3328-86-7Relevant academic research and scientific papers
β-Bromoenol phosphate as a new precursor for the modular regioselective synthesis of substituted furans
Fernandes, Rushil,Mhaske, Krishna,Narayan, Rishikesh
, (2021/11/24)
Owing to its importance in various realms of chemistry, furan occupies a position of eminence among heterocycles. Despite the availability of many methodologies for the synthesis of variably substituted furans, a modular convenient synthesis of 2,4-disubstituted furans remains challenging. The present work attempts to bridge that gap through a novel annulation-based approach using feedstock chemicals such as methyl ketones and their easily available derivatives, β-bromoenol phosphates. We have demonstrated a hitherto unknown reactivity of β-bromoenol phosphates which is responsible for the observed regioselectivity. The reaction requires only sodium hydride as the base under mild conditions. The scope of the reaction was found to be broad with the possibility of obtaining even tri-substituted furans besides a variety of 2,4-disubstituted furans. The methodology was applied to obtain synthetically challenging 3-acylfuran derivatives as well. The newly developed methodology is characterized by the modularity, regioselectivity as well as its practicality owing to easily available starting materials and fast reaction times.
Cu-catalyzed [2 + 2 + 1] cascade annulation of vinyl iodonium salts with elemental sulfur/selenium for the modular synthesis of thiophenes and selenophenes
Chen, Chao,Wang, Fei,Wu, Chao,Wu, Yaxing
, p. 945 - 949 (2022/02/01)
A [2 + 2 + 1] annulation protocol has been established for the modular synthesis of 2,4-disubstituted thiophenes/selenophenes, with excellent regioselectivity. The reactions have been catalyzed by copper salt with elemental sulfur and selenium serving as
Efficient Thiophene Synthesis Mediated by 1,3-Bis(carboxymethyl)imidazolium Chloride: C-C and C-S Bond Formation
Gisbert, Patricia,Pastor, Isidro M.
, p. 4319 - 4325 (2020/07/16)
Thiophene derivatives have been prepared by means of a functionalized imidazolium salt [1,3-bis(carboxymethyl)imidazolium chloride] acting as a catalyst. The heterogeneous catalyst has allowed to carry out the reactions with no solvent or inert atmosphere
Sulfurative self-condensation of ketones and elemental sulfur: A three-component access to thiophenes catalyzed by aniline acid-base conjugate pairs
Nguyen, Thanh Binh,Retailleau, Pascal
supporting information, p. 387 - 390 (2018/02/07)
A sulfurative self-condensation method for constructing thiophenes 2 by a reaction between ketones 1 and elemental sulfur is reported. This reaction, which is catalyzed by anilines and their salts with strong acids, starts from readily available and inexp
Transition-Metal-Free Sulfuration/Annulation of Alkenes: Economical Access to Thiophenes Enabled by the Cleavage of Multiple C-H Bonds
Chen, Liang,Min, Hao,Zeng, Weilan,Zhu, Xiaoming,Liang, Yun,Deng, Guobo,Yang, Yuan
, p. 7392 - 7395 (2019/01/03)
A novel, atom economical, and transition-metal-free strategy for the synthesis of thiophenes from substituted buta-1-enes with potassium sulfide has been presented. The reaction achieves double C-S bond formations via cleavage of multiple C-H bonds and provides an efficient approach to access various functionalized thiophenes. Moreover, the strategy can also be used for the synthesis of thiophenes from 1,4-diaryl-1,3-dienes. Mechanistically, DMSO plays a role of oxidant and S3?- in situ generated from K2S is involved.
Palladium-catalyzed dehydrogenative coupling of cyclic enones with thiophenes: A rapid access to β-heteroarylated cyclic enones
Wen, Zhen-Kang,Song, Ting-Ting,Liu, Yu-Fang,Chao, Jian-Bin
supporting information, p. 3668 - 3671 (2018/04/12)
Dehydrogenative coupling of cyclic enones with heteroarenes has been a longstanding challenge because of the competitive ketone dehydrogenation and conjugated addition. Herein, a dehydrogenative coupling reaction of cyclic enones of different sizes with substituted thiophenes to construct β-thienyl cyclic enone compounds through palladium-catalyzed C-H functionalization under mild reaction conditions is reported. Simple substituted thiophenes with different functional groups can be directly introduced into cyclic enones with predominant regioselectivity at the α position of thiophene moieties and excellent functional group tolerance. Further molecular transformations of the coupling products to synthetically useful meta-heteroarylated phenol derivatives have also been demonstrated.
Method for catalyzing terminal alkene and powdered sulfur with copper to react in water phase to generate thiophene ring
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Paragraph 0004; 0022, (2016/10/10)
The invention discloses a method for catalyzing terminal alkene and powdered sulfur to react in a pure water phase to prepare a thiophene derivative. A water-soluble complex is used as a catalyst, and a one-pot reaction is conducted in the pure water phas
Selective β-Arylation of Thiophenes with Aryl Iodides Catalyzed by Dinuclear Palladium Carboxylate Complexes
Maki, Yohei,Goto, Takahiro,Tsukada, Naofumi
, p. 699 - 702 (2016/03/05)
Novel dinuclear palladium complexes bearing acetoxy ligands were synthesized and characterized by X-ray crystal analysis. The complexes were utilized for the arylation of 2-ethylthiophene with iodobenzene to give ethylphenylthiophenes with high β selectiv
Kinetic Studies on the Palladium(II)-Catalyzed Oxidative Cross-Coupling of Thiophenes with Arylboron Compounds and Their Mechanistic Implications
Schnapperelle, Ingo,Breitenlechner, Stefan,Bach, Thorsten
supporting information, p. 18407 - 18416 (2015/12/24)
Reaction orders for the key components in the palladium(II)-catalyzed oxidative cross-coupling between phenylboronic acid and ethyl thiophen-3-yl acetate were obtained by the method of initial rates. It turned out that the reaction rate not only depended on the concentration of palladium trifluoroacetate (reaction order: 0.97) and phenylboronic acid (reaction order: 1.26), but also on the concentration of the thiophene (reaction order: 0.55) and silver oxide (reaction order: -1.27). NMR spectroscopy titration studies established the existence of 1:1 complexes between the silver salt and both phenylboronic acid and ethyl thiophen-3-yl acetate. A low inverse kinetic isotope effect (kH/kD=0.93) was determined upon employing the 4-deuterated isotopomer of ethyl thiophen-3-yl acetate and monitoring its reaction to the 4-phenyl-substituted product. A Hammett analysis performed with para-substituted 2-phenylthiophenes gave a negative ρ value for oxidative cross-coupling with phenylboronic acid. Based on the kinetic data and additional evidence, a mechanism is suggested that invokes transfer of the phenyl group from phenylboronic acid to a 1:1 complex of palladium trifluoroacetate and thiophene as the rate-determining step. Proposals for the structure of relevant intermediates are made and discussed.
In-Depth Assessment of the Palladium-Catalyzed Fluorination of Five-Membered Heteroaryl Bromides
Milner, Phillip J.,Yang, Yang,Buchwald, Stephen L.
supporting information, p. 4775 - 4780 (2015/10/28)
A thorough investigation of the challenging Pd-catalyzed fluorination of five-membered heteroaryl bromides is presented. Crystallographic studies and density functional theory (DFT) calculations suggest that the challenging step of this transformation is
