1840-02-4Relevant academic research and scientific papers
Synthesis of Flavanone and Quinazolinone Derivatives from the Ruthenium-Catalyzed Deaminative Coupling Reaction of 2′-Hydroxyaryl Ketones and 2-Aminobenzamides with Simple Amines
Gnyawali, Krishna,Kirinde Arachchige, Pandula T.,Yi, Chae S.
supporting information, p. 218 - 222 (2022/01/15)
The cationic Ru–H complex [(C6H6)(PCy3)(CO)RuH]+BF4– (1) with 3,4,5,6-tetrachloro-1,2-benzoquinone (L1) was found to be a highly effective catalyst for the deaminative coupling reaction of 2′-hydroxyaryl ketones with simple amines to form 3-substituted flavanone products. The analogous deaminative coupling reaction of 2-aminobenzamides with branched amines directly formed 3,3-disubstituted quinazolinone products. The catalytic method efficiently installs synthetically useful flavanone and quinazolinone core structures without employing any reactive reagents.
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.
B regioselective and chemoselective biotransformation of 2′-hydroxychalcone derivatives by marine-derived fungi
Nitschke, Marcia,Porto, André Luiz Meleiro,de Matos, Iara Lisboa
, (2021/08/06)
Eight fungal strains (Penicillium raistrickii CBMAI 931, Cladosporium sp. CBMAI 1237, Aspergillus sydowii CBMAI 935, Penicillium oxalicum CBMAI 1996, Penicillium citrinum CBMAI 1186, Mucor racemosus CBMAI 847, Westerdykella sp. CBMAI 1679, and Aspergillus sclerotiorum CBMAI 849) mediated the biotransformation of the 2′-hydroxychalcone 1a. The main products obtained were from hydrogenation, hydroxylation, and cyclization reactions. Penicillium raistrickii CBMAI 931 catalyzed the chemoselective reduction of 1a to produce 2′-hydroxydihydrochalcone 2a (72%) in 7 days of incubation in phosphate buffer (pH 7). Aspergillus sydowii CBMAI 935 promoted the hydroxylation of 1a to yield 2′,4-dihydroxy-dihydrochalcone 5a (c = 42%) in 7 days of incubation in phosphate buffer (pH 8). The reaction using P. citrinum CBMAI 1186 and M. racemosus CBMAI 847 presented main cyclization products in phosphate buffer (pH 8), but the reactions with these fungi did not present enantioselectivity. Marine-derived fungi were effective and versatile biocatalysts for biotransformation of the 2′-hydroxychalcones yielding different products according to the conditions and microorganism used.
Divergent synthesis of flavones and flavanones from 2′-hydroxydihydrochalconesviapalladium(ii)-catalyzed oxidative cyclization
Son, Seung Hwan,Cho, Yang Yil,Yoo, Hyung-Seok,Lee, Soo Jin,Kim, Young Min,Jang, Hyu Jeong,Kim, Dong Hwan,Shin, Jeong-Won,Kim, Nam-Jung
, p. 14000 - 14006 (2021/04/22)
Divergent and versatile synthetic routes to flavones and flavanonesviaefficient Pd(ii) catalysis are disclosed. These Pd(ii) catalyses expediently provide a variety of flavones and flavanones from 2′-hydroxydihydrochalcones as common intermediates, depending on oxidants and additives,viadiscriminate oxidative cyclization sequences involving dehydrogenation, respectively, in a highly atom-economic manner.
Organocatalytic Approach for Assembling Flavanones via a Cascade 1,4-Conjugate Addition/oxa-Michael Addition between Propargylamines with Water
He, Xinwei,He, Xinwei,Xie, Mengqing,Li, Ruxue,Choy, Pui Ying,Tang, Qiang,Shang, Yongjia,Kwong, Fuk Yee
, p. 4306 - 4310 (2020/06/05)
A DBU-catalyzed one-pot cascade reaction of propargylamines and water for the synthesis of flavanones has been developed. This process proceeds via a sequence of 1,4-conjugate addition of water to alkynyl o-quinone methide (o-AQM), followed by the alkyne-allene isomerization and subsequent intramolecular oxa-Michael addition. This strategy provides a convenient method for accessing a broad range of flavanones in good to excellent yields with good functional-group tolerance, in particular, the reactive halo functional groups.
