2054-35-5Relevant academic research and scientific papers
An effective synthesis of fused cyclic thiopyrans and pyrans by molybdenum(VI) sulfide catalyzed reduction of the corresponding thiopyranones and pyranones
Takido,Takagi,Itabashi
, p. 687 - 690 (1995)
The synthesis of fused cyclic dihydrothiopyrans 2a-c from dihydrothiopyranones 1a-c and thiopyrans 2d-f from thiopyranones 1d-f by catalytic reduction over molybdenum(VI) sulfide (MoS3) has been studied. The hydrogenolysis of the carbonyl group of 1a-f over MoS3 catalyst proceeded selectively to give the corresponding 2a-f in high yields. Neither alcohols nor olefins were not detected in the products. The method was also applied successfully to the synthesis of dihydropyran 2h and pyran 2g from dihydropyranone 1h and pyranone 1g.
Cu-mediated: vs. Cu-free selective borylation of aryl alkyl sulfones
Hu, Jiefeng,Huang, Mingming,Marder, Todd B.,Radius, Udo,Tang, Man,Westcott, Stephen A.
, p. 395 - 398 (2022/01/19)
A Cu-catalysed borylation of aryl alkyl sulfones was developed for the high yield synthesis of versatile arylboronic esters using a readily prepared NHC-Cu catalyst. In addition, the selective cleavage of either alkyl(C)-sulfonyl or aryl(C)-sulfonyl bonds
Direct Access to S-Heterocycles by Scandium(III) Triflate Catalyzed Cyclization of Aromatic Thiols and Diols
Minakawa, Maki,Minami, Keisuke,Sato, Yuya
supporting information, p. 1869 - 1873 (2021/07/31)
A simple and environmentally friendly method to prepare S-heterocycles by cyclization of aromatic thiols and diols with H2O as a byproduct is described. The Sc(OTf)3-catalyzed dehydrative cyclizations of aromatic thiols and diols provided the corresponding thiopyran and thiophene derivatives. Control experiments were also performed to obtain insights into the reaction pathway.
Investigating the microwave-accelerated Claisen rearrangement of allyl aryl ethers: Scope of the catalysts, solvents, temperatures, and substrates
Hui, Zi,Jiang, Songwei,Qi, Xiang,Ye, Xiang-Yang,Xie, Tian
supporting information, (2020/05/18)
The microwave-accelerated Claisen rearrangement of allyl aryl ethers was investigated, in order to gain insight into the scope of the catalysts, solvents, temperatures, and substrates. Among the catalysts examined, phosphomolybdic acid (PMA) was found to greatly accelerate the reaction in NMP, at temperatures ranging from 220 to 300 °C. This method was found to be useful for preparing several intermediates previously reported in the literature using precious metal catalysts such as Au(I), Ag(I), and Pt(II). Additionally, substrates bearing bromo and nitro groups on the aryl portion required careful tailoring of the reaction conditions to avoid complex product profiles.
Nickel-Catalyzed Inter- and Intramolecular Aryl Thioether Metathesis by Reversible Arylation
Delcaillau, Tristan,Bismuto, Alessandro,Lian, Zhong,Morandi, Bill
supporting information, p. 2110 - 2114 (2019/12/24)
A nickel-catalyzed aryl thioether metathesis has been developed to access high-value thioethers. 1,2-Bis(dicyclohexylphosphino)ethane (dcype) is essential to promote this highly functional-group-tolerant reaction. Furthermore, synthetically challenging macrocycles could be obtained in good yield in an unusual example of ring-closing metathesis that does not involve alkene bonds. In-depth organometallic studies support a reversible Ni0/NiII pathway to product formation. Overall, this work not only provides a more sustainable alternative to previous catalytic systems based on Pd, but also presents new applications and mechanistic information that are highly relevant to the further development and application of unusual single-bond metathesis reactions.
Mo-Based Oxidizers as Powerful Tools for the Synthesis of Thia- and Selenaheterocycles
Franzmann, Peter,Beil, Sebastian B.,Schollmeyer, Dieter,Waldvogel, Siegfried R.
, p. 1936 - 1940 (2019/01/14)
A highly efficient synthetic protocol for the synthesis of thia- and selenaheterocycles has been developed. By employing a MoCl5-mediated intramolecular dehydrogenative coupling reaction, a broad variety of structural motifs was isolated in yields up to 94 %. The electrophilic key transformation is tolerated by several labile moieties like halides and tertiary alkyl groups. Due to the use of disulfide or diselenide precursors, a high atom efficiency was achieved.
Chlorotrimethylsilane and Sodium Iodide: A Remarkable Metal-Free Association for the Desulfurization of Benzylic Dithioketals under Mild Conditions
Zhao, Guangkuan,Yuan, Ling-Zhi,Alami, Mouad,Provot, Olivier
, p. 2522 - 2536 (2018/05/14)
A novel metal-free process allowing the reductive desulfurization of various benzylic dithioketals to afford diarylmethane and benzylester derivatives with good to excellent yields is reported. At room temperature, this mild reduction process requires only the use of TMSCl and NaI in CH2Cl2 and tolerates a large variety of functional groups. (Figure presented.).
Efficient access to 1,4-benzothiazine: Palladium-catalyzed double C-S bond formation using Na2S2O3 as sulfurating reagent
Qiao, Zongjun,Liu, Hui,Xiao, Xiao,Fu, Yana,Wei, Jianpeng,Li, Yuxue,Jiang, Xuefeng
supporting information, p. 2594 - 2597 (2013/07/19)
A novel Pd-catalyzed double C-S bond formation coupling reaction has been developed. This protocol, in which Na2S2O3 was used as sulfurating reagent in metal-catalyzed reactions, provides an efficient method for the synthe
Novel chiral, sulfur-containing heteroarotinoids with liquid crystal properties
Weerasekare, G. Mahika,Berlin, K. Darrell,Sunkara, Haribabu,Ford, Warren T.
, p. 993 - 1006 (2007/10/03)
Synthetic methods were developed to prepare ethyl (E)-4-[2-(3,4-dihydro-2-n-octyl-1-oxy-2H-1-benzothio-pyran-6-yl)-1- propenyl]-benzoate (1) and ethyl ( E)-4-[2-(3,4-dihydro-2-n-octyl-2H-1-benzothiopyran-6-yl)-1-propenyl]benzoate (10). These are the first examples of heteroarotinoids which possess properties of liquid crystals. The properties were evaluated using differential scanning calorimetry and by use of polarizing micrography. Both displayed textures which are typical of a smectic or cholesteric phase.
Biologically active heteroarotinoids exhibiting anticancer activity and decreased toxicity
Benbrook, Doris M.,Madler, Matora M.,Spruce, Lyle W.,Birckbichler, Paul J.,Nelson, Eldon C.,Subramanian, Shankar,Mahika Weerasekare,Gale, Jonathan B.,Patterson Jr., Manford K.,Wang, Binghe,Wang, Wei,Lu, Shennan,Rowland, Tami C.,DiSivestro, Paul,Lindamood III, Charles,Hill, Donald L.,Berlin, K. Darrell
, p. 3567 - 3583 (2007/10/03)
A series of retinoids, containing heteroatoms in a cyclic ring and called heteroarotinoids, were synthesized, and their biological activity was evaluated using tissue culture lines that have measurable responses to trans- retinoic acid (t-RA). Transglutam
