4732-72-3Relevant academic research and scientific papers
TBN-triggered, manipulable annulations of: O -hydroxyarylenaminones for divergent syntheses of oximinochromanones and oximinocoumaranones
Chen, Kai,Qian, Yu-En,Xiang, Hao-Yue,Xiao, Jun-An,Yang, Hua,Zhao, Qing-Lan,Zheng, Lan
, p. 12285 - 12288 (2021/12/07)
Divergent synthesis provides an indispensable route to rapid acquisition of structurally diverse chemical scaffolds from identical starting materials. Herein, we describe unprecedented divergent annulations of o-hydroxyarylenaminones promoted by tert-butyl nitrite (TBN) under mild conditions. Two different types of benzo-oxa-heterocycle, including oximinochromanones and oximinocoumaranones, were smoothly assembled with a broad substrate scope and good functional group compatibility.
Preparing method and application for coumarone- 2,3- diketone oxime derivative
-
Paragraph 0031; 0032, (2017/04/21)
The invention discloses a preparing method and application for coumarone- 2, 3- diketone oxime derivative. The invention uses 3- formylchromone derivatives as the initiator and the raw materials are easy to get with multiple types and the industrial sodium nitrite as the reaction reagent at low cost; products obtained through the invention are diversified and can be widely applied in drug synthesis of bactericide, sanitizer, drugs for Alzheimer's disease treatment, drugs to restrain hepatitis C virus, SIRT1 and cancer cell proliferation in vitro, etc. In addition, for the method disclosed in the invention, reaction is performed in the air, namely room temperature reaction. The target product has high yield coefficient, low pollution, and simple reaction operation and post-processing, which is suitable for industrial production.
A Serendipitous Synthesis of Bis-Heterocyclic Spiro 3(2 H)-Furanones
Picado, Alfredo,Li, ShengJian,Dieter, R. Karl
, p. 1391 - 1400 (2016/03/01)
(Z) Enol triflates 6, 11b-d, (E) enol triflate 11e, and phenol triflate 11a, derived from β-keto esters or 2-carboalkoxy phenols, respectively, react with N-Boc 2-lithiopyrrolidine (5a), N-Boc N-methylaminomethyllithium (5b), or 2-lithio-1,3-dithiane (14) to afford 3(2H)-furanones in modest to good yields (38-81%). Product and carbanion reagent studies suggest that the 3(2H)-furanone is formed in a cascade of reactions involving nucleophilic acyl substitution, enolate formation, trifluoromethyl transfer, iminium or sulfenium ion formation, and subsequent ring closure to form the 3(2H)-furanone. The use of 2-lithio-1,3-dithiane affords a cyclic α-keto-S,S,O-orthoester in which the functionality can be selectively manipulated for synthetic applications. (Chemical Equation Presented).
Asymmetric construction of spirocyclopentenebenzofuranone core structures via highly selective phosphine-catalyzed [3 + 2] cycloaddition reactions
Albertshofer, Klaus,Tan, Bin,Barbas III, Carlos F.
supporting information, p. 2958 - 2961 (2013/07/26)
An efficient organocatalytic asymmetric [3 + 2] cycloaddition reaction between 3-substituted methylenebenzofuranone derivatives and diverse Morita-Baylis-Hillman carbonates to provide complex polysubstituted spirocyclopentenebenzofuranone scaffolds in a single step is reported. C2-symmetric phospholanes were efficient nucleophilic catalysts of this transformation under mild conditions, providing reaction products comprised of three consecutive stereocenters, including one all-carbon center, with excellent enantioselectivity.
Photolysis of indan-l,2-dione derivatives in oxygen-doped argon matrix at low temperature
Itoh, Takayoshi,Tatsugi, Jiro,Tomioka, Hideo
experimental part, p. 475 - 481 (2009/08/07)
Photolysis of indan-l,2,3-trion (la), benzo[ft]furan-2,3-dione (lb), and N-methylisatin (1c) in argon matrix either with or without oxygen at 10 K was investigated by IR spectroscopy in combination with DFT calculations. The results indicate that while 1a and 1b gave the products mixture as a result of α-cleavage, followed by decarbonylation, 1c was rather photostable under similar conditions. However, when the irradiation was carried out in argon matrix doped with 20% oxygen, 1c decomposed much more efficiently than that in argon matrix and cyclic diacyl peroxide presumably formed by trapping of initial diradical originating from α-cleavage by molecular oxygen was detected. Similar irradiation of 1b also gave cyclic diacyl peroxide along with photodecarbonylation products, but irradiation of 1a in oxygen-doped matrix produced not only cyclic diacyl peroxide but also products as a result of oxidation of photodecarbonylation product. The present observation reveals that photolysis of ketones in oxygen-doped matrix at low temperature provides useful information concerning the reactivities of ketones toward α-cleavage.
