42917-47-5Relevant academic research and scientific papers
Paired Electrolysis Enabled Ni-Catalyzed Unconventional Cascade Reductive Thiolation Using Sulfinates
Kang, Jun-Chen,Li, Zi-Hao,Chen, Chao,Dong, Li-Kun,Zhang, Shu-Yu
supporting information, p. 15326 - 15334 (2021/10/25)
Herein, we have reported a nickel-catalyzed cascade reductive thiolation of aryl halides with sulfinates driven by paired electrolysis. This protocol uses sulfinates as the sulfur source, and various thioethers could be synthesized under mild conditions. By mechanism exploration, we find that a cascade chemical step is allowed on the electrode interface and could alter the reaction pathway in paired electrolysis, whose findings could help the discovery of novel cascade reactions with unique reactivity.
Coupling of thiols and aromatic halides promoted by diboron derived super electron donors
Franco, Mario,Vargas, Emily L.,Tortosa, Mariola,Cid
supporting information, p. 11653 - 11656 (2021/11/12)
We have proven that pyridine-boryl complexes can be used as superelectron donors to promote the coupling of thiols and aromatic halides through a SRN1 mechanism. The reaction is efficient for a broad substrate scope, tolerating heterocycles including pyridines, enolizable or reducible functional groups. The method has been applied to intermediates in drug synthesis as well as interesting functionalized polythioethers through a controlled and consecutive intramolecular electron transfer process.
Photoredox Nickel-Catalyzed C-S Cross-Coupling: Mechanism, Kinetics, and Generalization
Qin, Yangzhong,Sun, Rui,Gianoulis, Nikolas P.,Nocera, Daniel G.
supporting information, p. 2005 - 2015 (2021/02/06)
Photoredox-mediated nickel-catalyzed cross-couplings have evolved as a new effective strategy to forge carbon-heteroatom bonds that are difficult to access with traditional methods. Experimental mechanistic studies are challenging because these reactions involve multiple highly reactive intermediates and perplexing reaction pathways, engendering competing, but unverified, proposals for substrate conversions. Here, we report a comprehensive mechanistic study of photoredox nickel-catalyzed C-S cross-coupling based on time-resolved transient absorption spectroscopy, Stern-Volmer quenching, and quantum yield measurements. We have (i) discovered a self-sustained productive Ni(I/III) cycle leading to a quantum yield φ > 1; (ii) found that pyridinium iodide, formed in situ, serves as the dominant quencher for the excited state photocatalyst and a critical redox mediator to facilitate the formation of the active Ni(I) catalyst; and (iii) observed critical intermediates and determined the rate constants associated with their reactivity. Not only do the findings reveal a complete reaction cycle for C-S cross-coupling, but the mechanistic insights have also allowed for the reaction efficiency to be optimized and the substrate scope to be expanded from aryl iodides to include aryl bromides, thus broadening the applicability of photoredox C-S cross-coupling chemistry.
Nickel-Catalyzed Decarbonylative Thioetherification of Acyl Fluorides via C-F Bond Activation
You, Jingwen,Chen, Qiang,Nishihara, Yasushi
supporting information, p. 3045 - 3050 (2021/05/31)
Nickel-catalyzed decarbonylative thioetherification of acyl fluorides has been developed. This transformation allows an array of acyl fluorides to react with thiophenols. A wide range of functional groups are well tolerated and the corresponding sulfides can be obtained in good to excellent yields. This protocol provides the formation of diverse carbon-sulfur bonds via a highly efficient decarbonylative process.
Concerted aryl-sulfur reductive elimination from PNP pincer-supported Co(iii) and subsequent Co(i)/Co(iii) comproportionation
Foley, Bryan J.,Palit, Chandra Mouli,Bhuvanesh, Nattamai,Zhou, Jia,Ozerov, Oleg V.
, p. 6075 - 6084 (2020/07/10)
This report discloses a combined experimental and computational study aimed at understanding C-S reductive elimination from Co(iii) supported by a diarylamido/bis(phosphine) PNP pincer ligand. Divalent (PNP)Co-aryl complexes could be easily oxidized to five-coordinate Co(iii) derivatives, and anion metathesis provided five-coordinate (PNP)Co(Ar)(SAr′) complexes of Co(iii). In contrast to their previously described (POCOP)Co(Ar)(SAr′) analogs, but similarly to the (PNP)Rh(Ar)(SAr′) and (POCOP)Rh(Ar)(SAr′) analogs, (PNP)Co(Ar)(SAr′) undergo C-S reductive elimination with the formation of the desired diarylsulfide product ArSAr′. DFT studies and experimental observations are consistent with a concerted process. However, in contrast to the Rh analogs, the immediate product of such reductive elimination, the unobserved Co(i) complex (PNP)Co, un-dergoes rapid comproportionation with the (PNP)Co(Ar)(SAr′) starting material to give Co(ii) compounds (PNP)Co-Ar and (PNP)Co-SAr′.
