41013-94-9Relevant academic research and scientific papers
Switching between mono and doubly reduced odd alternant hydrocarbon: designing a redox catalyst
Ahmed, Jasimuddin,Datta, Paramita,Das, Arpan,Jomy, Stephy,Mandal, Swadhin K.
, p. 3039 - 3049 (2021/03/14)
Since the early Hückel molecular orbital (HMO) calculations in 1950, it has been well known that the odd alternant hydrocarbon (OAH), the phenalenyl (PLY) system, can exist in three redox states: closed shell cation (12π e?), mono-reduced open shell neutral radical (13π e?) and doubly reduced closed shell anion (14π e?). Switching from one redox state of PLY to another leads to a slight structural change owing to its low energy of disproportionation making the electron addition or removal process facile. To date, mono-reduced PLY based radicals have been extensively studied. However, the reactivity and application of doubly reduced PLY species have not been explored so far. In this work, we report the synthesis of the doubly reduced PLY species (14π e?) and its application towards the development of redox catalysisviaswitching with the mono-reduced form (13π e?) for aryl halide activation and functionalization under transition metal free conditions without any external stimuli such as heat, light or cathodic current supply.
METHOD FOR SYNTHESIZING BORONATE ESTER COMPOUND, SODIUM SALT OF BORONATE ESTER COMPOUND, AND METHOD FOR SYNTHESIZING THE SAME
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, (2021/03/13)
An object is to establish a technology with which a boronate ester compound can be easily and efficiently synthesized at a low cost with a small number of steps without the need for a complex chemical method and reagents that need to be carefully handled. A further object is to establish a sodium salt of a boronate ester compound that is a novel compound and a technology for synthesizing the sodium salt of a boronate ester compound. Provided are a sodium salt of a boronate ester compound and a method for synthesizing a boronate ester compound or a sodium salt of a boronate ester compound that includes reacting, in a reaction solvent, an organic chloride with a dispersion product obtained by dispersing sodium in a dispersion solvent to obtain an organic sodium compound, and reacting the obtained organic sodium compound with a borate ester compound to obtain a boronate ester compound or a sodium salt of a boronate ester compound.
Acid-promoted selective synthesis of trifluoromethylselenolated benzofurans with Se-(trifluoromethyl) 4-methylbenzenesulfonoselenoate
Liu, Juyan,Tian, Miaomiao,Li, Ankun,Ji, Liangshuo,Qiu, Di,Zhao, Xia
supporting information, (2021/02/01)
A Br?nsted acid-promoted trifluoromethylselenolation of benzofurans was disclosed by using Se-(trifluoromethyl) 4-methylbenzenesulfonoselenoate as a stable and easily prepared electrophilic trifluoromethylselenolating reagent. A wide range of SeCF3-substituted benzofuran derivatives were obtained in moderate to good yields with excellent regioselectivity. The tandem cyclization/trifluoromethylselenolation procedure of 1-methoxy-2-(arylethynyl)benzenes were also realized by engaging FeCl3 as the catalyst.
Transition-Metal-Free Synthesis of Heterobiaryls through 1,2-Migration of Boronate Complex
Paul, Swagata,Das, Kanak Kanti,Manna, Samir,Panda, Santanu
, p. 1922 - 1927 (2020/02/04)
The synthesis of a diverse range of heterobiaryls has been achieved by a transition-metal-free sp2–sp2 cross-coupling strategy using lithiated heterocycle, aryl or heteroaryl boronic ester and an electrophilic halogen source. The construction of heterobiaryls was carried out through electrophilic activation of the aryl–heteroaryl boronate complex, which triggered 1,2-migration from boron to the carbon atom. Subsequent oxidation of the intermediate boronic ester afforded heterobiaryls in good yield. A comprehensive 11B NMR study has been conducted to support the mechanism. The cross coupling between two nucleophilic cross coupling partners without transition metals reveals a reliable manifold to procure heterobiaryls in good yields. Various heterocycles like furan, thiophene, benzofuran, benzothiophene, and indole are well tolerated. Finally, we have successfully demonstrated the gram scale synthesis of the intermediates for an anticancer drug and OLED material using our methodology.
