13448-97-0Relevant academic research and scientific papers
Oxidative rearrangement of flavanones with thallium(III) nitrate, lead tetraacetate and hypervalent iodines in trimethyl orthoformate and perchloric or sulfuric acid
Nemeth, Istvan,Kiss-Szikszai, Attila,Zita Illyes, Tuende,Mandi, Attila,Komaromi, Istvan,Kurtan, Tibor,Antus, Sandor
, p. 1289 - 1296 (2012)
An HPLC monitoring protocol has been developed to follow the reaction of flavanone [(±)-1] with thallium(III) nitrate, lead tetracetate, phenyliodonium diacetate (PIDA) or [hydroxyl(tosyloxy)iodo]benzene in trimethyl orthoformate. Besides the major ring-c
Electrochemical Cross-Dehydrogenative Coupling between Phenols and β-Dicarbonyl Compounds: Facile Construction of Benzofurans
Ding, Mengning,Shi, Zhuangzhi,Tian, Bailin,Wang, Yandong
supporting information, (2020/03/23)
Preparative electrochemical synthesis is an ideal method for establishing green, sustainable processes. The major benefits of an electro-organic strategy over that of conventional chemical synthesis are the avoidance of reagent waste and mild reaction conditions. Here, an intermolecular cross-dehydrogenative coupling between phenols and β-dicarbonyl compounds has been developed to build various benzofurans under undivided electrolytic conditions. Neither transition metals nor external chemical oxidants are required to facilitate the dehydrogenation and dehydration processes. The key factor in success was the use of nBu4NBF4 as the electrolyte and hexafluoroisopropanol as the solvent, which play key roles in the cyclocondensation step. This electrolysis is scalable and can be used as a key step in drug synthesis. On the basis of several experimental results, the mechanism, particularly of the remarkable anodic oxidation and cyclization process, was illustrated.
Application of phase-vanishing method with CO gas evolution to carbonylation reactions
Adachi, Yusuke,Matsubara, Hiroshi
supporting information, p. 89 - 95 (2018/10/26)
Although carbon monoxide (CO) is considered a practical source of the carbonyl functionality in various compounds, handling CO gas is difficult. The phase-vanishing (PV) method, using highly fluorinated solvents as the phase screen, was thus employed, in which CO was evolved for use in organic synthesis. An H-shaped reactor bearing two reaction chambers was employed. In the first chamber, CO was efficiently generated from sulfuric acid and ammonium formate under the PV conditions, and then consumed in the second chamber in a range of palladium-catalysed carbonylation reactions, affording the desired products. Use of this PV system allowed for easy and safe generation of hazardous CO gas, and its use thereof in organic synthesis.
Transition-Metal-Free Synthesis of 2-Substituted Methyl Benzo[b]furan-3-carboxylates
Kang, Byungsoo,Lee, Min Hyung,Kim, Mijung,Hwang, Jungwoon,Kim, Hyeong Baik,Chi, Dae Yoon
, p. 8254 - 8261 (2015/09/01)
A concise and highly efficient synthetic pathway was developed for 2-substituted methyl benzo[b]furan-3-carboxylates. This method provides convenient and cost-effective access for 2-substituted methyl benzo[b]furan-3-carboxylates without the use of a transition metal catalyst for synthesis. Furthermore, in most cases, this method gives excellent yields and conventional flash column chromatography is not needed for purification.
A concise route to dihydrobenzo[b]furans: Formal total synthesis of (+)-lithospermic acid
Fischer, Joshua,Savage, G. Paul,Coster, Mark J.
, p. 3376 - 3379 (2011/09/12)
A sequence of Sonogashira coupling, Pd(II)-catalyzed carbonylative annulation, and benzofuran reduction (Mg, MeOH, NH4Cl) provides a convergent and modular synthetic route to trans-2-aryl-2,3-dihydrobenzo[b]furan- 3-carboxylates, which are a structural feature of numerous biologically active natural products. This versatile strategy was applied to the formal total synthesis of the anti-HIV natural product (+)-lithospermic acid.
Gold(III)-catalyzed tandem reaction of O-arylhydroxylamines with 1,3-dicarbonyl compounds: Highly selective synthesis of 3-carbonylated benzofuran derivatives
Liu, Yunkui,Qian, Jianqiang,Lou, Shaojie,Xu, Zhenyuan
supporting information; experimental part, p. 6300 - 6303 (2010/11/18)
Figure presented. A highly regioselective protocol for the synthesis of 3-carbonylated benzofuran derivatives has been developed involving the gold(III)-catalyzed tandem condensation/rearrangement/cyclization reaction of O-arylhydroxylamines with 1,3-dicarbonyl compounds.
New insight into the mechanism of hypervalent iodine oxidation of flavanones
Juhász, László,Szilágyi, László,Antus, Sándor,Visy, Júlia,Zsila, Ferenc,Simonyi, Miklós
, p. 4261 - 4265 (2007/10/03)
Flavanone (1) on oxidation with iodobenzene diacetate (PIDA) in the presence of sulfuric acid in trimethyl orthoformate (TMOF) undergoes a stereospecific ring contraction by an aryl shift to result in trans methyl 2-aryl-2,3-dihydrobenzo[b]furan-3-carboxy
A new complex of palladium-thiourea and carbon tetrabromide catalyzed carbonylative annulation of o-hydroxylarylacetylenes: Efficient new synthetic technology for the synthesis of 2,3-disubstituted benzo[b]furans
Yang, Nan,Miao, Hua,Yang, Zhen
, p. 297 - 299 (2007/10/03)
(matrix presented) A highly effective cocatalysis system (Pdl2-thiourea and CBr4) was developed for carbonylative cyclization of both electron-rich and electron-deficient o-hydroxylarylacetylenes to the corresponding methyl benzo[b]f
A new approach to 2,3-disubstituted benzo[6]furans from o-alkynylphenols via 5-endo-rf?g-iodocyclisation/palladium-catarysed reactions
Arcadi, Antonio,Cacchi, Sandro
, p. 1432 - 1434 (2007/10/03)
The 5-endo-dig-iodocycization of o-alkynylphenols with iodine in the presence of NaHCO3 at room temperature produces functionalised 2-substituted-3-iodobenzo[t]furans, which are useful synthetic intermediates for the preparation of 2,3-disubstituted benzo[￡]furans via palladium-catalysed reactions. Thieme Stuttgart.
Hypervalent iodine oxidation of flavanones: A new synthesis of methyl 2-aryl-2,3-dihydrobenzofuran-3-carboxylates by 1,2-aryl shift
Prakash,Tanwar
, p. 1168 - 1171 (2007/10/02)
Flavanones (1), on oxidation with (diacetoxyiodo)benzene-sulfuric acid (DIB-H2SO4) or (hydroxy(tosyloxy)iodo)benzene (HTIB) in trimethyl orthoformate, undergo facile ring contraction by 1,2-aryl shift, thereby yielding methyl 2-aryl-2,3-dihydrobenzofuran-3-carboxylates (4) as major products (40-80%). cis-3-Methoxyflavanones (5) and flavones (3) are the minor products formed in variable ratios.
