3279-07-0Relevant articles and documents
Coumarin synthesis on π-acidic surfaces
Miros, Fran?ois N.,Huang, Guangxi,Zhao, Yingjie,Sakai, Naomi,Matile, Stefan
, p. 303 - 309 (2015)
Catalysis with anion-π interactions is emerging as an important topic in supramolecular chemistry. Among the reactions explored so far on π-acidic surfaces, coumarin synthesis stands out as a cascade process with several coupled anionic transition states. Increasing π-acidity has been shown in a different context to increase transition-state stabilisation and thus catalytic activity. In this report, we explore the possible use of macrocycles to accelerate coumarin synthesis between two π-acidic surfaces. To our disappointment, we found that compared to monomeric π-acids, coumarin synthesis within divalent macrocycles is clearly slower. Hindered access to an overly confined active site within the macrocycles could possibly account for this loss in activity, but several other explanations are certainly possible. However, operational coumarin synthesis on monomeric π-acidic surfaces is shown to tolerate structural modifications. Best results are obtained with structures that aim for proximity without obstructing transition-state stabilisation on the π-acidic surface.
Nitration method for aryl phenol or aryl ether derivative
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Paragraph 0050-0055; 0071-0073, (2020/01/03)
The invention relates to a nitration method for an aryl phenol or aryl ether derivative. The method comprises the steps of stirring an aryl phenol or aryl ether compound, nitrate, trimethylchlorosilane (TMSCl) and a copper salt in an acetonitrile solution in air at room temperature, simultaneously, monitoring extent of reaction through a TLC dot plate, removing a solvent from a mixture by a rotaryevaporator after a substrate is consumed completely, and carrying out purification through a silica-gel column, thereby obtaining a nitroolefin derivative. Meanwhile, the selective mono-nitration orbis-nitration of the substrate can be achieved through controlling equivalent weight of the nitrate. Compared with the prior art, the nitration method disclosed by the invention has the advantages that the consumption of strong-acid substances is avoided, the reaction conditions are mild, the yield is high, the applicable range of the substrate is wide, reaction activity is free of obvious attenuation after an amplified reaction, and an excellent yield is still obtained, so that the method has an obvious industrial application value.
Research on unique masked ortho-benzoquinone, monohemiaminal: Synthesis and reactions
Matsumoto, Yuri,Nakamura, Akihiko,Saito, Emi,Nakada, Masahisa
, p. 232 - 252 (2019/04/27)
Synthesis of ortho-benzoquinone monohemiaminals via the oxidative dearomatization/O-cyclization cascades of phenols bearing an ortho substituent derived from an amino alcohol with PIDA is described. The cascade reactions of substrates bearing a chiral substituent were found to proceed in a stereoselective manner. The Diels-Alder reactions of the ortho-benzoquinone monohemiaminals proceed in a highly stereoselective manner. The oxidative dearomatization/O-cyclization cascade affording the ortho-benzoquinone monohemiaminal had never been reported; hence, there is still ample scope for further investigation.
