- Site-Selective C?S Bond Formation at C?Br over C?OTf and C?Cl Enabled by an Air-Stable, Easily Recoverable, and Recyclable Palladium(I) Catalyst
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This report widens the repertoire of emerging PdI catalysis to carbon–heteroatom, that is, C?S bond formation. While Pd0-catalyzed protocols may suffer from the formation of poisonous sulfide-bound off-cycle intermediates and lack of selectivity, the mechanistically diverse PdI catalysis concept circumvents these challenges and allows for C?S bond formation (S–aryl and S–alkyl) of a wide range of aryl halides. Site-selective thiolations of C?Br sites in the presence of C?Cl and C?OTf were achieved in a general and a priori predictable fashion. Computational, spectroscopic, X-ray, and reactivity data support dinuclear PdI catalysis to be operative. Contrary to air-sensitive Pd0, the active PdI species was easily recovered in the open atmosphere and subjected to multiple rounds of recycling.
- Scattolin, Thomas,Senol, Erdem,Yin, Guoyin,Guo, Qianqian,Schoenebeck, Franziska
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supporting information
p. 12425 - 12429
(2018/09/18)
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- Microwave-assisted synthesis of substituted phenanthrenes, anthracenes, acenaphthenes, and fluorenes
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Rapid coupling reactions of polycyclic aromatic halides with various N-, S-, and Se-nucleophiles under focused microwave irradiation are described. Using this method, the desired products are obtained with good to excellent yields in a short reaction time. Crown Copyright
- Chan, Shiuh-Chuan,Jang, Jing-Pei,Cherng, Yie-Jia
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experimental part
p. 1977 - 1981
(2009/08/08)
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- Homolytic Bond Dissociation Energies of the Acidic C-H Bonds in α-Substituted and 10-Substituted 9-Methylanthracenes and Their Related Radical Anions
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Equilibrium acidities (pKHA), reduction potentials Ere(HA), oxidation potentials EOX(HA), and oxidation potentials of the conjugate anions EOX(A-) have been measured in dimethyl sulfoxide (DMSO) solution for 13 α-substituted 9-methylanthracenes (9-GCH2An) and 11 10-substituted 9-methylanthracenes (10-G-9-MeAn).The equilibrium acidities have been shown to be linearly correlated with Hammett ?- constants.The similar ρ- values for the linear correlations of pKHA vs ?- for 9-GCH2An (ρ- = 13.8) and 10-G-9-MeAn (ρ- = 14.2) demonstrate that the like substituents in 9-GCH2An and 10-G-9-MeAn have similar large effects on the equilibrium acidities.Suitable combinations of these equilibrium acidities with the reduction and oxidation potentials led to estimates of (a) the homolytic bond dissociation energies (BDEHA) of the acidic C-H bonds in 9-GCH2An and 10-G-9-MeAn, (b) the homolytic bond dissociation energies (BDEHA*-%) of the acidic C-H bonds in 9-GCH2An*- and 10-G-9-MeAn*- radical anions, and (c) the radical cation acidities (pKHA*+%) of the 9-GCH2An*+ and 10-G-9-MeAn*+ radical cations.Introduction of α-CN and α-NO2 groups had opposite effects on the strengths (BDEHA) of the acidic C-H bonds in 9-GCH2An; the α-CN group decreased the BDEHA value by 2.5 kcal/mol and the α-NO2 increased the BDEHA value by 4.5 kcal/mol, but they both weakened the acidic C-H bonds in 9-GCH2An*- radical anions (by 10.6 and 12.5 kcal/mol, respectively).The BDEs of the acidic C-H bonds in 10-G-9-MeAn were estimated to be 81.3 +/- 1.3 kcal/mol and those in the corresponding radical anions were estimated to be 58.5 +/- 2.5 kcal/mol.The 9-GCH2An*+ and 10-G-9-MeAn*+ radical cations are strongly acidic with the pKHA*+% values estimated in the range of -5 to -11 pKHA*+% units.Seven linear free energy relationships have been observed.
- Zhang, Xian-Man,Bordwell, Frederick G.,Bares, Joseph E.,Cheng, Jin-Pei,Petrie, Brian C.