DABCO-promoted Diaryl Thioether Formation by Metal-catalyzed Coupling of Sodium Sulfinates and Aryl Iodides
Liu, Yanpeng,Lam, Long Yin,Ye, Jiqing,Blanchard, Nicolas,Ma, Cong
supporting information, p. 2326 - 2331 (2020/05/05)
A scalable catalytic synthesis method using commodity chemicals for constructing diaryl thioethers directly from sodium arylsulfinates and iodoarenes is reported in this study. In the presence of CuO or other copper salts such as Cu(OAc)2 as well as palladium catalysts, DABCO demonstrated to be essential to promote this transformation. Various iodoarenes and aryl sulfinates were examined and demonstrated the viability of this method. The mechanistic study showed that radical reactions occurred, while DABCO N-oxide radical can be observed by mass spectrometry. A plausible catalytic mechanism involving DABCO is also discussed, suggesting synergistic reduction of sulfinate by Cu(II) and DABCO is the key step of this coupling reaction. (Figure presented.).
Nickel-Catalyzed C?S Bond Formation via Decarbonylative Thioetherification of Esters, Amides and Intramolecular Recombination Fragment Coupling of Thioesters
Lee, Shao-Chi,Liao, Hsuan-Hung,Chatupheeraphat, Adisak,Rueping, Magnus
supporting information, p. 3608 - 3612 (2018/03/13)
A nickel catalyzed cross-coupling protocol for the straightforward C?S bond formation has been developed. Various mercaptans and a wide range of ester and amide substrates bearing various substituents were tolerated in this process which afforded products in good to excellent yields. Furthermore, an intramolecular protocol for the synthesis of thioethers starting from thioesters has been developed. The utility of this protocol has been demonstrated in a new synthetic protocol of benzothiophene.
Visible-light-promoted synthesis of diaryl sulfides under air
Hong, Boseok,Lee, Juyoung,Lee, Anna
supporting information, p. 2809 - 2812 (2017/06/27)
A convergent, organocatalytic visible-light-mediated process for the synthesis of diaryl sulfides has been developed. A broad range of aryl thiols reacted with various aryl diazonium salts in the presence of eosin Y under air atmosphere to afford the desired diaryl sulfides in high yields. This novel and environmentally friendly method provides an alternative route to established synthetic approaches.
Iron-catalyzed carbon–sulfur bond formation: Atom-economic construction of thioethers with diaryliodonium salts
Liu, Li,Qiang, Jian,Bai, Shuhua,Li, Yang,Li, Jian
, p. 2365 - 2371 (2017/09/30)
Diaryliodonium salts are characterized by poor atom economy with the formation of one equivalent of an iodoarene as waste. We have developed an atom-economic iron-catalyzed protocol for the synthesis of a variety of thioethers with diaryliodonium salts. Not only cyclic diaryliodonium salts but also linear diaryliodonium salts were found to perform well in the reactions.
A well-defined (POCOP)Rh catalyst for the coupling of aryl halides with thiols
Timpa, Samuel D.,Pell, Christopher J.,Ozerov, Oleg V.
supporting information, p. 14772 - 14779 (2015/01/16)
This article describes a well-defined pincer-Rh catalyst for C-S cross-coupling reactions. (POCOP)Rh(H)(Cl) serves as an active precatalyst for the coupling of aryl chlorides and bromides with aryl and alkyl thiols under reasonable conditions (3% mol cat., 110 °C, 2-24 h, >90% yield). For select substrates, >90% yields were obtained with catalyst loading as low as 0.1%. Key mechanistic intermediates have been isolated and fully characterized, including (POCOP)Rh(Ph)(SPh) (6a) and (POCOP)Rh(SPh2) (6b). The aryl/bis(phosphinite) (POCOP)Rh system has been shown to favor aryl thiolate reductive elimination at elevated temperatures and in some cases at room temperature, compared with the analogous diarylamido/bis(phosphine) (PNP)Rh pincer system. Concerted reductive elimination has been studied with 6a directly and in the presence of aryl bromide and aryl chloride traps. This investigation demonstrates a clear rate dependence on aryl chloride concentration during catalysis, a dependence that is absent when using aryl bromides. The rate of catalysis is dramatically reduced or brought to zero for ortho-tolyl halides, which can be traced to slower C-S coupling and slower carbon-halogen oxidative addition for ortho-substituted aryls. The influence of the sterics in the thiol component is less straightforward. The S-H oxidative addition product (POCOP)Rh(H)(SPh) (16) has been fully characterized and its reactivity has been examined, resulting in the isolation of the sodium-thiolate adduct (POCOP)Rh(NaSPh) (19). The solid-state structure of 19 shows Na interactions not only with sulfur, but also with a neighboring Rh and the chelating aryl carbon of the pincer framework. The reactivity of 16 and 19 indicates that these potential side products should not hinder catalysis.
