7205-64-3Relevant academic research and scientific papers
Zn- And Cu-catalyzed coupling of tertiary alkyl bromides and oxalates to forge challenging C?O, C?S, and C?N bonds
Gong, Yuxin,Zhu, Zhaodong,Qian, Qun,Tong, Weiqi,Gong, Hegui
supporting information, p. 1005 - 1010 (2021/02/01)
We describe here the facile construction of sterically hindered tertiary alkyl ethers and thioethers via the Zn(OTf)2catalyzed coupling of alcohols/phenols with unactivated tertiary alkyl bromides and the Cu(OTf)2-catalyzed thiolation of unactivated tertiary alkyl oxalates with thiols. The present protocol represents one of the most effective unactivated tertiary C(sp3)? heteroatom bond-forming conditions via readily accessible Lewis acid catalysis that is surprisingly less developed.
Ni(II) Precatalysts Enable Thioetherification of (Hetero)Aryl Halides and Tosylates and Tandem C?S/C?N Couplings
Martín, M. Trinidad,Marín, Mario,Maya, Celia,Prieto, Auxiliadora,Nicasio, M. Carmen
supporting information, p. 12320 - 12326 (2021/08/09)
Ni-catalyzed C?S cross-coupling reactions have received less attention compared with other C-heteroatom couplings. Most reported examples comprise the thioetherification of most reactive aryl iodides with aromatic thiols. The use of C?O electrophiles in this context is almost uncharted. Here, we describe that preformed Ni(II) precatalysts of the type NiCl(allyl)(PMe2Ar’) (Ar’=terphenyl group) efficiently couple a wide range of (hetero)aryl halides, including challenging aryl chlorides, with a variety of aromatic and aliphatic thiols. Aryl and alkenyl tosylates are also well tolerated, demonstrating, for the first time, to be competent electrophilic partners in Ni-catalyzed C?S bond formation. The chemoselective functionalization of the C?I bond in the presence of a C?Cl bond allows for designing site-selective tandem C?S/C?N couplings. The formation of the two C-heteroatom bonds takes place in a single operation and represents a rare example of dual electrophile/nucleophile chemoselective process.
Improved, odorless access to Benzo[1,2-d;4,5-d′]-bis[1,3]dithioles and tert-butyl arylsulfides via C-S cross coupling
Fleck, Nico,Kopp, Kevin,Schiemann, Olav
, (2020/09/17)
Benzo[1,2-d;4,5-d′]bis[1,3]dithioles are important building blocks within a range of functional materials such as fluorescent dyes, conjugated polymers, and stable trityl radicals. Access to these is usually gained via tert-butyl aryl sulfides, the synthesis of which requires the use of highly malodorous tert-butyl thiol and relies on SNAr-chemistry requiring harsh reaction conditions, while giving low yields. In the present work, S-tert-butyl isothiouronium bromide is successfully applied as an odorless surrogate for tert-butyl thiol. The C-S bond formation is carried out under palladium catalysis with the thiolate formed in situ resulting in high yields of tert-butyl aryl sulfides. The subsequent formation of benzo[1,2-d;4,5-d′]bis[1,3]dithioles is here achieved with scandium(III)triflate, a less harmful reagent than the usually used Lewis acids, e.g., boron trifluoride or tetrafluoroboric acid. This enables a convenient and environmentally more compliant access to high yields of benzo[1,2-d;4,5-d′]bis[1,3]dithioles.
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.
Surfactant-Type Catalyst for Aerobic Oxidative Coupling of Hydrazine with Thiol in Water
Ren, Xuanhe,Tang, Shanyu,Li, Longjia,Li, Jiao,Liang, Helong,Li, Ganzhong,Yang, Guanyu,Li, Heng,Yuan, Bingxin
, p. 8683 - 8690 (2019/07/08)
A series of PEG-functionalized nitrogen ligands were developed to conduct an aerobic oxidative cross-coupling reaction between alkyl- or aryl-hydrazines with thiols in water. This surfactant-type catalyst enables high efficiencies and selectivities, while tolerating a large variety of functional groups. The mother liquor is still catalytically active after five runs.
