98-88-4Relevant articles and documents
PCl3-mediated transesterification and aminolysis of tert-butyl esters via acid chloride formation
Wu, Xiaofang,Zhou, Lei,Li, Fangshao,Xiao, Jing
, p. 491 - 497 (2021/01/20)
A PCl3-mediated conversion of tert-butyl esters into esters and amides in one-pot under air is developed. This novel protocol is highlighted by the synthesis of skeletons of bioactive molecules and gram-scale reactions. Mechanistic studies revealed that this transformation involves the formation of an acid chloride in situ, which is followed by reactions with alcohols or amines to afford the desired products.
Photo-on-Demand Synthesis of Vilsmeier Reagents with Chloroform and Their Applications to One-Pot Organic Syntheses
Liang, Fengying,Eda, Kazuo,Okazoe, Takashi,Wada, Akihiro,Mori, Nobuaki,Konishi, Katsuhiko,Tsuda, Akihiko
, p. 6504 - 6517 (2021/05/06)
The Vilsmeier reagent (VR), first reported a century ago, is a versatile reagent in a variety of organic reactions. It is used extensively in formylation reactions. However, the synthesis of VR generally requires highly toxic and corrosive reagents such as POCl3, SOCl2, or COCl2. In this study, we found that VR is readily obtained from a CHCl3 solution containing N,N-dimethylformamide or N,N-dimethylacetamide upon photo-irradiation under O2 bubbling. The corresponding Vilsmeier reagents were obtained in high yields with the generation of gaseous HCl and CO2 as byproducts to allow their isolations as crystalline solid products amenable to analysis by X-ray crystallography. With the advantage of using CHCl3, which bifunctionally serves as a reactant and a solvent, this photo-on-demand VR synthesis is available for one-pot syntheses of aldehydes, acid chlorides, formates, ketones, esters, and amides.
Remarkably Efficient Iridium Catalysts for Directed C(sp2)-H and C(sp3)-H Borylation of Diverse Classes of Substrates
Chattopadhyay, Buddhadeb,Hassan, Mirja Md Mahamudul,Hoque, Md Emdadul
supporting information, p. 5022 - 5037 (2021/05/04)
Here we describe the discovery of a new class of C-H borylation catalysts and their use for regioselective C-H borylation of aromatic, heteroaromatic, and aliphatic systems. The new catalysts have Ir-C(thienyl) or Ir-C(furyl) anionic ligands instead of the diamine-type neutral chelating ligands used in the standard C-H borylation conditions. It is reported that the employment of these newly discovered catalysts show excellent reactivity and ortho-selectivity for diverse classes of aromatic substrates with high isolated yields. Moreover, the catalysts proved to be efficient for a wide number of aliphatic substrates for selective C(sp3)-H bond borylations. Heterocyclic molecules are selectively borylated using the inherently elevated reactivity of the C-H bonds. A number of late-stage C-H functionalization have been described using the same catalysts. Furthermore, we show that one of the catalysts could be used even in open air for the C(sp2)-H and C(sp3)-H borylations enabling the method more general. Preliminary mechanistic studies suggest that the active catalytic intermediate is the Ir(bis)boryl complex, and the attached ligand acts as bidentate ligand. Collectively, this study underlines the discovery of new class of C-H borylation catalysts that should find wide application in the context of C-H functionalization chemistry.
Immobilization of (l)-valine and (l)-valinol on SBA-15 nanoporous silica and their application as chiral heterogeneous ligands in the Cu-catalyzed asymmetric allylic oxidation of alkenes
Samadi, Saadi,Ashouri, Akram,Rashid, Hersh I,Majidian, Shiva,Mahramasrar, Mahsa
supporting information, p. 17630 - 17641 (2021/10/04)
SBA-15 nanoporous silica was synthesized by hydrothermal method using P123 surfactant and tetraethoxyortosilicate in acidic condition and then functionalized by 3-chloropropyltrimethoxysilane. Next, by immobilization of chiral amino acid (S)-2-amino-3-methyl butanoic acid (l-valine) and chiral amino alcohol (S)-2-amino-3-methylbutane-1-ol (l-valinol), preparedviathe reduction ofl-valine by NaBH4/I2in THF, on functionalized-SBA-15, chiral heterogeneous ligands AL*-i-Pr-SBA-15 and AA*-i-Pr-SBA-15 were prepared and characterized by FT-IR, XRD, TGA, EDX, SEM, BET-BJH techniques. The asymmetric allylic oxidation of alkenes was done using copper-complexes of these ligands and the as-synthesized peresters. The reactions were optimized by varying various parameters such as temperature, solvent, amount of chiral heterogeneous ligand, as well as the type and amount of copper salt. Under optimized conditions, 6 mg of AL*-i-Pr-SBA-15 and 3.2 mol% of Cu(CH3CN)4PF6in acetonitrile at 50 °C, the chiral allylic ester was obtained with 80% yield and 39% enantiomeric excess in 24 h. The recyclability of the chiral heterogeneous catalysts was also evaluated without significant reduction in the reaction results up to three runs.