Enzyme-assisted cyclization of chalcones to flavanones
Alonso, Mariana Macías,Boluda, Carlos José,Barajas, Gabriela Díaz,Sánchez, Nallely Caldera,Córdova-Guerrero, Iván,Marrero, Joaquín González
, p. 926 - 931 (2020/12/23)
Enzyme catalyzed synthesis is an eco-friendly technique in organic synthesis, having several benefits over conventional methods. In the present work, we describe a simple process of laccase and chloroperoxidase assisted cyclization of chalcones, leading to the formation of flavanones. The reaction proceeds in a mixture of phosphate buffer and ethanol, under oxygen atmosphere at room temperature, yielding the corresponding flavanone in good to moderate yield. The relative configuration of the products at C2 is tentatively assigned as S*-flavanone based on the coupling constants with the methylenic protons H3α,β. In comparison to the chemical methods, we describe a process which can be achieved efficiently under mild conditions using oxygen as oxidant.
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.
Palladium-Catalyzed [3+3] Annulation of Vinyl Chromium(0) Carbene Complexes through Carbene Migratory Insertion/Tsuji–Trost Reaction
Wang, Kang,Ping, Yifan,Chang, Taiwei,Wang, Jianbo
, p. 13140 - 13144 (2017/10/11)
Vinyl chromium(0) Fischer carbene complexes were employed as the source of π-allylic palladium species for catalytic [3+3] annulation under palladium catalysis. Mechanistically, this transformation is proposed to involve carbene migratory insertion and intramolecular Tsuji–Trost reaction as the key steps. Substituted six-membered heterocyclic flavonones and quinolines are obtained, depending on the nucleophilic functional group on the coupling partners.
An efficient synthesis of flavanones and their docking studies with aldose reductase
Kondhare,Gyananath,Tamboli, Yasinalli,Kumbhar, Santosh S.,Choudhari, Prafulla B.,Bhatia, Manish S.,Zubaidha
, p. 987 - 998 (2017/04/14)
A series of flavanone derivatives have been synthesized from 2-hydroxy acetophenone and benzaldehyde using fused calcium chloride in good to moderate yields, and their in vitro aldose reductase inhibitory activity has been tested on aldose reductase purified enzyme from Bovine lens. Most of the synthesized compounds exhibited potent aldose reductase inhibitory activity, and the obtained results are supported by the docking studies. Among the tested derivatives, 2, 3, 4-methoxy derivative 19 (IC50 5.88 ± 0.03 μM) exhibited the highest inhibitory activity whereas 2-methoxy derivative 12 showed the lowest, and the remaining compounds exhibited moderate activity with IC50 in the range of 6.09–7.89 μM. The spatial configuration of the most active derivative 19 was compared with pharmacophore requirements of the aldose reductase inhibitor site using a molecular modeling system.
Nanosilica-supported dual acidic ionic liquid as a heterogeneous and reusable catalyst for the synthesis of flavanones under solvent-free conditions
Rostamizadeh, Shahnaz,Zekri, Negar,Tahershamsi, Leili
, p. 526 - 530 (2016/02/16)
[Figure not available: see fulltext.] A nanosilica-supported dual acidic ionic liquid on the basis of 1-methyl-3-(4-sulfobutyl)imidazolium hydrogen sulfate was synthesized and used as an efficient, green, non-corrosive, non-toxic, heterogeneous, and reusable catalyst for the synthesis of some new and known substituted flavanones. The synthesis was done by the condensation of 2'-hydroxyacetophenone with different aldehydes and the subsequent cyclization of the resulting 2'-hydroxychalcone in the presence of the catalyst. High yields of the products, short reaction times, and solvent-free conditions characterize this new method.
