2845-89-8Relevant articles and documents
A Convenient and Stable Heterogeneous Nickel Catalyst for Hydrodehalogenation of Aryl Halides Using Molecular Hydrogen
Anwar, Muhammad,Beller, Matthias,Dastgir, Sarim,Junge, Kathrin,Leonard, David K.,Ryabchuk, Pavel
, (2022/02/03)
Hydrodehalogenation is an effective strategy for transforming persistent and potentially toxic organohalides into their more benign congeners. Common methods utilize Pd/C or Raney-nickel as catalysts, which are either expensive or have safety concerns. In this study, a nickel-based catalyst supported on titania (Ni-phen@TiO2-800) is used as a safe alternative to pyrophoric Raney-nickel. The catalyst is prepared in a straightforward fashion by deposition of nickel(II)/1,10-phenanthroline on titania, followed by pyrolysis. The catalytic material, which was characterized by SEM, TEM, XRD, and XPS, consists of nickel nanoparticles covered with N-doped carbon layers. By using design of experiments (DoE), this nanostructured catalyst is found to be proficient for the facile and selective hydrodehalogenation of a diverse range of substrates bearing C?I, C?Br, or C?Cl bonds (>30 examples). The practicality of this catalyst system is demonstrated by the dehalogenation of environmentally hazardous and polyhalogenated substrates atrazine, tetrabromobisphenol A, tetrachlorobenzene, and a polybrominated diphenyl ether (PBDE).
Ni-Catalyzed Reductive Cyanation of Aryl Halides and Phenol Derivatives via Transnitrilation
Mills, L. Reginald,Graham, Joshua M.,Patel, Purvish,Rousseaux, Sophie A. L.
supporting information, p. 19257 - 19262 (2019/12/02)
Herein, we report a Ni-catalyzed reductive coupling for the synthesis of benzonitriles from aryl (pseudo)halides and an electrophilic cyanating reagent, 2-methyl-2-phenyl malononitrile (MPMN). MPMN is a bench-stable, carbon-bound electrophilic CN reagent that does not release cyanide under the reaction conditions. A variety of medicinally relevant benzonitriles can be made in good yields. Addition of NaBr to the reaction mixture allows for the use of more challenging aryl electrophiles such as aryl chlorides, tosylates, and triflates. Mechanistic investigations suggest that NaBr plays a role in facilitating oxidative addition with these substrates.
Search for a photoinduced (site-selective) cleavage of the Ar-Cl bond in dichloroanisoles
Raviola, Carlotta,Fagnoni, Maurizio
, p. 107 - 117 (2018/02/06)
The site-selective cleavage of an Ar-X bond in polyhalogenated aromatics is an important tool in synthetic planning especially when more than one identical halogen atom is present. An alternative to the usual metal-catalyzed cleavage is represented by photochemistry although only a few examples have been reported. We then investigated the feasibility of the site-selective photodechlorination of some dichloroanisoles through a combined experimental and computational study. In the case of 2,4-dichloroanisole, selective detachment of the chlorine atom at the ortho position with respect to the OMe group was observed upon photohomolysis (in cyclohexane) or photoheterolysis (in MeOH) of the Ar-Cl bond. In the latter case, 5-chloro-2-methoxy-1,1′-biphenyl was exclusively formed upon reaction of the resulting phenyl cation with benzene. The substitution of an OH group for a OMe group was detrimental since a lower photoreactivity resulted with no improvement in the selectivity.
A highly efficient heterogeneous copper-catalyzed chlorodeboronation of arylboronic acids leading to chlorinated arenes
He, Wen,Zhang, Rongli,Cai, Mingzhong
, p. 764 - 770 (2017/01/13)
A highly efficient heterogeneous copper-catalyzed chlorodeboronation of arylboronic acids with inexpensive N-chlorosuccinimide (NCS) was achieved in MeCN in the presence of 10 mol% of l-proline-functionalized MCM-41-immobilized copper(i) complex [MCM-41-l-proline-CuCl] under mild conditions, yielding a variety of aryl chlorides in excellent yields. This method proved to be tolerant of a broad range of functional groups and particularly useful for the conversion of electron-deficient arylboronic acids to aryl chlorides, a transformation that is inefficient without copper catalysis. This heterogeneous copper catalyst can be recovered by a simple filtration of the reaction solution and recycled for at least 10 times without any decreases in activity.