Butyrylcholine esterase selective inhibitor as well as preparation method and application thereof
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Paragraph 0035; 0039-0040, (2021/06/22)
The invention discloses a butyrylcholine esterase selective inhibitor as well as a preparation method and application thereof. The inhibitor is a compound shown as a formula (I). The invention also discloses application of the compound in preparation of d
Photochemical Activation of Aromatic Aldehydes: Synthesis of Amides, Hydroxamic Acids and Esters
Nikitas, Nikolaos F.,Apostolopoulou, Mary K.,Skolia, Elpida,Tsoukaki, Anna,Kokotos, Christoforos G.
supporting information, p. 7915 - 7922 (2021/05/03)
A cheap, facile and metal-free photochemical protocol for the activation of aromatic aldehydes has been developed. Utilizing thioxanthen-9-one as the photocatalyst and cheap household lamps as the light source, a variety of aromatic aldehydes have been activated and subsequently converted in a one-pot reaction into amides, hydroxamic acids and esters in good to high yields. The applicability of this method was highlighted in the synthesis of Moclobemide, a drug against depression and social anxiety. Extended and detailed mechanistic studies have been conducted, in order to determine a plausible mechanism for the reaction.
One-step Conversion of Amides and Esters to Acid Chlorides with PCl3
Li, Fangshao,Wu, Xiaofang,Guo, Fengzhe,Tang, Zi-Long,Xiao, Jing
supporting information, p. 4314 - 4317 (2021/07/16)
A general and efficient iodine-promoted chlorination of amides and esters with phosphorus trichloride is described. For the first time. Various inactivated amides including secondary and tertiary amides were directly converted to the corresponding acid chlorides in one-step. The substrate scope of methyl esters including aromatic and aliphatic esters was also explored under this system. This method is simple, scalable and wide in scope, which provides an approach to preparation of these acid chlorides.
Reaction pathway change on plasmonic Au nanoparticles studied by surface-enhanced Raman spectroscopy
Li, Ran,Zhang, Can-Can,Wang, Dan,Hu, Yan-Fang,Li, Yong-Long,Xie, Wei
supporting information, p. 2846 - 2850 (2021/05/29)
Gold nanoparticles (Au NPs) are nanoscale sources of light and electrons, which are highly relevant for their extensive applications in the field of photocatalysis. Although a number of research works have been carried out on chemical reactions accelerated by the energetic hot electrons/holes, the possibility of reaction pathway change on the plasmonic Au surfaces has not been reported so far. In this proof-of-concept study, we find that Au NPs change the reaction pathway in photooxidation of alkyne under visible light irradiation. This reaction produces benzil ([sbnd]CO[sbnd]CO[sbnd]) without the presence of Au NPs. In contrast, as indicated by surface-enhanced Raman spectroscopic (SERS) results, the C[sbnd]C triple bonds ([sbnd]C[tbnd]C[sbnd]) adsorbed on Au NPs are converted into carboxyl ([sbnd]COOH) and acyl chloride ([sbnd]COCl) groups. The plasmonic Au NPs not only provide energetic charge carriers but also activate the reactant molecules as conventional heterogeneous catalysts. This study discloses the second role of plasmonic NPs in photocatalysis and bridges the gap between plasmon-driven and conventional heterogeneous catalysis.
Preparation method of benzoyl chloride compound
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Paragraph 0037-0053, (2021/06/22)
The invention provides a preparation method of a benzoyl chloride compound. The preparation method comprises the following step: with a trichloromethyl benzene compound and a benzoic acid compound as raw materials and ferric oxide as a catalyst, carrying out a catalytic reaction to prepare the benzoyl chloride compound. According to the method disclosed by the invention, the benzoyl chloride compound can be obtained under the condition of not using a solvent, yield is up to 95% or above, atom economy is good, cost is lower, operation is simpler, more convenient and safer, the treatment amount of three wastes is smaller, the three wastes is easier to treat, and the method is more suitable for industrial production.
Preparation method of 3-chloropropionyl chloride
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Paragraph 0019-0021, (2021/10/27)
The invention provides a preparation method of 3-chloropropionyl chloride, wherein the preparation method comprises the following steps: mixing acrylic acid with a certain amount of catalyst, dropwise adding a certain amount of trichlorotoluene at a certain temperature under the protection of nitrogen, reacting for a period of time, and performing vacuum rectification to respectively obtain 3-chloropropionyl chloride and benzoyl chloride. The preparation method has the following beneficial effects: 1) acrylic acid and trichlorotoluene are adopted as raw materials, 3-chloropropionyl chloride is prepared in the presence of a catalyst, and benzoyl chloride with wide application is produced as a byproduct; the reaction route is environment-friendly, the process is simple, no emission is generated, and the requirement of atom economy is met; and the technical problem that toxic raw materials are used in the prior art is solved, and the technical problem that by-products polluting the environment are possibly generated in the prior art is also solved; and 2) the method is low in production cost, and in addition, the reaction route is combined with the specific reaction conditions, so that the yield of the obtained product is quite high and reaches 95% or above.
