63697-19-8Relevant academic research and scientific papers
Direct Stereoselective β-Arylation of Enol Ethers by a Decarboxylative Heck-Type Reaction
Hachem, Mahmoud,Hoarau, Christophe,Schneider, Cédric
, (2020/04/15)
Despite remarkable advances to promote regio- and stereoselective decarboxylative arylation of inactivated olefins with benzoic acid derivatives, methodologies involving hetero-substituted alkenes are still lacking. Herein, PdII-catalyzed decarboxylative Heck coupling of α-alkoxyacrylates with (hetero)aryl carboxylic acids for the stereocontrolled production of (Z)-β-heteroarylated vinyl ethers is reported. This methodology offers a rational and step-economical route to the synthesis of attractive β-arylated α-alkoxy α,β-unsaturated carboxylates family which emerged as a relevant class of building blocks with different applications. Mechanistically, whereas electron rich benzoic acids undergo a PdII-catalyzed decarboxylation, electron-deficient substrates proceed through silver(I)-mediated decarboxylation, explaining thus the formation of stereoisomers (E) and (Z) of β-arylated vinyl ethers in presence of these latter.
Iron(iii)porphyrin electrocatalyzed enantioselective carbon-chloride bond cleavage of hexachlorocyclohexanes (HCHs): Combined experimental investigation and theoretical calculations
Liang, Xu,Li, Minzhi,Mack, John,Lobb, Kevin,Zhu, Weihua
, p. 11470 - 11476 (2018/08/28)
Enantioselective electrocatalysis of α-, β-, γ- and δ-hexachlorocyclohexanes (HCHs) by tetrakis-pentafluorophenyl-Fe(iii)porphyrin is described. The first example of the combined use of electrochemical measurements and theoretical calculations to determine the mechanism of the enantioselective C-Cl bond cleavage of the electrocatalysis is reported. The electrochemical measurements demonstrate that the reactivity of the HCHs follows the order γ-HCH > α-HCH > δ-HCH > β-HCH. Steric considerations and a molecular orbital theory approach can be used to rationalize the enantioselective nature of the catalysis based on the ease of approach of each Cl atom to the central Fe(i) ion and a consideration of the nodes on the C-Cl bonds that weaken these bonds in a manner that results in bond cleavage and the formation of an Fe-Cl bond.
Visible light driven hydro-/deuterodefunctionalization of anilines
Majek, Michal,Filace, Fabiana,Von Wangelin, Axel Jacobi
supporting information, p. 4518 - 4522 (2015/03/18)
The defunctionalization of anilines is an important strategy in aromatic-substitution chemistry. Herein, we report on visible light mediated hydro- and deuterodediazonations in solutions of DMF. The mild reaction conditions (DMF, RT, no additives) tolerate various functional groups and allow the site-specific introduction of D atoms to the arene. Mechanistic investigations indicate the participation of photoredox and radical chain pathways and competing abstraction of methyl and formyl hydrogen atoms from DMF.
Electroreductive dechlorination of α-hexachlorocyclohexane catalyzed by iron porphyrins in nonaqueous media
Zhu, Weihua,Ni, Cui,Liang, Lili,Li, Junwen,Li, Minzhi,Ou, Zhongping,Kadish, Karl M.
, p. 519 - 527 (2014/07/21)
Two iron porphyrins, (TPP)FeCl and (OEP)FeCl, where TPP and OEP are the dianions of tetraphenylporphyrin and octaethylporphyrin, respectively, were utilized as catalysts for the electroreductive dechlorination of α-hexachlorocyclohexane (α-HCH) which was monitored by electrochemistry, in situ UV-visible spectroelectrochemistry and controlled potential electrolysis in N,N′-dimethylformamide. GC-MS analysis of the α-HCH degradation products revealed the stepwise formation of pentachlorocyclohexene and tetrachlorocyclohexadiene as intermediates, prior to generation of the final dechlorination products which consisted of an isomeric mixture of trichlorobenzenes. Based on identification of the intermediates and final products in the reaction, an overall dechlorination mechanism of α-hexachlorocyclohexane is proposed.
Base-promoted protodeboronation of 2,6-disubstituted arylboronic acids
Lozada, Jerome,Liu, Zhibo,Perrin, David M.
supporting information, p. 5365 - 5368 (2014/06/23)
Facile based promoted deboronation of electron-deficient arylboronate esters was observed for arylboronates containing two ortho electron-withdrawing group (EWG) substituents. Among 30 representative boronates, only the diortho-substituted species underwe
Chlorination of aniline and methyl carbanilate by N-chlorosuccinimide and synthesis of 1,3,5-trichlorobenzene
Davis, Matthew C.
experimental part, p. 1100 - 1108 (2009/09/08)
Aniline undergoes regioselective trichlorination by N-chlorosuccinimide (NCS) in acetonitrile in good yield. The product 2,4,6-trichoroaniline was converted into 1,3,5-trichlorobenzene by reduction of its diazonium salt. Reaction of the methyl carbamate of aniline with NCS gave only the 2,4-dichlorophenyl carbamate. Copyright Taylor & Francis Group, LLC.
