4922-47-8Relevant academic research and scientific papers
Safe and Metal-Free Synthesis of 1-Alkenyl Aryl Sulfides and Their Sulfones from Thiiranes and Diaryliodonium Salts
Dong, Jun,Xu, Jiaxi
supporting information, p. 2407 - 2415 (2018/04/16)
A series of 1-alkenyl aryl sulfides was synthesized from thiiranes and diaryliodonium salts in tetrahydrofuran in the presence of potassium tert -butoxide. The proposed reaction mechanism involves generation of benzynes from the diaryliodonium salts in the presence of the base. Then, nucleophilic attack of the benzynes by thiiranes, followed by hydrogen abstraction and ring opening of the generated thiiranium intermediates, provides the sulfides. These sulfides were further oxidized with performic acid to the corresponding sulfones. The current method provides a metal-free and safe method for the preparation of 1-alkenyl aryl sulfides and their sulfones.
General Synthesis of Alkenyl Sulfides by Palladium-Catalyzed Thioetherification of Alkenyl Halides and Tosylates
Velasco, Noelia,Virumbrales, Cintia,Sanz, Roberto,Suárez-Pantiga, Samuel,Fernández-Rodríguez, Manuel A.
supporting information, p. 2848 - 2852 (2018/05/29)
The cross-coupling reaction of alkenyl bromides with thiols catalyzed by palladium complexes derived from inexpensive dppf ligand is reported. These reactions occur under low catalyst loading and in high yields and display wide scope, including the coupling of bulky thiols and trisubstituted bromoolefins, and functional group tolerance. In addition, the thioetherification of less reactive chloroalkenes and, for the first time, alkenyl tosylates was accomplished using a catalyst generated from CyPFtBu alkylbisphosphine ligand.
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.
Reductive Lithiation in the Absence of Aromatic Electron Carriers. A Steric Effect Manifested on the Surface of Lithium Metal Leads to a Difference in Relative Reactivity Depending on Whether the Aromatic Electron Carrier Is Present or Absent
Kennedy, Nicole,Lu, Gang,Liu, Peng,Cohen, Theodore
, p. 8571 - 8582 (2015/09/15)
One of the most widely used methods of preparation of organolithium compounds is by the reductive lithiation of alkyl phenyl thioethers or, usually less conveniently, alkyl halides with either aromatic radical-anions of lithium or lithium metal in the presence of an aromatic electron-transfer catalyst. Here we present results showing that lithium dispersion can achieve reductive lithiation in the absence of the electron-transfer agent. This procedure is more efficient, and surprisingly, the order of reactivity of substrates is reversed depending on whether the electron-transfer agent is present or absent. For example, in the presence of a preformed radical-anion, tert-butyl phenyl sulfide cleaves significantly faster than methyl phenyl sulfide, whereas in the absence of the radical-anion, it is just the opposite. Density functional theory calculations reveal that the exothermicity of the cleavage of the C-S bond in alkyl phenyl thioethers on the lithium surface is dependent on the size of the alkyl group, the smaller the alkyl group the greater the exothermicity. The increased reactivity is attributed to the smaller steric repulsion between the alkyl group and the lithium surface. The methodology includes, but may not be limited to, the lithium dispersion reductive lithiation of phenyl thioethers, alkyl chlorides, acrolein diethyl acetal, and isochroman.
Ruthenium-catalyzed reaction of alkenyl triflates with zinc thiolates
Imazaki, Yusuke,Shirakawa, Eiji,Hayashi, Tamio
experimental part, p. 10212 - 10215 (2012/01/05)
A ruthenium complex coordinated with 3,4,7,8-tetramethyl-1,10- phenanthroline catalyzed the reaction of alkenyl triflates with zinc dithiolates to give alkenyl sulfides.
Improved and environmentally friendly large-scale preparation of cyclohexadienyl-, cycloheptadienyl sulfone and enantiopure epoxy cycloheptyl sulfones
Park, Taesik,Torres, Eduardo,Fuchs, Philip L.
, p. 1895 - 1900 (2007/10/03)
Kilogram-scale amounts of cycloheptadienyl phenylsulfone and cyclohexadienyl phenylsulfone were prepared by one operation in 5 stages with over 50% yield and requiring no purification. A practical and efficient method for the Jacobsen asymmetric epoxidati
Economical and environmentally friendly syntheses of 2-(phenylsulfonyl)-1,3-cyclohexadiene and 2-(phenylsulfonyl)-1,3-cycloheptadiene
Meyers, David J.,Fuchs, Philip L.