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p. 3051 - 3059
(2007/10/02)
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- The Reaction of 9-Bromoanthracene with Benzenethiolate Anion in Tetraglyme: Evidence against a Competing Electron-Transfer Mechanism
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The reaction of 9-bromoanthracene (1) with benzenethiol(ate) in tetraglyme proceeds by a SNAr mechanism.The concurrent formation of anthracene is not due to a competing single-electron-transfer pathway involving either benzenethiol or benzenethiolate anion.
- Baumgarner, Charles D.,Malen, Alyssa H.,Pastor, Stephen D.,NabiRahni, M. Ali
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p. 480 - 486
(2007/10/02)
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- Sur le comportement cathodique inattendu des di-aryl sulfoxydes en solvant de tres faible acidite
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When conducted in aprotic solvents the cathodic reduction of aromatic sulphoxides (only able to lead to an electron transfer under such conditions) does not afford the quantitative formation of the corresponding sulphides.On the contrary, one observes the conversion into a mixture sulphide/sulphone in a molar ratio 1/1 followed in most of the cases by the cathodic cleavage of the sulphone.Reasons for such a are analysed.
- Djeghidjegh, Nouredine,Simonet, Jacques
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- Reactions of Haloarenes with Thiolate Anions in Tetraglyme: Cmpetition between Electron Transfer and SNAr Mechanisms
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The reaction of the bromo-substituted naphthalene 1 with the alkanethiolate anions 2a-b and arenethiolate 2c in tetraglyme gave the corresponding 1-naphthyl thio-ethers 3a-c.Thio-ethers 3a-c were oxidized to the corresponding sulfones 4a-c with m-chloroperoxybenzoic acid.The reaction of the dichloro-substituted anthracene 5a with 2b gave the disubstitution product 6a.The reaction of 9-bromoanthracene 5c with the alkanethiolate 2b gave 6b, whereas the reaction of 5c with the arenethiolate 2c gave a mixture of aubstitution product 6c and anthracene 7.The observation of the formation of both 6c and 7 is explained by the competition between substitution (SNAr) and electron-transfer (ET) mechanisms.Consistent with this interpretation, the reaction of the monochloro-substituted 5b, which has a higher-energy ?* orbital, with 2c gave 6c without the formation of 7.Zn/KOH in tetraglyme was shown to reduce the aryl halides 5b-c and thio-ether 6c to 7.
- Pastor, Stephen D.
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p. 859 - 866
(2007/10/02)
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- HIGH-TEMPERATURE ORGANIC SYNTHESIS. XXVIII. LIQUID-PHASE REACTIONS OF THIOLS WITH AROMATIC BROMINE COMPOUNDS
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In the liquid phase at 125-215 deg C thiophenol only reacts effectively with 2- and 4-bromophenol, 1-bromo-2-napthol, 1-bromonapthalene, and 9-bromoanthracene, forming the corresponding phenyl aryl sulfides. 2-Thiophenethiol and 1-thionapthol reduce the same bromine derivatives to the corresponding arenes.The disulfides formed here undergo secondary transformations.The reactions of thiophenol with 2- and 4-bromophenol and 1-bromo-2-napthol are convenient preparative methods for the synthesis of the previously difficulty obtainable phenyl hydroxyaryl sulfides.
- Papernaya, L. K.,Panova, G. M.,Deryagina, E. N.,Voronkov, M. G.
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p. 1774 - 1777
(2007/10/02)
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- REACTION OF BENZYNES WITH 9-t-BUTYLTHIOANTHRACENE TO AFFORD 9-t-BUTYLTHIOTRIPTYCENES
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Reaction of benzynes (3a,c,d) with 9-t-butylthioanthracene (2d) resulted in formation of the corresponding 9-t-butylthiotriptycenes (5a,c,d) and 5-t-butylthio-6,11-dihydro-6,11-ethenonaphthacenes (6a,c,d), while that of 1,4-dimethoxybenzyne (3b) with 2d did not give the corresponding adducts (5b,6b).
- Nakamura, Nobuo
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p. 1795 - 1798
(2007/10/02)
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- REACTIONS OF 9-NITROANTHRACENE WITH THIOLS IN LIQUID AMMONIA
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Anthrylsulfides were obtained in high yields in the reaction of 9-nitroanthracene 1 with thiols.The reactions with thiolates resulted in the formation of aci-9,9'-dinitro-10,10'-dihydro-10,10'-bianthryl 2 via a 9-nitroanrthracene anion radical.
- Takikawa, Yuji,Abe, Toshihiko,Sato, Ryu,Takizawa, Saburo
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