Formation and destruction of chlorinated pollutants during sewage sludge incineration
Fullana, Andres,Conesa, Juan A.,Font, Rafael,Sidhu, Sukh
, p. 2953 - 2958 (2007/10/03)
The limitations facing land filling and recycling and the planned ban on sea disposal of sludge leads to the expectation that the role of sludge incineration will increase in the future. The expected increase in sludge incineration will also increase scrutiny of the main drawback to sewage sludge incineration-the formation of hazardous air pollutants (HAPs). Despite the extensive body of knowledge available on sewage sludge combustion, very few studies have been conducted on the formation of HAPs during sludge combustion. In this work, the interactions between sewage sludge pyrolysis products and sludge ash were investigated using a dual chamber flow reactor system and a horizontal laboratory scale reactor. The results of this study shows that sludge ash can catalyze oxidation and chlorination of organics. In the absence of HCl in the gas stream, sludge ash acts as an oxidizing catalyst, but in the presence of HCl, sludge ash acts as a chlorination catalyst producing high yields of organochloride compounds.
Effects of FeS on the transformation kinetics of γ-hexachlorocyclohexane
Liu, Xiangmei,Peng, Ping'an,Fu, Jiamo,Huang, Weilin
, p. 1822 - 1828 (2007/10/03)
Distinctly different rates and pathways were observed for abiotic transformation of γ-hexachlorocyclohexane (γHCH) between homogeneous systems and systems containing FeS solid. The observed half-lives of γ-HCH decrease from about 1136 and 126 d in homogen
A newly developed synthesis of 1,3,5-trichlorobenzene (sym. TCB) from aniline
Mehilal,Salunke,Agrawal
, p. 604 - 607 (2007/10/03)
1,3,5-Trichlorobenzene (sym. TCB) has been synthesised by diazotisation of 2,4,6-trichloroaniline (sym. TCA) (by converting aniline into anilinium chloride followed by its chlorination) in the presence of H2SO4/NaNO2 and H3PO2. The reaction parameters for the synthesis of both sym, TCA as well as sym. TCB have also been established in order to get better purity and higher yields, sym. TCA and sym. TCB have been characterized by elemental analysis, Fourier Transform Infra Red (FTIR) and NMR spectroscopy. Further, different reaction parameters for the nitration of sym. TCB to get 1,3,5- trichloro-2,4,6-trinitrobenzene (TCTNB) and its amination to get pure 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) have also been established. A comparison of properties of TATB obtained from imported sym. TCB and from laboratory prepared sym. TCB validates the product.
1-Aryl-3,3-dialkyltriazenes: A convenient synthesis from dry arenediazonium o-benzenedisulfonimides - A high yield break down to the starting dry salts and efficient conversions to aryl iodides, bromides and chlorides
Barbero,Degani,Diulgheroff,Dughera,Fochi
, p. 2180 - 2190 (2007/10/03)
This research comprises three parts. The first part regards the synthesis of 1-aryl-3,3-dialkyltriazenes 3 by reaction of dry arenediazonium o-benzenedisulfonimides 1, also coming from weakly basic aromatic amines with dimethylamine or diethylamine in aqueous solution at 0-5 °C. Yields were usually greater than 90% and there was the possibility of recovering the o-benzenedisulfonimide (5), which could be reused to prepare the salts 1. In the second part it was demonstrated that there is the possibility of reconverting the triazenes 3 into the starting stable dry salts 1 by using 5 as acid. The reactions were carried out in glacial acetic acid at 50-55 °C and normally afforded salts 1 in yields of around 90-99%. The third part concerns the setting up of two procedures for the conversion of 3 to aryl iodides 9, bromides 10 and chlorides 11. Procedure A used the corresponding aqueous hydrogen halides in acetonitrile at r.t. or 60 °C, sometimes in the presence of aqueous HBF4, sometimes Cu powder (25 examples, yields 65%-88%). Procedure B usually used anhydrous methanesulfonic acid and tetraalkylammonium halides in anhydrous acetonitrile at temperatures varying from r.t. to 80 °C, sometimes in the presence of Cu (16 examples, yields 65-88%).
