96-43-5Relevant academic research and scientific papers
Activator free, expeditious and eco-friendly chlorination of activated arenes by N-chloro-N-(phenylsulfonyl)benzene sulfonamide (NCBSI)
Misal, Balu,Palav, Amey,Ganwir, Prerna,Chaturbhuj, Ganesh
supporting information, (2021/01/04)
N-Chloro-N-(phenylsulfonyl)benzene sulfonamide (NCBSI) has been explored for the first time as a chlorinating reagent for direct chlorination of various activated arenes and heterocycles without any activator. A comparative in-silico study was performed to determine the electrophilic character for NCBSI and commercially available N-chloro reagents to reveal the reactivity on a theoretical viewpoint. The reagent was prepared by an improved method avoiding the use of hazardous t-butyl hypochlorite. This reagent was proved to be very reactive compared to other N-chloro reagents. The precursor of the reagent N-(phenylsulfonyl)benzene sulfonamide was recovered from aqueous spent, which can be recycled to synthesize NCBSI. The eco-friendly protocol was equally applicable for the synthesis of industrially important chloroxylenol as an antibacterial agent.
Dehydroxyalkylative halogenation of C(aryl)-C bonds of aryl alcohols
Liu, Mingyang,Zhang, Zhanrong,Liu, Huizhen,Wu, Tianbin,Han, Buxing
supporting information, p. 7120 - 7123 (2020/07/14)
We herein report Cu mediated side-directed dehydroxyalkylative halogenation of aryl alcohols. C(aryl)-C bonds of aryl alcohols were effectively cleaved, affording the corresponding aryl chlorides, bromides and iodides in excellent yields. Aryl alcohols could serve as both aromatic electrophilic and radical synthetic equivalents during the reaction.
Highly-chemoselective step-down reduction of carboxylic acids to aromatic hydrocarbons: Via palladium catalysis
Liu, Chengwei,Qin, Zhi-Xin,Ji, Chong-Lei,Hong, Xin,Szostak, Michal
, p. 5736 - 5742 (2019/06/18)
Aryl carboxylic acids are among the most abundant substrates in chemical synthesis and represent a perfect example of a traceless directing group that is central to many processes in the preparation of pharmaceuticals, natural products and polymers. Herein, we describe a highly selective method for the direct step-down reduction of carboxylic acids to arenes, proceeding via well-defined Pd(0)/(ii) catalytic cycle. The method shows a remarkably broad substrate scope, enabling to direct the classical acyl reduction towards selective decarbonylation by a redox-neutral mechanism. The utility of this reaction is highlighted in the direct defunctionalization of pharmaceuticals and natural products, and further emphasized in a range of traceless processes using removable carboxylic acids under mild, redox-neutral conditions orthogonal to protodecarboxylation. Extensive DFT computations were conducted to demonstrate preferred selectivity for the reversible oxidative addition and indicated that a versatile hydrogen atom transfer (HAT) pathway is operable.
Synthesis method of 2-thiopheneacetic acid
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Paragraph 0028; 0051; 0052, (2017/01/26)
The invention provides a synthesis method of 2-thiopheneacetic acid. The synthesis method comprises the following steps: by taking thiophene as a raw material, chloridizing, iodizing, condensing with diethyl malonate, and finally hydrolyzing and heating for decarboxylation, so that 2-thiopheneacetic acid is obtained. The synthesis method provided by the invention is simple to operate, reaction process can be easily controlled, a highly toxic reagent does not need to be used, safety coefficient is high, the adopted raw material is cheap and easily available, pollution is low, requirement on production equipment is low, production cost is low, produced 2-thiopheneacetic acid is white solid powder, purity is more than or equal to 99.0%, product quality is good, and yield is high, so that the synthesis method is applicable to industrial production.
Iron(III)-mediated photocatalytic selective substitution of aryl bromine by chlorine with high chloride utilization efficiency
Wang, Ying,Li, Lina,Ji, Hongwei,Ma, Wanhong,Chen, Chuncheng,Zhao, Jincai
supporting information, p. 2344 - 2346 (2014/03/21)
An iron(III)-mediated photocatalytic method for the conversion of aryl, heteroaryl and polycyclic aromatic bromides to the corresponding chlorides with high selectivity has been achieved successfully. The mild reaction conditions and high chloride utilization efficiency promise a bright future for chlorination reactions. The Royal Society of Chemistry 2014.
Halogenation of Aromatic Compounds by N-chloro-, N-bromo-, and N-iodosuccinimide
Tanemura, Kiyoshi,Suzuki, Tsuneo,Nishida, Yoko,Satsumabayashi, Koko,Horaguchi, Takaaki
, p. 932 - 933 (2007/10/03)
An efficient and mild method for the halogenation of aromatic compounds using N-chloro-, N-bromo-, and N-iodosuccinimide in the presence of NH 4NO3 or FeCl3 in acetonitrile was developed.
A convenient catalytic route to symmetrical functionalized bithiophenes
Hassan, Jwanro,Lavenot, Laurence,Gozzi, Christel,Lemaire, Marc
, p. 857 - 858 (2007/10/03)
A series of symmetrical functionalized bithiophenes has been synthesized in good to excellent yields via homocoupling of thiophene halides in the presence of Pd(OAc)2 as a catalyst.
Competitive reactivities of vinylthiyl radicals thermally generated from haloethylenes and hydrogen sulfide
Deryagina,Sukhomazova,Levanova
, p. 662 - 666 (2007/10/03)
Acetylene and its derivatives have been used for the first time as "traps" for vinylthiyl radicals generated in situ from hydrogen sulfide and haloethylenes in gas-phase processes. The competitive reactivity of the vinylthiyl radicals has been studied at 500-570 °C in the presence of two chemical "traps." The efficiency of chemical "traps" for the vinylthiyl radicals decreases in the following sequence: HC≡CPh > HC≡CH > MeC≡CH > CH2=CHCl. Acetylene is a more efficient "trap" for the vinylthiyl radicals than 1,2-dichloroethylene, from which they have been generated. The β-phenylvinylthiyl radicals generated during cothermolysis of halostyrene-hydrogen sulfide-acetylene component ternary systems undergo first of all intramolecular ring closure to give benzothiophene, which is a thermodynamically favorable system; the reaction of these radicals with acetylene and its derivatives occurs much more slowly than heterocyclization. Phenylacetylene is a more efficient "trap" than acetylene. α-Phenylvinylthiyl radicals mostly react with acetylene to yield 2-phenylthiophene.
Reevaluation of benzyltrimethylammonium dichloroiodide, previously reported to be a selective iodinating agent
D'Auria,Mauriello
, p. 248 - 250 (2007/10/02)
Benzyltrimethylammonium dichloroiodate, previously reported as an iodinating agent of thiophenes, appears to be a selective chlorinating agent of both thienyl and furyl derivatives containing a carbonyl group.
Nickel catalyst for the cyanation of aromatic halides
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, (2008/06/13)
The invention relates to a nickel compound to be used as a catalyst for cyanation reactions, said nickel compound having a central nickel atom complexed by a diphosphine ligand. In said diphosphine ligand the P-atoms are interconnected through an aliphatic, cycloaliphatic or aromatic bivalent radical. The invention also relates to the use of said nickel compound and to a method of preparing an aromatic cyanide from an aromatic halide and an alkali metal cyanide in a substantially anhydrous non-dipolar aprotic solvent under the influence of a phosphine-nickel catalyst and in the presence of a salt of a transition metal.
