3019-19-0Relevant articles and documents
A Robust Pd-Catalyzed C-S Cross-Coupling Process Enabled by Ball-Milling
Browne, Duncan L.,Jones, Andrew C.,Nicholson, William I.,Smallman, Harry R.
supporting information, p. 7433 - 7438 (2020/10/09)
An operationally simple mechanochemical C-S coupling of aryl halides with thiols has been developed. The reaction process operates under benchtop conditions without the requirement for a (dry) solvent, an inert atmosphere, or catalyst preactivation. The reaction is finished within 3 h. The reaction is demonstrated across a broad range of substrates; the inclusion of zinc metal has been found to be critical in some instances, especially for coupling of alkyl thiols.
C[sbnd]S cross-coupling catalyzed by a series of easily accessible, well defined Ni(II) complexes of the type [(NHC)Ni(Cp)(Br)]
Rodríguez-Cruz, Mario A.,Hernández-Ortega, Simón,Valdés, Hugo,Rufino-Felipe, Ernesto,Morales-Morales, David
, p. 193 - 198 (2020/02/13)
The synthesis, characterization and catalytic evaluation of a series of NHC-Ni(II) complexes 1-Ni (-Me), 2-Ni (-nBu) and 3-Ni (-Bn) bearing a phthalimide fragment and a cyclopentadienyl (Cp) ligand is reported. The complexes were evaluated in C
Deprotonated Salicylaldehyde as Visible Light Photocatalyst
Zhuang, Yan-Jun,Qu, Jian-Ping,Kang, Yan-Biao
, p. 4386 - 4397 (2020/03/05)
Salicylaldehyde is established as an efficient visible light photocatalyst for the first time. Compared to other simple aldehyde analogies, salicylaldehyde has a unique deprotonative red-shift from 324 to 417 nm and gives rise to the remarkable increase of fluorescence quantum from 0.0368 to 0.4632, thus enabling salicylaldehyde as a visible light (>400 nm) photocatalyst. The experimental investigations suggest that the reactive radical species are generated by sensitization of the substrates by the deprotonated salicylaldehyde through an energy-transfer pathway. Consequently, the C-C cleaving alkylation reactions of N-hydroxyphthalimide esters proceed smoothly in the presence of as low as 1 mol % of salicylaldehyde under the visible-light irradiation, affording desired alkylation products with up to 99% yields. Application in visible-light induced aerobic oxidation of N-alkylpyridinium salts is also reported.
Iodosylbenzene Coordination Chemistry Relevant to Metal-Organic Framework Catalysis
Cardenal, Ashley D.,Maity, Asim,Gao, Wen-Yang,Ashirov, Rahym,Hyun, Sung-Min,Powers, David C.
supporting information, p. 10543 - 10553 (2019/09/13)
Hypervalent iodine compounds formally feature expanded valence shells at iodine. These reagents are broadly used in synthetic chemistry due to the ability to participate in well-defined oxidation-reduction processes and because the ligand-exchange chemist
Transalkylation of alkyl aryl sulfides with alkylating agents
Nawrot, Daria,Koleni?, Marek,Kune?, Ji?í,Kostelansky, Filip,Miletin, Miroslav,Novakova, Veronika,Zimcik, Petr
, p. 594 - 599 (2018/01/01)
The reaction of methyl iodide with tert-butylphenylsulfide in DMF leads to a transalkylation that produces methylphenylsulfide. This transalkylation reaction was further studied by 1H NMR spectroscopy. The polarity of the solvent, the electron density on the sulfur atom, and the strength of the alkylating agent (MeI, EtI, BuI, dimethyl sulfate, or dimethyl carbonate) played important roles in the reaction. The suggested mechanism of the reaction involves the formation of a dialkyl aryl sulfonium salt that subsequently eliminates the radical. This mechanism was supported by the observation of higher conversion rates for compounds with more branched alkyl groups on the sulfur atom, which may lead to the formation of more stable radicals.
Oxidation of Organosulfides to Organosulfones with Trifluoromethyl 3-Oxo-1λ 3,2-benziodoxole-1(3 H)-carboxylate as an Oxidant
Mangaonkar, Saeesh R.,Kole, Priyanka B.,Singh, Fateh V.
supporting information, p. 199 - 202 (2017/09/28)
An alternative approach is described for the oxidation of organosulfides to the corresponding organosulfones by using trifluoromethyl 3-oxo-1λ 3,2-benziodoxole-1(3 H)-carboxylate as an oxidant. The oxidation of the sulfides was performed by using 2.4 equivalents of the oxidant in refluxing acetonitrile. The oxidation products were isolated in good to excellent yields.
SPS–Ni(II) pincer compounds of the type [Ni(phPS2)(P(C6H4-4-R)3)] Synthesis, characterization and catalytic evaluation in C–S cross-coupling reactions
Gómez-Benítez, Valente,Valdés, Hugo,Hernández-Ortega, Simón,Germán-Acacio, Juan Manuel,Morales-Morales, David
, p. 144 - 148 (2017/10/13)
The synthesis and characterization of a series of SPS–Ni(II) pincer complexes with different para-substituted triphenylphosphines has been performed. The molecular structure of [Ni(phPS2)(PPh3)] (1) (phPS2H2 = PhP(C6H4-2-SH)2, bis(phenyl-2-thiol)phenylphosphine) was unequivocally determined by single crystal X-ray diffraction analysis. The metal centre exhibited a slightly distorted square planar geometry. The complexes showed a high catalytic activity in the C–S cross-coupling reaction of both alkyl- and aryl-disulfides with iodobenzenes for the production of non-symmetric sulfides. In general, the different para-substituted triphenylphosphine ligands do not affect the catalytic performance of the SPS–Ni(II) complexes. However, activity of the catalyst decreases with the steric hindrance of the different alkyl groups in the disulphide substrates.
Nickel Phosphite/Phosphine-Catalyzed C-S Cross-Coupling of Aryl Chlorides and Thiols
Jones, Kieran D.,Power, Dennis J.,Bierer, Donald,Gericke, Kersten M.,Stewart, Scott G.
supporting information, p. 208 - 211 (2018/01/17)
A method for the coupling of aryl chlorides and thiophenols using an air-stable nickel(0) catalyst is described. This thioetherification procedure can be effectively applied to a range of electronically diverse aryl/heteroaryl chlorides without more expensive metal catalysts such as palladium, iridium, or ruthenium. This investigation also illustrates both, a variety of thiol coupling partners and, in certain cases, the use of Cs2CO3.
Fundamental Difference in Reductive Lithiations with Preformed Radical Anions versus Catalytic Aromatic Electron-Transfer Agents: N,N-Dimethylaniline as an Advantageous Catalyst
Kennedy, Nicole,Liu, Peng,Cohen, Theodore
supporting information, p. 383 - 386 (2016/01/25)
The reductive lithiation of phenyl thioethers, or alkyl chlorides, by either preformed aromatic radical anions or by lithium metal and an aromatic electron-transfer catalyst, is commonly used to prepare organolithiums. Revealed herein is that these two methods are fundamentally different. Reductions with radical anions occur in solution, whereas the catalytic reaction occurs on the surface of lithium, which is constantly reactivated by the catalyst, an unconventional catalyst function. The order of relative reactivity is reversed in the two methods as the dominating factor switches from electronic to steric effects of the alkyl substituent. A catalytic amount of N,N-dimethylaniline (DMA) and Li ribbon can achieve reductive lithiation. DMA is significantly cheaper than alternative catalysts, and conveniently, the Li ribbon does not require the removal of the oxide coating when DMA is used as the catalyst.
