5912-89-0Relevant academic research and scientific papers
Catalytic SNAr Hydroxylation and Alkoxylation of Aryl Fluorides
Kang, Qi-Kai,Li, Ke,Li, Yuntong,Lin, Yunzhi,Shi, Hang,Xu, Lun
supporting information, p. 20391 - 20399 (2021/08/13)
Nucleophilic aromatic substitution (SNAr) is a powerful strategy for incorporating a heteroatom into an aromatic ring by displacement of a leaving group with a nucleophile, but this method is limited to electron-deficient arenes. We have now established a reliable method for accessing phenols and phenyl alkyl ethers via catalytic SNAr reactions. The method is applicable to a broad array of electron-rich and neutral aryl fluorides, which are inert under classical SNAr conditions. Although the mechanism of SNAr reactions involving metal arene complexes is hypothesized to involve a stepwise pathway (addition followed by elimination), experimental data that support this hypothesis is still under exploration. Mechanistic studies and DFT calculations suggest either a stepwise or stepwise-like energy profile. Notably, we isolated a rhodium η5-cyclohexadienyl complex intermediate with an sp3-hybridized carbon bearing both a nucleophile and a leaving group.
Carbonyl–Olefin Cross-Metathesis Through a Visible-Light-Induced 1,3-Diol Formation and Fragmentation Sequence
Pitzer, Lena,Sandfort, Frederik,Strieth-Kalthoff, Felix,Glorius, Frank
supporting information, p. 16219 - 16223 (2018/11/23)
A visible-light-mediated approach to carbonyl–olefin cross-metathesis is described. Photoinduced hole catalysis was used to promote the formation of 1,3-diols from aldehydes and styrenes, which were then readily fragmented under acidic conditions to form the cross-metathesis products. The use of 1,3-diols as intermediates, rather than the energetically more demanding oxetanes, provides a new, orthogonal mechanistic strategy for carbonyl–olefin cross-metathesis. Furthermore, this approach does not require any metals, ligands, or additives, and provides the products with high levels of E selectivity. A mechanistic rationale is provided and supported by both theoretical calculations and experiments. Additionally, a practical synthesis of a new acridinium-based photocatalyst, including full characterization, is presented.
Biphenylsulfonamide endothelin antagonists: Structure-activity relationships of a series of mono- and disubstituted analogues and pharmacology of the orally active endothelin antagonist 2'-amino-N-(3,4- dimethyl-5-isoxazolyl)-4'-(2-methylpropyl)[1,1'-biphenyl]-2-sulfonamide (BMS- 187308)
Murugesan, Natesan,Gu, Zhengxiang,Stein, Philip D.,Bisaha, Sharon,Spergel, Steve,Girotra, Ravi,Lee, Ving G.,Lloyd, John,Misra, Raj N.,Schmidt, Joan,Mathur, Arvind,Stratton, Leslie,Kelly, Yolanda F.,Bird, Eileen,Waldron, Tom,Liu, Eddie C.-K.,Zhang, Rongan,Lee, Helen,Serafino, Randy,Abboa-Offei, Benoni,Mathers, Parker,Giancarli, Mary,Seymour, Andrea Ann,Webb, Maria L.,Moreland, Suzanne,Barrish, Joel C.,Hunt, John T.
, p. 5198 - 5218 (2007/10/03)
Substitution at the ortho position of N-(3,4-dimethyl-5-isoxazolyl) benzenesulfonamide led to the identification of the biphenylsulfonamides as a novel series of endothelin-A (ETA) selective antagonists. Appropriate substitutions on the pendant phenyl ring led to improved binding as well as functional activity. A hydrophobic group such as isobutyl or isopropoxyl was found to be optimal at the 4'-position. Introduction of an amino group at the 2'-position also led to improved analogues. Combination of the optimal 4'- isobutyl substituent with the 2'-amino function afforded an analogue (20, BMS-187308) with improved ET(A) binding affinity and functional activity. Compound 20 also has good oral activity in inhibiting the pressor effect caused by an ET-1 infusion in rats. Doses of 10 and 30 μmol/kg iv 20 attenuated the pressor responses due to the administration of exogenous ET-1 to conscious monkeys, indicating that the compound inhibits the in vivo activity of endothelin-1 in nonhuman primates.
