66074-95-1Relevant academic research and scientific papers
Attrition-enhanced deracemization and absolute asymmetric synthesis of flavanones from prochiral precursors
Kasashima, Yoshio,Mino, Takashi,Sakamoto, Masami,Shimizu, Waku,Uemura, Naohiro,Yoshida, Yasushi
, p. 5676 - 5681 (2020/10/13)
Seven racemic 5,7-dimethoxyflavanones afforded conglomerate crystals upon recrystallization from a solvent. Three methodologies were investigated to achieve asymmetric transformation based on dynamic crystallization of the chiral conglomerate system. The first was chiral symmetry breaking of racemic flavanones by attrition-enhanced deracemization. Continuous suspension of racemic flavanones in a small amount of propanol in the presence of a base (1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)) and glass beads promoted chiral symmetry breaking and converted the flavanones to crystals of (+)- or (-)-enantiomers with 78 to 99% ee. The second method involved cyclization of the intermediate aldol product to give optically active flavanone with 90% ee involving a reversible oxa-Michael addition reaction with attrition-enhanced deracemization. The third was a reaction starting from prochiral 2-hydroxy-4,6-dimethoxyacetophenone and 2-naphthaldehyde under basic conditions, which gave the corresponding flavanone in 89% ee.
Synthesis of Flavanones via Palladium(II)-Catalyzed One-Pot β-Arylation of Chromanones with Arylboronic Acids
Cho, Yang Yil,Jang, Hyu Jeong,Kim, Dong Hwan,Kim, Nam Yong,Kim, Nam-Jung,Kim, Young Min,Lee, Soo Jin,Lee, Yong Sup,Park, Boyoung Y.,Son, Seung Hwan,Yoo, Hyung-Seok
, p. 10012 - 10023 (2019/08/30)
A total of 47 flavanones were expediently synthesized via one-pot β-arylation of chromanones, a class of simple ketones possessing chemically unactivated β sites, with arylboronic acids via tandem palladium(II) catalysis. This reaction provides a novel route to various flavanones, including natural products such as naringenin trimethyl ether, in yields up to 92percent.
Total synthesis of agalloside, isolated from: Aquilaria agallocha, by the 5-O-glycosylation of flavan
Arai, Midori A.,Yamaguchi, Yumi,Ishibashi, Masami
, p. 5025 - 5032 (2017/07/10)
Agalloside (1) is a neural stem cell differentiation activator isolated from Aquilaria agallocha by our group using Hes1 immobilized beads. We conducted the first total synthesis of agalloside (1) via the 5-O-glycosylation of flavan 25 using glycosyl fluoride 20 in the presence of BF3·Et2O. Subsequent oxidation with DDQ to flavanone 2 and deprotection successively provided agalloside (1). This synthetic strategy holds promise for use in the synthesis of 5-O-glycosylated flavonoids. The synthesized agalloside (1) accelerated neural stem cell differentiation, which is a result comparable to that for the naturally occurring compound 1.
Practical synthesis of naringenin
Wang, Qian,Yang, Jian,Zhang, Xiang-Ming,Zhou, Lei,Liao, Xia-Li,Yang, Bo
, p. 455 - 457 (2015/11/03)
Two routes for the synthesis of the flavanone naringenin are described. In the first, 3,5-dimethoxyphenol is converted to 2-hydroxy- 4,6-dimethoxyacetophenone and then by condensation with anisaldehyde to 2′-hydroxy-4,4′,6′-trimethoxychalcone. The chalcone is then cyclised with aqueous hydrochloric acid and demethylated with pyridine hydrochloride to form naringenin in 45% overall yield. The condensation of 2-hydroxy-4,6-dimethoxyacetophenone with anisaldehyde could also directly produce 4′,5,7-trimethoxyflavanone, which was then converted into naringenin in 60% overall yield. In the second route, a single step for the preparation of the chalcone is used in which 1,3,5-trimethoxybenzene is acylated with p-methoxycinnamic acid. Although the synthesis of naringenin is achieved in a lower overall yield of 29%, the process is simpler.
A novel synthesis of naringenin and related flavanones
Cui, Wei,Zhang, Ji,Wang, Qian,Gao, Kai,Zhang, Wei,Yang, Jian
, p. 686 - 689 (2015/02/19)
Efficient methods are reported for the preparation of naringenin (4',5,7-trihydroxyflavanone) which could be easily scaled-up. They have been applied to three other flavanones (6.hydroxyflavanone, 6,4'-dihydroxyflavanone, 6,3',4'-trihydroxyflavanone) suitably.
