13524-73-7Relevant articles and documents
The preparation and use of polyHIPE-grafted reactants to reduce alkyl halides under free-radical conditions
Chemin, Alexandre,Mercier, Anthony,Deleuze, Herve,Maillard, Bernard,Mondain-Monval, Olivier
, p. 366 - 370 (2001)
PolyHIPE-supported tin hydride and thiol are synthesized to reduce alkyl bromides under free-radical conditions, taking advantage of the fully interconnected polyHIPE structure. Radical reduction of 1-bromoadamantane, 6-bromohex-1-ene and 1-allyloxy-2-bromobenzene are performed using two methodologies: one using supported tin hydride as reducing agent, and another using supported thiol as polarity-reversal catalyst in the presence of triethylsilane as reducing agent. The polyHIPE-supported tin hydride is used either in catalytic or stoichiometric amounts depending on the bromo compound to be reduced. In the case of unsaturated bromides, both methodologies lead to reductive cyclization, thus enabling radical rearrangement before hydrogen transfer. PolyHIPE-supported organotin hydride is a good alternative to tributyltin hydride to prevent tin contamination and facilitate product separation. PolyHIPE-supported thiol, in the presence of an excess of triethylsilane, shows good activity and selectivity toward reductive cyclization products. Results obtained by the two methodologies are compared and discussed.
Intermediacy of Aryl Radicals and Arylmetal Compounds in Reductive Dehalogenation of Halogenoarenes with Lithium Aluminium Hydride
Beckwith, Athelstan L. J.,Goh, Swee Hock
, p. 905 - 906 (1983)
Reduction of o-allyloxybromobenzene (1) with lithium aluminium hydride proceeds by two competing pathways; one involving aryl radicals is promoted by oxygen, the other affords initially an arylmetal compound.
Radical cyclisation of 1-bromo-2-(prop-2-enyloxy)benzene using a polymer-supported organotin hydride
Lapotre,Deleuze,Maillard,Mulholland
, p. 3207 - 3218 (2001)
The use of polymer-supported organotin hydride for the cyclisation 1-bromo-2-(prop-2-enyloxy)benzene I to give 2,3-dihydro-3-methylbenzofuran II has been studied. The supports were prepared by suspension copolymerisation of an organotin-functionalised monomer. Two approaches have been investigated either using a stoichiometric or a catalytic amount of organotin support.
Photo-induced thiolate catalytic activation of inert Caryl-hetero bonds for radical borylation
K?nig, Burkhard,Wang, Hua,Wang, Shun
supporting information, p. 1653 - 1665 (2021/06/17)
Substantial effort is currently being devoted to obtaining photoredox catalysts with high redox power. Yet, it remains challenging to apply the currently established methods to the activation of bonds with high bond dissociation energy and to substrates with high reduction potentials. Herein, we introduce a novel photocatalytic strategy for the activation of inert substituted arenes for aryl borylation by using thiolate as a catalyst. This catalytic system exhibits strong reducing ability and engages non-activated Caryl–F, Caryl–X, Caryl–O, Caryl–N, and Caryl–S bonds in productive radical borylation reactions, thus expanding the available aryl radical precursor scope. Despite its high reducing power, the method has a broad substrate scope and good functional-group tolerance. Spectroscopic investigations and control experiments suggest the formation of a charge-transfer complex as the key step to activate the substrates.
Radical Hydrodehalogenation of Aryl Bromides and Chlorides with Sodium Hydride and 1,4-Dioxane
Hokamp, Tobias,Dewanji, Abhishek,Lübbesmeyer, Maximilian,Mück-Lichtenfeld, Christian,Würthwein, Ernst-Ulrich,Studer, Armido
supporting information, p. 13275 - 13278 (2017/10/09)
A practical method for radical chain reduction of various aryl bromides and chlorides is introduced. The thermal process uses NaH and 1,4-dioxane as reagents and 1,10-phenanthroline as an initiator. Hydrodehalogenation can be combined with typical cyclization reactions, proving the nature of the radical mechanism. These chain reactions proceed by electron catalysis. DFT calculations and mechanistic studies support the suggested mechanism.
Copper-Mediated Trifluoroacetylation of Arenediazonium Salts with Ethyl Trifluoropyruvate
Wu, Wei,Tian, Qinli,Chen, Taotao,Weng, Zhiqiang
supporting information, p. 16455 - 16458 (2016/11/11)
A copper-mediated trifluoroacetylation of various arenediazonium salts with ethyl trifluoropyruvate is reported. The reaction proceeded smoothly under mild conditions at room temperature giving trifluoromethyl aryl ketones in moderate to good yields. A variety of functional groups, including methoxy, hydroxy, ester, ketone, trifluoromethyl, and halide groups, were well tolerated. A possible reaction mechanism involving an aryl radical intermediate was proposed and supported by experimental evidence. This reaction provides a new route to trifluoromethyl aryl ketones, notable synthetic targets, from the corresponding anilines.
