41998-14-5Relevant academic research and scientific papers
Transition-Metal-Free DMAP-Mediated Aromatic Esterification of Amides with Organoboronic Acids
Guo, Jiarui,Liu, Lantao,Wang, Tao,Wang, Yanqing,Xu, Kai,Zhang, Yuheng
supporting information, p. 3274 - 3277 (2021/06/26)
A new, transition-metal-free, effective method for aromatic esterification of amides with organoboronic acids has been developed. A wide range of benzoate derivatives were obtained with yields ranging from moderate to good. The catalytic reaction shows a broad substrate scope and excellent functional group tolerance. Conceptually, DMAP mediates the reaction and is crucial for this transformation.
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.]
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
Ester Transfer Reaction of Aromatic Esters with Haloarenes and Arenols by a Nickel Catalyst
Inayama, Naomi,Isshiki, Ryota,Muto, Kei,Yamaguchi, Junichiro
, p. 3490 - 3494 (2020/03/23)
A catalytic ester transfer reaction of aromatic esters with aryl halides/arenols was developed. The present reaction can transfer an ester functional group from certain aromatic esters to haloarenes. This ester transfer reaction involves two oxidative additions-one from the C-C bond of the aromatic ester and one from the C-halogen bond of haloarenes-onto a nickel catalyst. The utilization of a Ni/dcypt catalyst capable of cleaving both chemical bonds was a key for the reaction progress. Furthermore, naphthol-based aryl electrophiles were also applicable to the catalytic system via C-O bond activation.
Palladium-catalyzed aryloxy- and alkoxycarbonylation of aromatic iodides in γ-valerolactone as bio-based solvent
Tukacs, József M.,Marton, Bálint,Albert, Eszter,Tóth, Imre,Mika, László T.
, (2020/08/11)
Fossil-based solvents and triethylamine as a toxic and volatile base were successfully replaced with γ-valerolactone as a non-volatile solvent and K2CO3 as inorganic base in the alkoxy- and aryloxycarbonylation of aryl iodides using phosphine-free Pd catalyst systems. By this, the traditional systems were not simply replaced but also significantly improved. In the study, the effects of different reaction parameters, i.e. the use of several other solvents, the temperature, the carbon monoxide pressure, the base and the catalyst concentrations, were evaluated in details on the efficiency of the carbonylations. To gather some information on the mechanism of these reactions, the effects of the electronic parameters (σ) of various aromatic substituents of the aryl iodides as well as the influence of para-substitution of phenol were investigated on the activity. For a comparison, the aryl-substituted aryl iodides were also reacted with methanol and aryl iodide was also alkoxycarbonylated using several different lower alcohols. From the observed correlations between the electronic parameters of the aromatic substituents and the rates, it appears that the rate determining step is the oxidative addition of Ar–I to Pd0, provided that sufficient amounts of nucleophiles are present for the ester formation. If this is not the case, the rate of nucleophile attack might determine the overall rate.
Palladium-Catalyzed Aerobic Oxidative Coupling of Amides with Arylboronic Acids by Cooperative Catalysis
Li, Yue,Wu, Hongxiang,Zeng, Zhuo
supporting information, p. 4357 - 4361 (2019/07/09)
The first fluoride and palladium co-catalyzed conversion of amide to ester through an aerobic oxidative coupling pathway is reported. This new approach presents a practical process that employs easily available oxygen and commercially available arylboronic acids as coupling partners, uses a wide range of N- tosylamides, and proceeds under mild reaction conditions. This protocol demonstrates broad functional group tolerance, and provides an alternative option to synthesize esters from N-tosylamides which obtained by simply N-functionalization of secondary amides.
Nickel-Catalyzed Cross-Coupling of Aryl Redoxactive Esters with Aryl Zinc Reagents
Shih, Bo-Hao,Basha, R. Sidick,Lee, Chin Fa
, p. 8862 - 8866 (2019/09/30)
A nickel-catalyzed aryl-aroyloxyl C(sp2)-O radical cross-coupling reaction conducted using a redox active ester with aryl zinc reagent was developed. This method demonstrates a new disconnection approach for formation of aryl aryl esters. In the one-pot sequential process, the readily available aryl carboxylic acids can be converted into functionalized aryl aryl esters and heteroaryl esters. This protocol is amenable to the gram-scale synthesis. The present method has a wide substrate scope and high functional group tolerance.
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.
Transesterification of (hetero)aryl esters with phenols by an Earth-abundant metal catalyst
Chen, Jianxia,Namila,Bai, Chaolumen,Baiyin, Menghe,Agula, Bao,Bao, Yong-Sheng
, p. 25168 - 25176 (2018/07/29)
Readily available and inexpensive Earth-abundant alkali metal species are used as efficient catalysts for the transesterification of aryl or heteroaryl esters with phenols which is a challenging and underdeveloped transformation. The simple conditions and the use of heterogeneous alkali metal catalyst make this protocol very environmentally friendly and practical. This reaction fills in the missing part in transesterification reaction of phenols and provides an efficient approach to aryl esters, which are widely used in the synthetic and pharmaceutical industry.
Palladium-Catalyzed Oxidative Carbonylation of Aryl Hydrazines with CO and O2 at Atmospheric Pressure
Tu, Yongliang,Yuan, Lin,Wang, Tao,Wang, Changliu,Ke, Jiamei,Zhao, Junfeng
, p. 4970 - 4976 (2017/05/12)
Palladium-catalyzed aerobic oxidative aminocarbonylation and alkoxycarbonylation reactions with aryl hydrazines as coupling partners have been developed. The oxidative carbonylation of aryl hydrazines proceeded smoothly at atmospheric pressure CO, employi
