20386-93-0Relevant academic research and scientific papers
N-Aroylbenzotriazoles as Efficient Reagents for o-Aroylation in Absence of Organic Solvent
Hahnvajanawong, Viwat,Phungpis, Baramee
, p. 2671 - 2674 (2021/10/25)
N-Aroylbenzotriazoles have been shown to be efficient reagents for esterification in the absence of organic solvent. Grinding of N-aroylbenzoytiazoles with twofold excess of alcohols for a couple of hours at room temperature gave corresponding esters in high percentage of yields.
Iodine-catalyzed synthesis of β-uramino crotonic esters as well as oxidative esterification of carboxylic acids in choline chloride/urea: a desirable alternative to organic solvents
Moayyed, Mohammadesmaeil,Saberi, Dariush
, p. 445 - 455 (2020/09/07)
Abstract: Iodine-mediated selective synthesis of β-uramino crotonic esters was achieved via the reaction of β-dicarbonyls and urea at room temperature. Choline chloride/urea mixture, as an eco-friendly, cheap, non-toxic, and recyclable deep eutectic solvent (DES), was employed as sustainable media as well as reagent at the same time in these transformations. Some derivatives of β-uramino crotonic esters were synthesized with good to high yields without a tedious work-up. The process could be done to synthesize the above-mentioned compounds in gram scale. Moreover, oxidative cross-esterification of carboxylic acids with alkyl benzenes was carried out in the above-mentioned DES by the employment of tetrabutylammonium iodide (TBAI) as the catalyst and tert-butyl hydroperoxide (TBHP) as the oxidant at 80?°C. DES/TBAI system was reused up to five consecutive times. Graphic abstract: Iodine-catalyzed C–N and C–O bond formation in choline chloride/urea as a green solvent under the mild reaction conditions. Providing the clean procedure toward synthesis of β-uramino crotonic esters and benzylic esters.[Figure not available: see fulltext.].
Catalytic conversion of ketones to esters: Via C(O)-C bond cleavage under transition-metal free conditions
Subaramanian, Murugan,Ramar, Palmurukan M.,Rana, Jagannath,Gupta, Virendra Kumar,Balaraman, Ekambaram
supporting information, p. 8143 - 8146 (2020/09/09)
The catalytic conversion of ketones to esters via C(O)-C bond cleavage under transition-metal free conditions is reported. This catalytic process proceeds under solvent-free conditions and offers an easy operational procedure, broad substrate scope with excellent selectivity, and reaction scalability. This journal is
Rhodium-Catalyzed Reductive Esterification Using Carbon Monoxide as a Reducing Agent
Ostrovskii, Vladimir S.,Runikhina, Sofiya A.,Afanasyev, Oleg I.,Chusov, Denis
supporting information, p. 4116 - 4121 (2020/07/13)
Carbon monoxide used to have a limited number of applications in organic chemistry, but it gradually increases its role as a mild and selective reducing agent. It can be applied for the carbon–heteroatom single bond formation via the reductive addition of hydrogen-containing nucleophiles to carbonyl compounds. In this paper, rhodium-catalyzed reductive esterification is described, and a comparative study of the rhodium and ruthenium catalysis in the reductive addition reactions is provided. Rhodium performs better on highly nucleophilic substrates and ruthenium is better for compounds with less nucleophilicity.
Flavin Catalysis Employing an N(5)-Adduct: an Application in the Aerobic Organocatalytic Mitsunobu Reaction
M?rz, Michal,Babor, Martin,Cibulka, Radek
supporting information, p. 3264 - 3268 (2019/06/08)
An artificial flavin system has been firstly proved to employ an N(5)-adduct for a catalytic transformation. This mode of catalysis occurs in some flavoenzymes but it is unknown in chemocatalysis, still exclusively using only C(4a)-adducts. In our report, an ethylene-bridged biomimetic flavin has been shown to participate in the Mitsunobu esterification reaction as an alternative to dialkyl azodicarboxylate. The reaction occurs via a flavin N(5)-triphenylphosphane adduct and is catalytic from the point of view of the flavin, which is regenerated by oxygen. This approach distinguishes from other catalytic Mitsunobu reaction procedures which require an extra catalytic system.
Bu 4 NI-Catalyzed C-C Bond Cleavage and Oxidative Esteri??cation of Allyl Alcohols with Toluene Derivatives
Chen, Yaoyao,Cui, Yongmei,Jia, Xueshun,Li, Chengliang,Li, Jian,Sun, Mingming
, p. 3667 - 3674 (2019/09/30)
A novel oxidative esterification of 1-arylprop-2-en-1-ols with toluene derivatives catalyzed by tetrabutylammonium iodide (TBAI) is reported. The optimization of the reaction conditions illustrates that each of experiment parameters including the catalyst, solvent, and oxidant is significant for present oxidative functionalization. This metal-free protocol has a broad substrate scope including the halogen groups for further functionalization and enriches the reactivity profile of allyl alcohol and toluene derivatives. In addition, this protocol represents a new transformation of allyl alcohol involving C-C bond cleavage and C-O bond forming.