Unexpected detection of 3-aroylbenzofuran side products in the preparation of 2-arylbenzofurans: Identification, characterization, and comparison with chalcone's fragmentation patterns using EI/MSn
Begala, Michela,Delogu, Giovanna Lucia
, p. 750 - 760 (2019/09/03)
A gas chromatography-mass spectrometry study of the intramolecular Wittig reaction revealed, together with the expected 2-phenylbenzofuran, the formation of an unexpected side product that has not been reported until now. This study reports the identification of the by-product, ie, the 3-benzoyl-2-phenylbenzofuran, on the base of its mass spectrometric behaviour using a combination of electron ionization, exact mass measurement, multiple stage mass spectrometry, and labelled compounds. This study reports the common fragmentation pathways and discusses possible fragment structures of characteristic ions from a series of 3-aroyl-2-arylbenzofuran derivatives obtained as by-product under Wittig conditions. Emphasis is laid on the formation and structure investigation of the [M-H]+ and [M-OH]+ ions. Our results showed interesting analogies with the mass spectrometric behaviour of chalcones.
Unexpected one-step synthesis of 3-benzoyl-2-phenylbenzofurans under Wittig conditions
Begala, Michela,Caboni, Pierluigi,Matos, Maria Jo?o,Delogu, Giovanna Lucia
, p. 1711 - 1714 (2018/04/10)
The reaction of 2-hydroxybenzyltriphenylphosphonium bromide with substituted benzoyl chlorides under Wittig conditions, led to 2-phenylbenzofuran derivatives 4a–p and the unexpected formation of 3-benzoyl-2-phenylbenzofuran derivatives 5a–p. Benzoyl chlorides possessing electron-withdrawing groups afforded 3-benzoyl-2-phenylbenzofuran derivatives in higher yields than those with electron-donating groups. This reaction represents a simple and regioselective, one-pot route towards the preparation of deactivated 3-benzoyl-2-phenylbenzofuran compounds which are difficult to obtain by the direct acylation of 2-phenylbenzofurans.
Hydrazone-Pd-catalyzed direct intermolecular reaction of: O -alkynylphenols with allylic acetates
Watanabe, Kohei,Mino, Takashi,Ishikawa, Eri,Masuda, Chihiro,Yoshida, Yasushi,Sakamoto, Masami
, p. 575 - 584 (2018/02/07)
We found that the hydrazone-Pd-catalyzed direct intermolecular reaction of o-alkynylphenols with allylic acetates afforded the corresponding 2-substituted-3-allylbenzofuran derivatives. This reaction proceeded smoothly at room temperature using a hydrazon
Method for synthesizing benzofuranol derivative by nickel-catalysis of phenethynyl phenol under microwave irradiation
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Paragraph 0025; 0053, (2018/09/11)
The invention discloses a method for synthesizing a benzofuranol derivative by nickel-catalysis of phenethynyl phenol under microwave irradiation; a catalytic amount of catalyst nickel chloride, ligand 1,10-phenanthroline(1,10-Phen), auxiliary catalyst po
Catalytic Intramolecular Wittig Reaction Based on a Phosphine/Phosphine Oxide Catalytic Cycle for the Synthesis of Heterocycles
Wang, Long,Sun, Mei,Ding, Ming-Wu
, p. 2568 - 2578 (2017/05/19)
The catalytic intramolecular Wittig reactions of carbonyl-containing bromides are reported. The R3PO byproducts participate in the catalytic cycle; therefore, the Wittig reaction can be accomplished with only a catalytic amount of organophosphorus reagent. The reaction has also been applied to the efficient and selective synthesis of isoquinolin-1(2H)-ones, indoles, 2,3-dihydro-1H-2-benzazepin-1-ones, benzofurans, and 1,2-dihydroquinolines with a catalytic amount of phosphine oxide (0.1 equiv.) and a tetramethyldisiloxane/titanium isopropoxide [TMDS/Ti(OiPr)4] reductant system (yields: 35–88 %).
Direct C–H Arylation of Heteroarenes with Aryl Chlorides by Using an Abnormal N-Heterocyclic-Carbene–Palladium Catalyst
Ahmed, Jasimuddin,Sau, Samaresh Chandra,Sreejyothi,Hota, Pradip Kumar,Vardhanapu, Pavan K.,Vijaykumar, Gonela,Mandal, Swadhin K.
supporting information, p. 1004 - 1011 (2017/02/15)
Herein, we report a versatile catalytic system for the direct C–H arylation of heteroarenes with activated aryl chloride substrates. The catalyst works successfully for a variety of heteroarenes and aryl chloride coupling partners under very low catalyst-loading conditions. We have successfully performed the direct C–H arylations of 1-methylpyrrole, 1-methylindole, furan, thiophene, furfural, and N-benzyl-1,2,3-triazole with aryl chloride partners in good yields without the use of any additives. Furthermore, we used this catalytic process to develop a one-pot synthetic protocol for the muscle relaxant dantrolene on a gram scale. Additionally, the present catalytic system can be used to perform consecutive arylations in one pot.
