26820-94-0Relevant articles and documents
PROCESS FOR FORMING A CARBON-CARBON BOND
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Page/Page column 73-74, (2019/11/28)
A process for forming a carbon-carbon bond to couple an aryl or heteroaryl group of a first compound with an aryl or heteroaryl group of a second compound, the process comprising reacting the first compound with the second compound in the presence of a catalytically effective amount of a neutral or cationic ruthenium(II) catalyst of formula (I):
Lewis acid-mediated defluorinative [3+2] cycloaddition/aromatization cascade of 2,2-difluoroethanol systems with nitriles
Hsieh, Min-Tsang,Lee, Kuo-Hsiung,Kuo, Sheng-Chu,Lin, Hui-Chang
, p. 1605 - 1610 (2018/03/05)
The properties of C?F bonds, including high thermal and chemical stability, make derivatization of organic fluorine-containing compounds by the activation of the C?F bond and subsequent functionalization quite challenging. We herein report a Lewis acid-mediated defluorinative cycloaddition/aromatization cascade of 2,2-difluoroethanols with nitriles as a novel synthetic method for the preparation of 2,4,5-trisubstituted oxazoles. This reaction, which involves cleavage of two C?F bonds and the consecutive formation of C?O and C?N bonds in a one-pot fashion, features a broad substrate scope and moderate to high reaction yields. Mechanistic studies revealed that the reaction is initiated by the Lewis acid-mediated ring closure of the 2,2-difluoroethanol to produce the fluoroepoxide intermediate. (Figure presented.).
Metal-free syntheses of oxazoles and their analogues based on λ3-iodane-mediated cycloisomerization/functionalization reactions or [2+2+1] cycloaddition type reactions
Saito, Akio
, p. 84 - 98 (2017/04/17)
As a metal-free construction of oxazoles and furans concomitant with the introduction of oxygen functional groups or fluorine atoms into the side chains, we have developed λ3-iodane-mediated cycloisomerization/functionalization reactions of propargyl compounds. In these reactions, aryl- λ3-iodane ArI(X)Y works not only as a donor of heteroatomic functional groups but also as an activator of carbon-carbon triple bonds. Therefore, this methodology is not required any transition metal catalysts, which are frequently used in previous methods. Furthermore, this methodology can be extended to λ3-iodane-mediated [2+2+1] cycloaddition type reactions of alkynes, nitriles and heteroatoms for metal-free formation of oxazoles and imidazoles.
Synthesis of Extended Oxazoles III: Reactions of 2-(Phenylsulfonyl)methyl-4,5-diaryloxazoles
Patil, Pravin C.,Luzzio, Frederick A.
, p. 10521 - 10526 (2016/11/17)
2-((Phenylsulfonyl)methyl)-4,5-diphenyloxazole is a useful scaffold for synthetic elaboration at the 2-methylene position thereby affording extended oxazoles. The corresponding α-sulfonyl anion reacts smoothly with diverse alkyl halides giving monoalkylated (47-90%), dialkylated (50-97%), and cyclic (59-93%) products. The reductive desulfonylation of the monoalkylated and selected dialkylated products was optimized with a magnesium/mercuric chloride reagent system and afforded desulfonylated products in the range of 66-97%. The anti-inflammatory Oxaprozin was prepared using the α-sulfonyl carbanion strategy along with optimized desulfonylation.
Metal-free [2 + 2 + 1] annulation of alkynes, nitriles, and oxygen atoms: Iodine(III)-mediated synthesis of highly substituted oxazoles
Saito, Akio,Taniguchi, Akihiro,Kambara, Yui,Hanzawa, Yuji
supporting information, p. 2672 - 2675 (2013/07/19)
The metal-free [2 + 2 + 1] annulation of alkynes, nitriles, and O-atoms for the regioselective assembly of 2,4-disubstituted and 2,4,5-trisubstituted oxazole compounds has been achieved by the use of PhIO with TfOH or Tf 2NH. The present reaction could be applied to a facile synthesis of an anti-inflammatory drug.
Synthesis of oxazoles from enamides via phenyliodine diacetate-mediated intramolecular oxidative cyclization
Zheng, Yunhui,Li, Xuming,Ren, Chengfeng,Zhang-Negrerie, Daisy,Du, Yunfei,Zhao, Kang
, p. 10353 - 10361 (2013/01/15)
A group of functionalized oxazoles were synthesized in moderate to good yields from enamides via phenyliodine diacetate (PIDA)-mediated intramolecular cyclization. The main advantageous features of the present method include its broad substrate scope and the heavy-metal-free characteristic of the oxidative carbon-oxygen bond formation process.
Synthesis of Oxazoles by the Reaction of Ketones with Iron(III) Solvates of Nitriles
Kotani, Eiichi,Kobayashi, Shigeki,Adachi, Mayumi,Tsujioka, Toshiyuki,Nakamura, Kouji,Tobinaga, Seisho
, p. 606 - 609 (2007/10/02)
Oxazoles having functionalized carbon substituents at the C-2 position were synthesized in one step by the oxidation of ketones with iron(III) solvates of nitriles, i.e., Fe(RCN)6(ClO4)3(solvate A) or Fe(RCN)6)FeCl4)3(solvate B), in the corresponding nitriles.Keywords oxazole; ketone; oxidation; nitrile; iron(III) nitrile solvate
