2974-06-3Relevant academic research and scientific papers
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.
Aryl thioether compound and preparation method thereof
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Paragraph 0015, (2021/11/27)
The invention discloses an aryl thioether compound and a synthesis method thereof, wherein an aryl carboxylic acid and a mercaptan (phenol) are used as main raw materials, and a nickel catalyst is prepared. Under the action of the phosphine ligand and the additive, the aryl carboxylic acid and the thiol (phenol) react in an organic solvent, and after the reaction is finished, the corresponding aryl thioether is obtained. The method has the advantages of low cost, high yield, simple and convenient operation, no pollution and the like, and has potential industrial application prospects. The method provides a cheap and green way for preparation of aryl thioether compounds.
Chan-Lam-Type C-S Coupling Reaction by Sodium Aryl Sulfinates and Organoboron Compounds
Lam, Long Yin,Ma, Cong
supporting information, p. 6164 - 6168 (2021/08/16)
A Chan-Lam-Type C-S coupling reaction using sodium aryl sulfinates has been developed to provide diaryl thioethers in up to 92% yields in the presence of a copper catalyst and potassium sulfite. Both electron-rich and electron-poor sodium aryl sulfinates and diverse organoboron compounds were tolerated for the synthesis of aryl and heteroaryl thioethers and dithioethers. The mechanistic study suggested that potassium sulfite was involved in the deoxygenation of sulfinate through a radical process.
Preventing Pd-NHC bond cleavage and switching from nano-scale to molecular catalytic systems: Amines and temperature as catalyst activators
Ananikov, Valentine P.,Astakhov, Alexander V.,Chernenko, Andrey Yu.,Chernyshev, Victor M.,Khazipov, Oleg V.,Pasyukov, Dmitry V.,Shevchenko, Maxim A.,Tafeenko, Victor A.
, p. 1228 - 1247 (2020/03/26)
Many reactions catalyzed by Pd complexes with N-heterocyclic carbene (NHC) ligands are performed in the presence of amines which usually act as coupling reagents or mild bases. However, amines can react with Pd/NHC complexes in a number of ways: enhancing molecular catalysis, causing the catalyst deactivation or triggering the ligandless modes of catalysis by producing NHC-free active palladium species. This study gains insight into conditions required for the efficient use of amines as activators of molecular Pd/NHC catalysis and preventing the undesirable reductive cleavage of the Pd-NHC bond in catalytic systems. Reactions of Pd/NHC complexes with various amines within a temperature range of 25-140 °C and thermal stability of the resulting amino-complexes are examined. The results indicate the major influence of the amine structure and reaction temperature on the catalyst transformation. In particular, thermal decomposition of Pd/NHC complexes with aliphatic amine ligands predominantly leads to reductive Pd-NHC bond cleavage, while deprotonation of the complexes with primary and secondary aliphatic amine ligands in the presence of strong bases at 25-60 °C promotes the activation of molecular Pd/NHC catalysis. Efficient Pd-PEPPSI complex-amine systems suitable for strong-base-promoted C-S cross-coupling reactions between aryl halides and thiols are suggested on the basis of these findings.
AlCl3-mediated aromatic phenylthiation with N-phenylthiophthalimide
Suwa, Satoshi,Sakamoto, Takeshi,Kikugawa, Yasuo
, p. 980 - 982 (2007/10/03)
N-Phenylthiophthalimide reacts with AlCl3 or TiCl4 in arenes to give phenylthiated arenes alone via a phenylsulfenium ion intermediate, modified neglect of diatomic overlap (MNDO) molecular orbital calculations of which revealed that the positive charge preferentially populates the sulfur atom rather than the phenyl group in the phenylsulfenium ion.
INNOVATIVE APPROACH TO THE SYNTHESIS OF SULPHIDES AND THEIR CORRESPONDING SULPHONES
Abd-El-Aziz, Alaa S.,Epp, Karen M.,Lei, Yun,Kotowich, Steven
, p. 1252 - 1286 (2007/10/02)
A general and efficient synthetic approach to aryl-aryl bis-sulphides with aliphatic or aromatic bridges via the nucleophilic aromatic substitution (SNAr) of cyclopentadienyliron arene complexes with a number of dithiols followed by photolytic demetallation is presented in this work.The oxidation of the bis(cyclopentadienyliron) arene complexes containing bis-sulphide linkages with 3-chlorobenzoic acid gave their corresponding sulphones in very good yield (70-95percent).Mixed ether/sulphide and ether/sulphone complexes were also prepared following the same synthetic strategy.Reactions of sulphide and sulphone diiron complexes with terminal chloro groups with a number of oxygen, sulphur and carbon nucleophiles allowed for the functionalization of these complexes.The use of photolytic demetallation as a means of liberating the modified arene ligands proved to be very successful.The mild conditions, high yields and low cost of the starting iron complexes make this method one of the most general and practical routes to sulphide and sulphone compounds.