Photoreactions of 3-Diazo-3H-benzofuran-2-one; Dimerization and Hydrolysis of Its Primary Photoproduct, A Quinonoid Cumulenone: A Study by Time-Resolved Optical and Infrared Spectroscopy
Chiang, Yvonne,Gaplovsky, Martin,Kresge, A. Jerry,Leung, King Hung,Ley, Christian,Mac, Marek,Persy, Gabriele,Phillips, David L.,Popik, Vladimir V.,Roedig, Christoph,Wirz, Jakob,Zhu, Yu
, p. 12872 - 12880 (2007/10/03)
Light-induced deazotization of 3-diazo-3H-benzofuran-2-one (1) in solution is accompanied by facile (CO)-O bond cleavage yielding 6-(oxoethenylidene)-2,4-cyclohexadien-1-one (3), which appears with a rise time of 28 ps. The expected Wolff-rearrangement product, 7-oxabicyclo[4.2.0]octa-1,3,5-trien-8-ylidenemethanone (4), is not formed. The efficient light-induced formation of the quinonoid cumulenone 3 opens the way to determine the reactivity of a cumulenone in solution. The reaction kinetics of 3 were monitored by nanosecond flash photolysis with optical (λ max ≈ 460 nm) as well as Raman (1526 cm-1) and IR detection (2050 cm-1). Remarkably, the reactivity of 3 is that expected from its valence isomer, the cyclic carbene 3H-benzofuran-2-one-3-ylidene, 2. In aqueous solution, acid-catalyzed addition of water forms the lactone 3-hydroxy-3H-benzofuran-2-one (5). The reaction is initiated by protonation of the cumulenone on its β-carbon atom. In hexane, cumulenone 3 dimerizes to isoxindigo ((E)-[3,3′ ]bibenzofuranylidene-2,2′-dione, 7), coumestan (6H-benzofuro[3,2-c][1]benzopyran-6-one, 8), and a small amount of dibenzonaphthyrone ([1]benzopyrano[4,3-][1]benzopyran-5,11-dione, 9) at a nearly diffusion-controlled rate. Ab initio calculations (G3) are consistent with the observed data. Carbene 2 is predicted to have a singlet ground state, which undergoes very facile, strongly exothermic (irreversible) ring opening to the cumulenone 3. The calculated barrier to formation of 4 (Wolff-rearrangement) is prohibitive. DFT calculations indicate that protonation of 3 on the β-carbon is accompanied by cyclization to the protonated carbene 2H +, and that dimerization of 3 to 7 and 9 takes place in a single step with negligible activation energy.
Kinetics and mechanism of hydrolysis of 3-diazobenzofuran-2-one and its hydrolysis product (3-hydroxybenzofuran-2-one)
Chiang,Kresge,Meng
, p. 82 - 88 (2007/10/03)
Rates of acid-catalyzed hydrolysis of 3-diazobenzofuran-2-one, measured in concentrated aqueous perchloric acid and hydrochloric acid solutions, were found to correlate well with the Cox-Yates Xo excess acidity function, giving kH+ = 1.66 × 10-4 M-1 s-1, m? = 0.86 and kH+/kD+ = 2.04. The normal direction (kH/kD > 1) of this isotope effect indicates that hydrolysis occurs by rate-determining protonation of the substrate on its diazo-carbon atom. It was found previously that the next higher homolog of the present substrate, 4-diazoisochroman-3-one, also undergoes hydrolysis by this reaction mechanism but with a rate constant 15 times greater than that for the present substrate; this difference in reactivity can be understood in terms of the various resonance forms that contribute to the structures of these substrates. The product of the present hydrolysis reaction is 3-hydroxybenzofuran-2-one, which itself quickly undergoes subsequent acid-catalyzed hydrolysis to 2-hydroxymandelic acid. The acidity dependence of this subsequent hydrolysis is much shallower than that of the diazo compound precursor, and rates of reaction correlate as well with [H+] as with Xo. This is due in part to incursion of a nonproductive protonation on the hydroxy group of 3-hydroxybenzofuran-2-one that impedes hydrolysis and produces saturation of acid catalysis. Rates of hydrolysis of the hydroxy compound were also measured in dilute HClO4 and NaOH solutions as well as in CH3CO2H, H2PO4-, (CH2OH)3CNH3-, and NH4- buffers, and the rate profile constructed from these data showed the presence of uncatalyzed and hydroxide ion-catalyzed reactions. This hydroxide-ion catalysis became saturated at [NaOH] ? 0.05 M, implying occurrence of yet another nonproductive substrate ionization.