Base-Promoted Amidation and Esterification of Imidazolium Salts via Acyl C-C bond Cleavage: Access to Aromatic Amides and Esters
Karthik, Shanmugam,Muthuvel, Karthick,Gandhi, Thirumanavelan
, p. 738 - 751 (2019/01/24)
Imidazolium salts have been effectively employed as suitable acyl transfer agents in amidation and esterification in organic synthesis. The weak acyl C(O)-C imidazolium bond was exploited to generate acyl electrophiles, which further react with amines and alcohols to afford amides and esters. The broad substrate scope of anilines and benzylic amines and base-promoted conditions are the benefits of this route. Interestingly, phenol, benzylic alcohols, and a biologically active alcohol can also be subjected to esterification under the optimized conditions.
Azodicarboxylate-free esterification with triphenylphosphine mediated by flavin and visible light: method development and stereoselectivity control
M?rz, Michal,Kohout, Michal,Nevesely, Tomá?,Chudoba, Josef,Pruka?a, Dorota,Niziński, Stanislaw,Sikorski, Marek,Burdziński, Gotard,Cibulka, Radek
supporting information, p. 6809 - 6817 (2018/09/29)
Triphenylphosphine (Ph3P) activated by various electrophiles (e.g., alkyl diazocarboxylates) represents an effective mediator of esterification and other nucleophilic substitution reactions. We report herein an aza-reagent-free procedure using flavin catalyst (3-methyl riboflavin tetraacetate), triphenylphosphine, and visible light (448 nm), which allows effective esterification of aromatic and aliphatic carboxylic acids with alcohols. Mechanistic study confirmed that photoinduced electron transfer from triphenylphosphine to excited flavin with the formation of Ph3P+ is a crucial step in the catalytic cycle. This allows reactive alkoxyphosphonium species to be generated by reaction of an alcohol with Ph3P+ followed by single-electron oxidation. Unexpected stereoselectivity control by the solvent was observed, allowing switching from inversion to retention of configuration during esterification of (S)- or (R)-1-phenylethanol; for example with phenylacetic acid, the ratio shifting from 10?:?90 (retention?:?inversion) in trifluoromethylbenzene to 99.9?:?0.1 in acetonitrile. Our method uses nitrobenzene to regenerate the flavin photocatalyst. This new approach to flavin re-oxidation has also been successfully proved in benzyl alcohol oxidation, which is a “standard” process among flavin-mediated photooxidations.
Atom- and Step-Economical Ruthenium-Catalyzed Synthesis of Esters from Aldehydes or Ketones and Carboxylic Acids
Runikhina, Sofiya A.,Usanov, Dmitry L.,Chizhov, Alexander O.,Chusov, Denis
supporting information, p. 7856 - 7859 (2019/01/14)
We developed a ruthenium-catalyzed reductive ester synthesis from aldehydes or ketones and carboxylic acids using carbon monoxide as a deoxygenative agent. Multiple factors influencing the outcome of the reaction were investigated. Best results were obtained for commercially available and inexpensive benzene ruthenium chloride; as low as 0.5 mol % of the catalyst is sufficient for efficient reaction. Competitive studies demonstrated that the presence of even 1000 equiv of alcohol in the reaction mixture does not lead to the corresponding ester, which clearly indicates that the process is not a simple reductive esterification but a novel type of Ru-catalyzed redox process.
Aliphatic C-H Bond Iodination by a N-Iodoamide and Isolation of an Elusive N-Amidyl Radical
Artaryan, Alexander,Mardyukov, Artur,Kulbitski, Kseniya,Avigdori, Idan,Nisnevich, Gennady A.,Schreiner, Peter R.,Gandelman, Mark
, p. 7093 - 7100 (2017/07/26)
Contrary to C-H chlorination and bromination, the direct iodination of alkanes represents a great challenge. We reveal a new N-iodoamide that is capable of a direct and efficient C-H bond iodination of various cyclic and acyclic alkanes providing iodoalkanes in good yields. This is the first use of N-iodoamide for C-H bond iodination. The method also works well for benzylic C-H bonds, thereby constituting the missing version of the Wohl-Ziegler iodination reaction. Mechanistic details were elucidated by DFT computations, and the N-centered radical derived from the used N-iodoamide, which is the key intermediate in this process, was matrix-isolated in a solid argon matrix and characterized by UV-vis as well as IR spectroscopy.
