29976-75-8Relevant academic research and scientific papers
Palladium-catalyzed synthesis of flavones and chromones via carbonylative coupling of o-iodophenols with terminal acetylenes
Kalinin,Shostakovsky,Ponomaryov
, p. 4073 - 4076 (1990)
o-Iodophenols react with terminal acetylenes under carbon monoxide in the presence of palladium catalyst to give flavones or 2-substituted chromones.
CF3SOCl-promoted intramolecular cyclization of β-diketones: An efficient synthesis of flavones
Sun, Dong-Wei,Zhou, Yong-Yan,Jiang, Min,Nian, Tang,Liu, Jin-Tao
, (2021/05/31)
An efficient intramolecular cyclization reaction of β-diketones containing a phenyl group with an ortho-hydroxyl substituent was achieved. Using CF3SOCl as an additive, the reaction took place under transition-metal-free and mild conditions. A series of flavones were synthesized in moderate to excellent yields.
An efficient TBHP/TBAI-mediated protocol for the synthesis of 4H-chromen-4-ones from chroman-4-ones via oxidative C–C bond formation
Agisho, Habtamu Abebe,Hairat, Suboot,Zaki, Mehvash
, p. 599 - 603 (2020/05/04)
Abstract: A transition metal-free and efficient TBHP/TBAI-mediated protocol has been developed for the synthesis of 4H-chromen-4-ones from chroman-4-ones via oxidative C–C bond formation. It proceeds in the presence of a catalytic amount of tetrabutylammonium iodide and oxidant tert-butyl hydroperoxide (TBHP, 5–6 M in decane) to afford the corresponding products in good to excellent yields. Furthermore, it has been observed that an increase in the concentration of TBHP to 30 mol % drastically increases the yield of 4H-chromen-4-ones, any further increase will lead to a decrease in percent yield. The mechanism of this reaction involves the generation of tertiary butoxide radical initially which by oxidative single-electron transformation is converted to iodochroman-4-one. Later the hydrogen iodide is removed from iodochroman-4-one to give the desired product, i.e. 4H-chromen-4-ones. Moreover, this is a rare example of the n-Bu4NI/TBHP-mediated C–C bond through dehydrogenative reaction. Graphic abstract: [Figure not available: see fulltext.]
Biocatalytic green alternative to existing hazardous reaction media: Synthesis of chalcone and flavone derivatives via the Claisen-Schmidt reaction at room temperature
Tamuli, Kashyap J.,Sahoo, Ranjan K.,Bordoloi, Manobjyoti
supporting information, p. 20956 - 20965 (2020/12/31)
Owing to the increasing amount of waste materials around the globe, the conversion of waste or secondary by-products to value-added products for various applications has gained significant interest. Herein, two novel agro-food waste products, Musa sp. 'Malbhog' peel ash (MMPA) and Musa Champa Hort. ex Hook. F. peel ash (MCPA) are used as catalysts to promote an inexpensive, efficient and eco-friendly carbon-carbon bond forming crossed aldol reaction at room temperature in solvent free conditions. Furthermore, the resulting products were subjected to reactions with these promoters in an oxygen atmosphere and led to the formation of novel flavone derivatives. Moreover, the used catalysts were properly characterized using different sophisticated analytical techniques such as Fourier-transform infrared spectroscopy (FT-IR), X-ray diffractometry (XRD), Brunauer-Emmett-Teller analysis (BET), Raman spectroscopy, scanning electron microscopy energy dispersive X-ray spectroscopy (SEM-EDS), transition electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) along with element detection using atomic absorption spectroscopy and ion chromatographic methods. These two approaches are metal free, as well as being devoid of any extra additives, co-catalysts, harsh conditions, the use of column chromatography for purification and result in a higher yield of the product within a short space of time. The catalytic abilities of the promoter were also examined to synthesize important bioactive molecules such as butein and apigenin at room temperature. With gram scale synthesis of the chalcone derivatives, the used catalysts (MMPA and MCPA) were further reused for five cycles and did not demonstrate any loss in catalytic activity.
