112004-82-7Relevant academic research and scientific papers
Nickel-Catalyzed Cross-Coupling of Aryl Pivalates with Cyclobutanols Involving C—O and C—C Bond Cleavage?
Gan, Yi,Zhang, Ninghui,Huang, Shaoxu,Liu, Yuanhong
, p. 1686 - 1690 (2020)
An efficient nickel-catalyzed cross-coupling of aryl pivalates with cyclobutanols is described. The use of Ni(cod)2/PCy3/base as the catalytic system enables the cleavage of inert C—O bond and C—C bond under mild conditions, thus providing a facile access to γ-arylated ketones in generally good to excellent yields. This transformation is also characterized by wide substrate scope and functional group compatibility, for example, methoxy, N,N-dimethylamino, keto, ester, fluoro and TMS groups are well-tolerated during the reaction process.
Nickel-Mediated Trifluoromethylation of Phenol Derivatives by Aryl C?O Bond Activation
Hu, Wei-Qiang,Pan, Shen,Qing, Feng-Ling,Vicic, David A.,Xu, Xiu-Hua
supporting information, p. 16076 - 16082 (2020/07/04)
The increasing pharmaceutical importance of trifluoromethylarenes has stimulated the development of more efficient trifluoromethylation reactions. Tremendous efforts have focused on copper- and palladium-mediated/catalyzed trifluoromethylation of aryl halides. In contrast, no general method exists for the conversion of widely available inert electrophiles, such as phenol derivatives, into the corresponding trifluoromethylated arenes. Reported herein is a practical nickel-mediated trifluoromethylation of phenol derivatives with readily available trimethyl(trifluoromethyl)silane (TMSCF3). The strategy relies on PMe3-promoted oxidative addition and transmetalation, and CCl3CN-induced reductive elimination. The broad utility of this transformation has been demonstrated through the direct incorporation of trifluoromethyl into aromatic and heteroaromatic systems, including biorelevant compounds.
Chemoselective Cross-Coupling between Two Different and Unactivated C(aryl)-O Bonds Enabled by Chromium Catalysis
Tang, Jinghua,Liu, Liu Leo,Yang, Shangru,Cong, Xuefeng,Luo, Meiming,Zeng, Xiaoming
supporting information, p. 7715 - 7720 (2020/05/20)
We report here the first example of cross-coupling between two different and unactivated C(aryl)-O bonds with chromium catalysis. The combination of a low-cost Cr(II) salt, 4,4′-di-tert-butyl-2,2′-dipyridyl (dtbpy) as the ligand, and magnesium as the reductant shows high reactivity in promoting the reductive cross-coupling of aryl methyl ether derivatives with aryl esters by cleavage and coupling of two different C(aryl)-O bonds under mild conditions. The formation of active low-valent Cr species by reduction of CrCl2 with Mg can be considered, which prefers to initially activate the C(aryl)-O bond of phenyl methyl ether with the chelation help of dtbpy and an o-imine auxiliary. The subsequent consecutive reduction, second C(aryl)-O activation, and reductive elimination allow for the achievement of selective cross-coupling of C(aryl)-O/C(aryl)-O bonds.
Ni/Ti Dual Catalytic Cross-Coupling of Nitriles and Organobromides to Access Ketones
Chenniappan, Vinoth Kumar,Silwal, Sajan,Rahaim, Ronald J.
, p. 4539 - 4544 (2018/05/23)
Herein, we report the development of a dual catalytic approach for the cross-coupling of nitriles with aryl- and aliphatic-bromides. A titanium(III) catalyst is used to activate nitriles enabling their coupling with organobromides through a nickel catalyst. The Ni/Ti system efficiently prepared unsymmetrical ketones with good chemoselectivity and could selectively couple a bromide in the presence of other functionalizable handles.
Non-peptidic inhibitors of human neutrophil elastase: The design and synthesis of sulfonanilide-containing inhibitors
Imaki, Katsuhiro,Okada, Takanori,Nakayama, Yoshisuke,Nagao, Yuuki,Kobayashi, Kaoru,Sakai, Yasuhiro,Mohri, Tetsuya,Amino, Takaaki,Nakai, Hisao,Kawamura, Masanori
, p. 2115 - 2134 (2007/10/03)
A novel series of pivaloyloxy benzene derivatives has been identified as potent and selective human neutrophil elastase (HNE) inhibitors. Convergent syntheses were developed in order to identify the inhibitors which are intravenously effective in an animal model. A compound of particular interest is the sulfonanilide-containing analogues. Structure-activity relationships are discussed. Structural requirements for metabolic stabilization are also discussed.
(Acyloxy)benzophenones and (Acyloxy)-4-pyrones. A New Class of Inhibitors of Human Neutrophil Elastase
Miyano, Masateru,Deason, James R.,Nakao, Akira,Stealey, Michael A.,Villamil, Clara I.,et al.
, p. 1052 - 1061 (2007/10/02)
A series of 4-(acyloxy)- and 4,4'-bis(acyloxy)benzophenones were synthesized.Some of them, pivalates (trimethylacetates) and isobutyrates in particular, were found to be potent and selective inhibitors of human neutrophil (leukocyte) elastase.A series of 2--5-(acyloxy)-4-pyrones were synthesized regioselectively from kojic acid.The 4-pyrones bearing a long chain acyl group at the 2-position and either pivaloyloxy or isobutyryloxy at the 5-position were potent and selective inhibitors of the human elastase.A number of analogues and derivatives in both series were synthesized in order to study the structure-activity relationship as summarized in Tables I-VI and in Tables IX and X.The inhibition was selective to human neutrophil elastase.No inhibition of porcine pancreatic elastase or bovine pancreatic chymotrypsin (Tables VII and XI) was observed.The most likely mechanism of inhibition is discussed.The implication of these findings for the treatment of rheumatoid arthritis and emphysema is outlined.
PHENOLIC ESTER DERIVATIVES AS ELASTASE INHIBITORS
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, (2008/06/13)
Phenolic esters of the general formula I STR1 are useful for the prevention, management or alleviation of elastase mediated diseases or conditions.