A practical access to highly enantiomerically pure flavanones by catalytic asymmetric transfer hydrogenation
Lemke, Marie-Kristin,Schwab, Pia,Fischer, Petra,Tischer, Sandra,Witt, Morris,Noehringer, Laurence,Rogachev, Victor,Jaeger, Anne,Kataeva, Olga,Froehlich, Roland,Metz, Peter
supporting information, p. 11651 - 11655 (2013/11/06)
A surprisingly selective, non-enzymatic kinetic resolution of readily available, racemic β-chiral ketones enabled the title process, which was applied to a rapid synthesis of several bioactive flavanones in virtually enantiopure form (see scheme; MOM=methoxymethyl, Ts=p-toluenesulfonyl). Copyright
Regioselective iodination of flavonoids by N-iodosuccinimide under neutral conditions
Lu, Kui,Chu, Jie,Wang, Haomeng,Fu, Xiaoli,Quan, Dewu,Ding, Hongxia,Yao, Qingwei,Yu, Peng
supporting information, p. 6345 - 6348 (2013/11/06)
Regioselective synthesis of C-6 and C-8 monoiodo flavonoids, which are important intermediates for the synthesis of flavonoid natural products and drug molecules, was achieved by iodination of suitably alkylated flavonoids with N-iodosuccinimide (NIS) in DMF. The iodination gives either a C-6 or C-8 iodo flavonoid in high yield, depending on the protection pattern of the C-5 and C-7 OH groups. The mild and neutral conditions render this novel protocol particularly useful for the regioselective iodination of acid-sensitive substrates.
Cytotoxicity against KB and NCI-H187 cell lines of modified flavonoids from Kaempferia parviflora
Yenjai, Chavi,Wanich, Suchana
supporting information; experimental part, p. 2821 - 2823 (2010/08/06)
Flavones 1-4 isolated from Kaempferia parviflora were used for structural modification. Sixteen flavonoid derivatives, including four new derivatives, were synthesized and evaluated for cytotoxicity against KB and NCI-H187 cell lines. Flavanones 2a-4a demonstrated higher cytotoxic activity than the parent compounds. Cytotoxicity against KB cell line of oxime 1c was about 7 times higher than the ellipticine standard. Interestingly, oximes 1c and 2c exhibited highly potent cytotoxicity against NCI-H187 cell line with IC50 values of 0.014 and 0.23 μM, respectively. Oximes 4c and 5c showed strong cytotoxicity against NCI-H187 cell line with IC50 values of 4.04 and 2.32 μM, respectively.
Silica gel supported TaBr5: New catalyst for the facile and rapid cyclization of 2′-aminochalcones to the corresponding 2-aryl-2,3-dihydroquinolin-4(1H)-ones under solvent-free conditions
Ahmed, Naseem,Van Lier, Johan E.
, p. 2725 - 2729 (2007/10/03)
Silica gel supported TaBr5 (5-10 mol %) is a new solid-support catalyst that can be used under solvent-free conditions for the facile and efficient isomerization of 2′-aminochalcones to the corresponding 2-aryl-2,3-dihydroquinolin-4(1H)-ones. The catalyst is easily prepared, stable and employed under environmentally friendly conditions.
(±)-Diinsininone: made nature's way
Selenski, Carolyn,Pettus, Thomas R.R.
, p. 5298 - 5307 (2007/10/03)
We report the synthesis of diinsininone (33), the aglycone of (±)-diinsinin (2). Thereby, we complete the first construction of a proanthocyanidin (PA) type-A compound incorporating a [3.3.1]-bicyclic ketal as its characteristic core. Our strategy utilizes a coupling between a benzopyrilium salt and a flavanone that proves applicable to other PA type-A compounds. During this undertaking, treatment of naringenin (9) with 2-iodoxybenzoic acid (IBX) followed by reductive work-up affords eriodictyol (10). This reactivity mirrors that of catechol hydroxylase (F3H) found in the flavonoid pathway. Other interesting transformations include the formation of flavonoids through an ortho-quinone methide (o-QM) cycloaddition-oxidation sequence and regioselective β-glycosidations of several unprotected flavanones suggesting a likely synthesis of 2 from the aglycone 33.