Thermally regulated molybdate-based ionic liquids toward molecular oxygen activation for one-pot oxidative cascade catalysis
Song, Zhibin,Huang, Wei,Zhou, Yan,Tian, Zi-Qi,Li, Zhang-Min,Tao, Duan-Jian
, p. 103 - 109 (2020/01/21)
One-pot oxidative cascade catalysis plays a central role in the synthesis of key pharmaceutical and industrial molecules. Although ionic liquids are one of the most promising solvents and reaction media, the breakthrough of their catalysis in aerobic oxidation is very challenging due to the difficulty in the direct activation of molecular oxygen. Herein, a family of novel thermally regulated molybdate-based ionic liquids (Mo-ILs) has been designed and developed for the first time toward molecular oxygen activation for highly efficient tandem oxidative catalysis. Three diverse one-pot oxidative cascade processes for the syntheses of various flavones, imines, and benzyl benzoates were achieved with good to excellent yields using the Mo-IL [Bmim]2[MoO4] as a catalyst under air conditions. The results of spectroscopic investigations and quantum-chemical calculations further demonstrated that a thermally regulated proton migration between the cation [Bmim] and anion [MoO4] was the key to forming N-heterocyclic carbene and thereby to effortlessly promoting the generation of O2- active species from molecular oxygen, which results in excellent catalytic performance in these three aerobic tandem oxidations. Our work extends the application area of ILs as the sole catalyst to one-pot aerobic oxidative cascade catalysis, which could have pronounced implications in future work.
Single Step Synthetic Method for Homoisoflavonoids and Flavones
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Paragraph 0071; 0354-0358; 0360; 0362-0365; 0377-0380, (2019/09/12)
The present invention relates to a one-pot synthesis method of homoisoflavonoid derivatives and flavone derivatives. By conducting a reaction of salicylicaldehyde and arylalkynoic acid in the presence of a ruthenium catalyst and a base, homoisoflavonoids and flavones can be selectively obtained through a single step (one-pot). Therefore, a synthesis method of the present invention is a simple/disposable selective metal catalyst synthesis method, which can be used to manufacture a plurality of bioactive materials.COPYRIGHT KIPO 2019
Rh(III)-Catalyzed Aldehydic C?H Functionalization Reaction between Salicylaldehydes and Sulfoxonium Ylides
Xu, Guo-Dong,Huang, Kenneth L.,Huang, Zhi-Zhen
supporting information, p. 3318 - 3323 (2019/06/25)
A novel aldehydic C?H functionalization reaction between salicylaldehydes and sulfoxonium ylides has been developed under rhodium(III) catalysis, affording coupling products in moderate to good yields. A plausible mechanism involving aldehydic C(sp2)?H activation by rhodium(III) and rhodium(III) catalyzed carbene insertion is also proposed. It was also found that the aldehydic C?H functionalization followed by dehydrative cyclization was able to produce flavonoids in one-pot. (Figure presented.).
Rhodium(III)-catalyzed one-pot synthesis of flavonoids from salicylaldehydes and sulfoxonium ylides
Cheng, Kang,Chen, Jinkang,Jin, Licheng,Zhou, Jian,Jiang, Xinpeng,Yu, Chuanming
, p. 392 - 398 (2019/09/03)
Rh(III)-catalyzed C–H activation of salicylaldehyde followed by an insertion reaction with sulfoxonium ylides and cyclization is applied to the synthesis of flavonoids. This one-pot strategy exhibits good functional group tolerance and gives flavones in moderate-to-good yields.
An efficient tandem synthesis of chromones from: O -bromoaryl ynones and benzaldehyde oxime
Zhang, Jing-Wen,Yang, Wan-Wan,Chen, Lu-Lu,Chen, Pei,Wang, Yan-Bo,Chen, Dan-Yun
, p. 7461 - 7467 (2019/08/20)
An effective transition-metal-free strategy was developed for the preparation of chromones from o-bromoaryl ynones and benzaldehyde oxime through sequential C-O bond formation. This cyclization reaction could well tolerate a wide range of functional groups, and the corresponding chromones were given in moderate to excellent yields. Mechanistically, benzaldehyde oxime as a hydroxide source and 1,3-diketone derivatives as reaction intermediates were involved in this transformation.
One Pot Synthesis of γ-Benzopyranones via Iron-Catalyzed Aerobic Oxidation and Subsequent 4-Dimethylaminopyridine Catalyzed 6-endo Cyclization
Zhai, Di,Chen, Lingzhu,Jia, Minqiang,Ma, Shengming
, p. 153 - 160 (2017/11/23)
One-pot synthesis of γ-benzopyranones was realized in decent yields and excellent regioselectivities via iron-catalyzed aerobic oxidation and 4-dimethylaminopyridine-catalyzed cyclization of related propargylic alcohols. Derivatizations to aromatic substituted γ-benzopyranones and synthesis of naturally occurring 3′,4′-dimethoxyflavone have also been realized. (Figure presented.).