Functionalised [(NHC)Pd(allyl)Cl] complexes: Synthesis, immobilisation and application in cross-coupling and dehalogenation reactions
Collinson, John-Michael,Wilton-Ely, James D.E.T.,Díez-González, Silvia
, p. 78 - 81 (2016/09/23)
A novel NHC–palladium(II) (NHC?=?N-heterocyclic carbene) complex and its immobilised version have been prepared and fully characterised. Optimisation studies led to good catalytic activities in Suzuki-Miyaura cross coupling and chloroarene dehalogenation reactions. Furthermore, the unexpected palladium-mediated transfer hydrogenation of a carbonyl compound is reported.
Radiolabeling of aromatic compounds using K[*Cl]Cl and OXONE
Takada, Yuuki,Hanyu, Masayuki,Nagatsu, Kotaro,Fukumura, Toshimitsu
, p. 383 - 386,4 (2020/08/24)
We report a novel labeling method for the rapid radiochlorination of aromatic compounds using no-carrier-added short-half-life radioactive chloride ions ([38,39Cl]Cl- and [34mCl]Cl-) and OXONE (Sigma-Aldrich, Japan) as an oxidation reagent. The reaction of radioactive chloride ions with anisole in the presence of OXONE gave a mixture of p-[*Cl]chloroanisole and o-[*Cl]-chloroanisole, with a radiochemical conversion yield of more than 85% (not decay corrected) and selectivity of 7:3, within 10 min. Regioselective radioactive chlorination was achieved by chlorodestannylation of tributylstannyl compounds to afford the corresponding radiochlorinated compounds (p-chloroanisole and m-chloroanisole) in satisfactory radiochemical yields (80-95% and 46-65%, respectively). Copyright
Novel analogues of ketamine and phencyclidine as NMDA receptor antagonists
Zarantonello, Paola,Bettini, Ezio,Paio, Alfredo,Simoncelli, Chiara,Terreni, Silvia,Cardullo, Francesco
scheme or table, p. 2059 - 2063 (2011/04/24)
The identification of structurally novel analogues of ketamine and phencyclidine (PCP), as NMDA receptor antagonists, with low to moderate potency at GluN2A and GluN2B receptors is discussed. In particular, some examples, such as compounds 6 and 10, shows decreased calculated lipophilicity, when compared to PCP, while retaining moderate activity. Moreover, the germinal aryl amino substituted lactam ring, as exemplified in compounds 7-10 and 11-13, constitutes a novel scaffold with potential application in the design of biologically active compounds.
Gold-catalysis: Reactions of organogold compounds with electrophiles
Hashmi, A. Stephen K.,Ramamurthi, Tanuja Dondeti,Todd, Matthew H.,Tsang, Althea S.-K.,Graf, Katharina
experimental part, p. 1619 - 1626 (2011/09/12)
Different arylgold(I), one alkynylgold(I), and one vinylgold(I) triphenylphosphane complexes were subjected to electrophilic halogenation reagents. With N-chlorosuccinimid, N-bromosuccinimid, and N-iodosuccinimid as well as the Barluenga reagent, selectively halogenated compounds were obtained. Trifluoroacetic acid, as a source of protons, leads to a clean protodeauration. With N-fluorobenzenesulfonimide or Selectfluor, exclusively a homocoupling was observed. For the precursor of the vinylgold(I) complex, a similar oxidative coupling could be induced by gold(III) chloride. Reactions with silicon or tin electrophiles failed. CSIRO 2010.
Catalytic Friedel-Crafts acylation of aromatic ethers using Sml3
Chen, Xiaohang,Yu, Mingxin,Wang, Meijun
, p. 80 - 81 (2007/10/03)
10% mol Sml3 catalysed the Friedel-Crafts acylation of aromatic ethers by acyl chlorides in acetonitrile with the yields of 48-82%. Reactions of various substituted aromatic ethers with acyl chloride were studied. The structures of compounds were established by IR and 1H NMR. The main product obtained with anisole is the para-substituted compound with only a trace (3, a pattern repeated with the other aromatic ethers used.
The tertiary sulfonamide as a latent directed-metalation group: Ni 0-catalyzed reductive cleavage and cross-coupling reactions of aryl sulfonamides with Grignard reagents
Milburn, Robert R.,Snieckus, Victor
, p. 888 - 891 (2007/10/03)
A mild method for the Ni0-catalyzed hydrodesulfamoylation (see scheme, B) of aryl sulfonamides (1→2) with iPr2Mg or iPrMgCl as β-hydride transfer sources can be linked with directed ortho metalation (A and C) to give meta-substituted aromatics 2. Cross-coupling process with alkyl and aryl Grignard reagents furnish disubstituted benzenes and bi- and teraryl compounds.
