17847-33-5Relevant academic research and scientific papers
Conversion of esters to thioesters under mild conditions
Shi, Yijun,Liu, Xuejing,Cao, Han,Bie, Fusheng,Han, Ying,Yan, Peng,Szostak, Roman,Szostak, Michal,Liu, Chengwei
supporting information, p. 2991 - 2996 (2021/04/14)
We report conversion of esters to thioestersviaselective C-O bond cleavage/weak C-S bond formation under transition-metal-free conditions. The method is notable for a general and practical transition-metal-free system, broad substrate scope and excellent functional group tolerance. The strategy was successfully deployed in late-stage thioesterification, site-selective cross-coupling/thioesterification/decarbonylation and easy-to-handle gram scale thioesterification. Selectivity and computational studies were performed to gain insight into the formation of weak C-S bonds by C-O bond cleavage, which contrasts with the traditional trend of nucleophilic additions to carboxylic acid derivatives.
Cu(II)-silsesquioxanes as efficient precatalysts for Chan-Evans-Lam coupling
Astakhov, G. S.,Bantreil, X.,Bilyachenko, A. N.,Dorovatovskii, P. V.,Khrustalev, V. N.,Lamaty, F.,Levitsky, M. M.,Shubina, E. S.,Zubavichus, Y. V.
, (2019/11/28)
Two cage copper(II)silsesquioxanes, namely, tricopper complex (PhSiO1.5)8(CuO)3(TMEDA)2*(MeCN)3 Cu-1 and hexacopper complex (MeSiO1,5)12(CuO)6(Py)6*TMEDA Cu
Acyl Cyanides as Bifunctional Reagent: Application in Copper-Catalyzed Cyanoamidation and Cyanoesterification Reaction
Chen, Zhengwang,Wen, Xiaowei,Zheng, Weiping,He, Ruolan,Chen, Dou,Cao, Dingsheng,Long, Lipeng,Ye, Min
, p. 5691 - 5701 (2020/04/10)
Cu-catalyzed domino decyanation and cyanation reaction of acyl cyanides with amines or alcohols have been developed. The cyano sources were generated in situ via C-CN cleavage yielding the corresponding cyano substituted amides or esters in moderate to excellent yields. This approach features a cheap copper catalyst, domino decyanation and cyanation reaction, readily available starting materials, broad substrate scope, operational simplicity, and the potential for further transformation of the cyano group.
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.
Nickel-Catalyzed Decarbonylative Cyanation of Acyl Chlorides
Wang, Zhenhua,Wang, Xiu,Ura, Yasuyuki,Nishihara, Yasushi
, p. 6779 - 6784 (2019/08/26)
Ni-catalyzed decarbonylative cyanation of acyl chlorides with trimethylsilyl cyanide has been achieved. This transformation is applicable to the synthesis of an array of nitrile compounds bearing a wide range of functional groups under neutral conditions. The step-by-step experimental studies revealed that the reaction sequences of the present catalytic reaction are oxidative addition, transmetalation, decarbonylation, and reductive elimination.
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.
Oxime palladacycle in PEG as a highly efficient and recyclable catalytic system for phenoxycarbonylation of aryl iodides with phenols
Gaikwad, Vinayak V.,Bhanage, Bhalchandra M.
, (2019/02/19)
In this report, we have developed a sustainable protocol for the synthesis of aromatic esters by a carbonylative method using di-μ-chlorobis [5-hydroxy-2-[1-(hydroxyimino-?N) ethyl] phenyl-?C] palladium (II) dimer (1) catalyst in PEG-400 as a greener and recyclable solvent. The reaction is carried out at room temperature using CO in a balloon. Good to excellent yield of various esters can be synthesize using this protocol. Direct insertion of CO moiety leads to the high atom and step economy. Compared to previous protocol this phosphine free approach for the synthesis of aromatic esters provides high Turnover Number (TON) and Turnover Frequency (TOF). Developed approach has an alternative route for use of conventional palladium precursor with high conversion and selectivity. The catalyst system and product can easily be separated using diethyl ether as a solvent. The Pd/PEG-400 system could be reused up to a fifth consecutive cycle without any loss of its activity and selectivity.
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.
Mechanistic Insight into Weak Base-Catalyzed Generation of Carbon Monoxide from Phenyl Formate and Its Application to Catalytic Carbonylation at Room Temperature without Use of External Carbon Monoxide Gas
Konishi, Hideyuki,Matsubara, Mika,Mori, Keisuke,Tokiwa, Takaki,Arulmozhiraja, Sundaram,Yamamoto, Yuta,Ishikawa, Yoshinobu,Hashimoto, Hiroshi,Shigeta, Yasuteru,Tokiwa, Hiroaki,Manabe, Kei
supporting information, p. 3592 - 3601 (2017/10/24)
The mechanisms of the weak base-catalyzed generation of carbon monoxide (CO) and phenol from phenyl formate were investigated by experimental and theoretical methods. Kinetic studies revealed a first-order reaction in both phenyl formate and the base. The reaction was found to proceed by an E2 α-elimination pathway, which involves the abstraction of the formyl proton of phenyl formate, simultaneously generating CO and phenoxide. The reaction rate was affected by the substituents on phenyl formate, the polarity of solvents, and the basicity of bases. The mechanistic insight obtained from these studies permitted the chemical control of the rate of CO generation, which was the key to the development of the external CO-free Pd-catalyzed phenoxycarbonylation of haloarenes at room temperature. Because of the mild reaction conditions and wide substrate scope, this phenoxycarbonylation constitutes a general, safe, and practical method to synthesize arenecarboxylic acid esters. (Figure presented.).
Pd/C catalyzed phenoxycarbonylation using: N -formylsaccharin as a CO surrogate in propylene carbonate, a sustainable solvent
Gautam, Prashant,Kathe, Prasad,Bhanage, Bhalchandra M.
supporting information, p. 823 - 830 (2017/08/15)
This work reports the first Pd/C catalyzed phenoxycarbonylation of aryl iodides using N-formylsaccharin as a CO surrogate. Advantageously, the reaction could be carried out in propylene carbonate, an environmentally benign and sustainable polar aprotic solvent under CO surrogacy. Using N-formylsaccharin as a CO surrogate allows the usage of cheaper and readily available phenols as the coupling partner. A range of phenyl esters could be synthesized under mild, co-catalyst free, ligand free and additive free conditions, including multi-substituted novel phenyl esters. The Pd/C catalyst could be recycled up to four times with only a slight loss in activity. The reaction could be scaled up to gram scale synthesis.