, p. 200 - 204 (2007/10/03)
A large-scale and inexpensive synthesis of dienes 1 and 2 has been developed via a four-step procedure starting with benzenethiol and the corresponding cyclic ketone. No chromatography is required.
Mono- and bisadducts from the addition of thianthrene cation radical salts to cycloalkenes and alkenes
Qian, Ding-Quan,Shine, Henry J.,Guzman-Jimenez, Ilse Y.,Thurston, John H.,Whitmire, Kenton H.
, p. 4030 - 4039 (2007/10/03)
Thianthrene cation radical salts, Th.+ X-(X- = a, ClO4-; b, PF6-; c, SbF6-), add to cycloalkenes (C5-C8) in acetonitrile (MeCN) to form 1,2-bis(5-thianthreniumyl)cycloalkane salts and 1,2-(5,10-thianthreniumdiyl)cycloalkane salts, most of which have now been isolated and characterized. These are called bis- (3, 6, 9, 12) and monoadducts (4, 7, 10, 13). The proportional amount of the monoadduct obtained in the initial stage of the reaction varied with the cycloalkene in the order C6 ? C5 7 ? C8. Thus, the ratio bis:mono for C5 and C7 was, respectively, about 80/20 and 50/50. In contrast, only about 5% of the C6 monoadduct (7a) and none of 7b, c was obtained, while for C8 none of the bisadducts 12a-c was found. Bisadducts 3 and 9 lost thianthrene (Th) slowly in MeCN solution and changed into monoadducts 4 and 10. A comparable change from 6a into 7a was not observed. The monoadducts, themselves, lost a proton slowly in dry MeCN and opened into 1-(5-thianthreniumyl)cycloalkenes (5, 8, 11, 14). With 3 and 9, particularly, it was possible to follow with NMR spectroscopy the succession of changes, for example, 3 to 4 to 5. The opening of a monoadduct was made faster by adding a small amount of water to the solution. The bisadducts of 4-methylcyclohexene (15a) and 1,5- cyclooctadiene (17a) were isolated and characterized. Although a small amount of monodduct (16a) of 4-methylcyclohexene was found with NMR spectroscopy, it could not be isolated. Bis- and monoadducts were obtained also in additions of Th.+ ClO4- to acyclic alkenes, in relative amounts that, again, varied with the alkene. From cis-2-butene the dominant product was the bisadduct (18), while the monoaduct (19) was characterized with NMR spectroscopy but could not be isolated. In contrast, trans-3-hexene gave mainly the monoadduct (21), while the bis adduct (20) could not be isolated. With 4-methyl-cis-2-pentene, both bis- (22) and monoadduct (23) were isolated, the former being dominant. The conversion of 18 into 19 was characterized with NMR spectroscopy. In all cycloalkene bisadducts, the configurational relationship of the two thianthrenium groups was trans, while in the monoadducts, the bonds to the single thianthrene dication were (necessarily) cis. In both bis- and monoadducts of acyclic alkenes, the configuration of the alkene was retained. The mechanisms of addition with retention of configuration, of conversion of a bis- into a monoadduct, and of opening of a monoadduct are discussed. Products were identified with a combination of NMR spectroscopy, X-ray crystallography, elemental analysis, and (for cycloalkene adducts) reaction with thiophenoxide ion.
A two-component pericyclic reaction for synthesis of substituted benzofurans and aryl-quaternary carbon bonds
Hendrickson, James B.,Walker, Martin A.
, p. 2729 - 2731 (2007/10/03)
The reaction shown is presumed to be a new [3,3]-sigmatropic rearrangement involving an O-arylsulfoxonium species or related sulfurane. It allows a sulfoxide and a phenol to be joined and rearranged in one operation at or below room temperature, coupling
Synthesis of α-methylene-β-hydroperoxy sulfoxides by regioselective photooxygenation (Schenck Reaction) of racemic vinyl sulfoxides
Adam,Kumar,Saha-Moller
, p. 1525 - 1528 (2007/10/02)
The β-hydroperoxy vinyl sulfoxides 3 were synthesized in good to excellent yields by regioselective photooxygenation of racemic vinyl sulfoxides 2. Moderate diastereoselectivities were observed in the ene reaction of singlet oxygen (Schenck Reaction) with
