
Dual aminoquinolate diarylboron and nickel catalysed metallaphotoredox platform for carbon-oxygen bond construction
Day, Craig,Jia, Xin,Wei, Lanfeng,Xu, Liang,Zu, Weisai
supporting information, p. 8273 - 8276 (2020/08/17)
Herein, aminoquinolate diarylboron complexes are utilized as photocatalysts in dual Ni/photoredox catalyzed carbon-oxygen construction reactions. Via this unified metallaphotoredox platform, diverse (hetero)aryl halides can be conveniently coupled with acids, alcohols and water. This method features operational simplicity, broad substrate scope and good compatibility with functional groups. This journal is
Photo-Fries rearrangement in flow under aqueous micellar conditions
Chen, Chun-Jen,Chien, Chia-Chen,Kao, Shih-Chieh,Wu, Yen-Ku
supporting information, p. 15470 - 15472 (2020/12/25)
A flow edition of photo-Fries rearrangement for the synthesis of 2-acylphenols in an aqueous micellar medium has been described. We take advantage of a narrow channel reactor and micelle-induced confinement effect to refine both the efficiency and selectivity of the parent photoreaction. This journal is
