1678-20-2Relevant academic research and scientific papers
Stereoselective reduction of flavanones by marine-derived fungi
Birolli, Willian G.,Nitschke, Marcia,Porto, André Luiz M.,Santos, Darlisson de A.,de Matos, Iara L.
, (2021/08/13)
Biotransformation is an alternative with great potential to modify the structures of natural and synthetic flavonoids. Therefore, the bioreduction of synthetic halogenated flavanones employing marine-derived fungi was described, aiming the synthesis of flavan-4-ols 3a-g with high enantiomeric excesses (ee) of both cis- and trans-diastereoisomers (up to >99% ee). Ten strains were screened for reduction of flavanone 2a in liquid medium and in phosphate buffer solution. The most selective strains Cladosporium sp. CBMAI 1237 and Acremonium sp. CBMAI1676 were employed for reduction of flavanones 2a-g. The fungus Cladosporium sp. CBMAI 1237 presented yields of 72–87% with 0–64% ee cis and 0–30% ee trans with diastereoisomeric ratio (dr) from 52:48 to 64:36 (cis:trans). Whereas Acremonium sp. CBMAI 1676 resulted in 31% yield with 77–99% ee of the cis and 95–99% ee of the trans-diastereoisomers 3a-g with a dr from 54:46 to 96:4 (cis:trans). To our knowledge, this is the first report of the brominated flavon-4-ols 3e and 3f. The use of fungi, with emphasis for these marine-derived strains, is an interesting approach for enantioselective reduction of halogenated flavanones. Therefore, this strategy can be explored to obtain enantioenriched compounds with biological activities.
A Borane-Catalyzed Metal-Free Hydrosilylation of Chromones and Flavones
Ren, Xiaoyu,Han, Caifang,Feng, Xiangqing,Du, Haifeng
, p. 2421 - 2424 (2017/11/04)
A Piers-type hydrosilylation of chromones and flavones has been successfully realized for the first time using 0.1 mol % of borane catalyst generated in situ by hydroboration of pentafluorostyrene with HB(C 6 F 5) 2 to afford a variety of chromanones and flavanones in 60-99% yields. An attempt for the asymmetric transformation with chiral diyne and HB(C 6 F 5) 2 gave chromanones and flavanones in high yields with up to 32% ee.
Synthesis, crystal structure and antitumour activity evaluation of 1H-thieno[2,3-c]chromen-4(2H)-one derivatives
Yu, Huchang,Li, Yan,Feng, Zhiyuan,Jiang, Hongwu,Zhao, Yinglan,Luo, Youfu,Huang, Wencai,Li, Zicheng
, p. 36 - 41 (2017/02/15)
A series of 1H-thieno[2,3-c]chromen-4(2H)-one derivatives were synthesised through Knoevenagel condensation of substituted flavanones with thiazolidine-2,4-dione in ethanol in the presence of piperidine. The mechanism of the reaction was proposed. All synthesised compounds were characterised by IR, 1H NMR, 13C NMR, HRMS, and elemental analysis. The structure of 2-(3-chlorophenyl)-1H-thieno[2,3-c]chromen-4(2H)-one was confirmed by a single crystal X-ray diffraction analysis. A preliminary antitumour screening showed that 2-(2-fluorophenyl)-1H-thieno [2,3-c]chromen-4(2H)-one had moderate to good activity against A549, BGC-823, HCT116 and MDA-MB-453 cancer cell lines, and 2-(3,4-dimethoxyphenyl)-1H-thieno[2,3-c]chromen-4(2H)-one displayed similar activity against these four kinds of cancer cells compared with the reference drug.
Rhodium/chiral diene-catalyzed asymmetric 1,4-addition of arylboronic acids to chromones: A highly enantioselective pathway for accessing chiral flavanones
He, Qijie,Wang, Jun,So, Chau Ming,Hayashi, Tamio,Bian, Zhaoxiang
, p. 540 - 543 (2015/05/05)
Chromone has been noted to be one of the most challenging substrates in the asymmetric 1,4-addi-tion of α,β-unsaturated carbonyl compounds. By employing the rhodium complex associated with a chiral diene ligand, (R,R)-Ph-bod, the 1,4-addition of a variety of aryl-boronic acids was realized to give high yields of the corresponding flavanones with excellent enantioselectivities (≥97% ee, 99% ee for most substrates). Ring-opening side products, which would lead to erosion of product enantioselectivity, were not observed under the stated reaction conditions.
Impact of mono- and disubstitution on the colorimetric dynamic covalent switching chalcone/flavanone scaffold
Muller, Brian M.,Mai, Jesse,Yocum, Reid A.,Adler, Marc J.
supporting information, p. 5108 - 5114 (2014/07/08)
The effect of aryl substitution on various aspects of the interconversion of ortho-hydroxychalcones and flavanones has been studied using multiple spectroscopic techniques. Derivatization of the core scaffold predictably alters the midpoint pH of this equilibration process suggesting its viability for application as a functional colorimetric molecular switch.
Synthetic approach to flavanones and flavones via ligand-free palladium(ii)-catalyzed conjugate addition of arylboronic acids to chromones
Kim, Donghee,Ham, Kyungrok,Hong, Sungwoo
experimental part, p. 7305 - 7312 (2012/09/22)
The remarkable catalytic effects of Fe(OTf)3 in the context of the Pd(ii)-catalyzed conjugate addition of arylboronic acids to chromones were observed to yield a variety of flavanones under mild conditions. The addition of catalytic amounts of DDQ and KNO2 to the reactions exclusively yielded flavone analogs. The reaction scope for the transformation was fairly broad, affording good yields of a wide range of flavanones and flavones, which are privileged structures in many biologically active compounds.