Method for synthesizing asymmetric sulfide from molecular oxygen oxidation water phase under catalysis of water-soluble transition metal compound
-
Paragraph 0069-0072, (2019/07/29)
Aiming at problems that in the prior art organic solvent pollution can be caused and a great number of reaction byproducts are generated when asymmetric sulfides are prepared, the invention disclosesa method for synthesizing an asymmetric sulfide from a molecular oxygen oxidation water phase under catalysis of a water-soluble transition metal compound. The method comprises the following steps: dispersing a sulfydryl compound and a hydrazine compound as substrates in a mole ratio of 1:1 into an alkali solution, and at 40-100 DEG C, in the presence of oxygen, and with a water-soluble transitionmetal compound as a catalyst, stirring to carry out reactions, thereby obtaining the asymmetric sulfide. By adopting the method, molecular oxygen is adopted as an oxidant, and water is adopted as a solvent, so that an organic solvent is avoided, a high yield can be achieved, and the problem of byproducts can be generally avoided.
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.
Tert-Butyl Sulfoxides: Key Precursors for Palladium-Catalyzed Arylation of Sulfenate Salts
Gelat, Fabien,Lohier, Jean-Fran?ois,Gaumont, Annie-Claude,Perrio, Stéphane
supporting information, p. 2011 - 2016 (2015/06/23)
The present report describes an efficient and clean generation of sulfenate salts (R1SO-) by pyrolysis of readily available tert-butyl sulfoxides to give sulfenic acids (R1SOH) and traceless isobutene, followed by hydrogen abstraction with a weak inorganic base (K3PO4). The relevance of this process was exemplified through an in situ palladium-catalyzed cross-coupling reaction with aryl halides/triflates leading to aryl sulfoxides. The operationally simple C-S bond-forming protocol developed uses Pd(dba)2 as catalyst and Xantphos as ligand in toluene or a toluene/H2O mixture. Further extensions include the use of di-tert-butyl sulfoxide as an equivalent for sulfur monoxide dianion (SO2-) and the development of diastereoselective versions in the [2.2]paracyclophane and biaryl series.
Structural effects on the C-S bond cleavage in aryl tert -butyl sulfoxide radical cations
Cavattoni, Tullio,Del Giacco, Tiziana,Lanzalunga, Osvaldo,Mazzonna, Marco,Mencarelli, Paolo
, p. 4886 - 4894 (2013/07/11)
The oxidation of a series of aryl tert-butyl sulfoxides (4-X-C 6H4SOC(CH3)3: 1, X = OCH 3; 2, X = CH3; 3, X = H; 4, X = Br) photosensitized by 3-cyano-N-methylquinolinium perchlorate (3-CN-NMQ+) has been investigated by steady-state irradiation and nanosecond laser flash photolysis (LFP) under nitrogen in MeCN. Products deriving from the C-S bond cleavage in the radical cations 1+?-4+? have been observed in the steady-state photolysis experiments. By laser irradiation, the formation of 3-CN-NMQ? (λmax = 390 nm) and 1 +?-4+? (λmax = 500-620 nm) was observed. A first-order decay of the sulfoxide radical cations, attributable to C-S bond cleavage, was observed with fragmentation rate constants (k f) that decrease by increasing the electron donating power of the arylsulfinyl substituent from 1.8 × 106 s-1 (4 +?) to 2.3 × 105 s-1 (1 +?). DFT calculations showed that a significant fraction of the charge is delocalized in the tert-butyl group of the radical cations, thus explaining the small substituent effect on the C-S bond cleavage rate constants. Via application of the Marcus equation to the kinetic data, a very large value for the reorganization energy (λ = 62 kcal mol-1) has been calculated for the C-S bond scission reaction in 1+?-4 +?.
Nickel-mediated inter- and intramolecular C-S coupling of thiols and thioacetates with aryl iodides at room temperature
Xu, Xiao-Bo,Liu, Jian,Zhang, Jian-Jian,Wang, Ya-Wen,Peng, Yu
supporting information, p. 550 - 553 (2013/04/11)
A Ni(0)-catalyzed intermolecular cross-coupling of various functionalized thiols and aryl iodides has been developed and successfully extended to less explored intramolecular versions, where thioacetates could also be utilized as the strategic surrogate. Air-stable precatalysts, very mild conditions, and an easy protocol allow rapid access to medicinally useful aryl thioethers, as demonstrated in the facile synthesis of (±)-chuangxinmycin as a key step.
