Spectrochim Acta A Mol Biomol Spectrosc
March 2025
Phenylthiazide compounds are frequently utilized to construct electron donor-acceptor (D-A) dyes, exhibiting excellent fluorescence and colorimetric analysis performance due to their electron-rich properties. Three D-A type compounds 5a-c, featuring intramolecular charge transfer (ICT) characteristics, were designed and synthesized using phenothiazine as the donor and various aryl-substituted imidazoles as acceptors for the detection of hypochlorite. Additionally, the ICT properties of the compounds can be fine-tuned by introducing various substituents to achieve a more sensitive optical response to HClO/ClO.
View Article and Find Full Text PDFA photoinduced vitamin-B-catalyzed -C-H bromination/chlorination of phenol derivatives was established using a nitrile directing template and -bromosuccinimide (NBS)/-chlorosuccinimide (NCS) as halogenated reagents, and a series of -bromination/chlorination products were obtained in yields of 51 to 80%. This strategy overcame the selectivity problem of phenols, which have difficulty obtaining -products through conventional electrophilic reactions. Furthermore, natural product resveratrol and an intermediate of the γ-secretase inhibitor were successfully synthesized, which demonstrates the practicability of this method.
View Article and Find Full Text PDFA mild strategy for Co(III)-catalyzed C(sp)-H cyanation of indoles was developed by using NCBLD as an electrophilic cyanation reagent and 1-butyl-3-acetylimidazole ditrifluoromethylsulfonimide ([BAIM]NTf) as an environmentally friendly and recyclable solvent, and a series of 2-cyano products were obtained at room temperature. Adopting this strategy, the unnatural nucleotide fragment precursor of Remdesivir, which was a drug for COVID-19, was synthesized through cyano transformation, further proving the practicability of this cyanation method.
View Article and Find Full Text PDFA protocol for metal and oxidant free photoredox catalyzed trifluoromethylation of 2-indazoles was developed by using Eosin Y as the photocatalyst and recoverable ionic liquids as the solvents. A series of trifluoromethylated products were obtained in moderate to good yields in this protocol under mild conditions. The reaction proceeded a free-radical mechanism with a broad substrate range, excellent regioselectivity, and good functional group tolerance.
View Article and Find Full Text PDFA strategy was developed for the visible-light-induced photocatalytic synthesis of dihydrochalcone via the deoxygenation and coupling of benzoic acid derivatives with alkenes using diphenyl sulfide as the O-transfer reagent. Under mild photoredox conditions, a series of dihydrochalcone derivatives were produced in moderate to good yields. A mechanism for the visible-light-induced free-radical coupling was proposed on the basis of the control experiments.
View Article and Find Full Text PDFCultural differences-as well as similarities-have been found in explicit color-emotion associations between Chinese and Western populations. However, implicit associations in a cross-cultural context remain an understudied topic, despite their sensitivity to more implicit knowledge. Moreover, they can be used to study color systems-that is, emotional associations with one color in the context of an opposed one.
View Article and Find Full Text PDFA visible-light-induced photocatalytic strategy for the synthesis of flavonoids has been developed through the deoxygenative/cyclization reaction of salicylic acid derivatives with aryl acetylene using diphenyl sulfide as an O-transfer reagent. Based on the controlled experiments, the mechanism of visible-light-induced free radical coupling cyclization was proposed. The protocol obtained 51 flavonoids in good yields and has been successfully applied to the synthesis of some natural flavones.
View Article and Find Full Text PDFA nickel-catalyzed C-H cyanation reaction of arenes has been developed using 2-cyanoisothiazolidine 1,1-dioxide as an electrophilic cyanation reagent. Many different directing groups can be used in this cyanation to obtain a series of cyanation products with good yields. Adopting this strategy to introduce a cyano group, natural alkaloid menisporphine was successfully synthesized through cyano group conversion that further proved the practicality of this cyanation method.
View Article and Find Full Text PDFA visible light-induced decarboxylative alkylation of heterocyclic aromatics with aliphatic carboxylic acids was developed by using anthocyanins as a photocatalyst under mild conditions. A series of alkylated heterocyclic compounds were obtained in moderate to good yields by using the metal-free decarboxylative coupling reaction under blue light. This strategy uses cheap and readily available carboxylic acids as alkylation reagents with good functional group tolerance and environmental friendliness.
View Article and Find Full Text PDFA visible-light-induced palladium-catalyzed cascade reaction was developed by etherification/C-C coupling cyclization of α-bromoacetophenones with phenols. A series of dibenzo[b,d]oxepin-7(6H)-one derivatives were efficiently synthesized by using this method in good yields. Furthermore, this method was applied to the synthesis of protosappanin A.
View Article and Find Full Text PDFA visible-light-induced decarboxylation coupling/intramolecular cyclization is reported. The one-pot synthesis system provides mild, efficient, and atom economical access to the synthesis of 4-aryl-2-quinolinone derivatives. It is notable that the necessary oxidant in the traditional decarboxylation coupling is replaced by the visible-light irradiation in this paper.
View Article and Find Full Text PDFA novel synthetic protocol for the construction of eight-membered heterocycles by intramolecular palladium-catalyzed ortho C-H activation/C-C cyclization was proposed. With protosappanin A as the lead compound, 25 derivatives of 8-azaprotosappanin A were prepared in good yields by this protocol. Besides, a plausible reaction mechanism of the intramolecular cyclization was proposed.
View Article and Find Full Text PDFA total synthesis method for protosappanin A, which is a complex natural product with many biological activities, was developed with 6 linear steps. Dibenzo[b,d]oxepinones as the key intermediates of the synthetic route were prepared by a palladium-catalyzed ortho C-H activation/C-C cyclization under microwave irradiation. 25 derivatives of protosappanin A were obtained.
View Article and Find Full Text PDFNucleic Acids Res
January 2014
Non-B DNA structures are abundant in the genome and are often associated with critical biological processes, including gene regulation, chromosome rearrangement and genome stabilization. In particular, G-quadruplex (G4) may affect alternative splicing based on its ability to impede the activity of RNA polymerase II. However, the specific role of non-B DNA structures in splicing regulation still awaits investigation.
View Article and Find Full Text PDFA new bis(β-diketonate), 1,3-bis(4,4,4-trifluoro-1,3-dioxobutyl)phenyl (BTP), which contains a trifluorinated alkyl group, has been prepared for the synthesis of two series of dinuclear lanthanide complexes with the general formula Ln2(BTP)3L2 [Ln(3+) = Eu(3+), L = DME(1), bpy(2), and phen(3); Ln(3+) = Sm(3+), L = DME(4), bpy(5), and phen(6); DME = ethylene glycol dimethyl ether, bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline]. The crystal structure of the free ligand has been determined and shows a twisted arrangement of the two binding sites around the 1,3-phenylene spacer. X-ray crystallographic analysis reveals that complexes 1, 2, 4, and 5 are triple-stranded dinuclear structures formed by three bis-bidentate ligands with two lanthanide ions.
View Article and Find Full Text PDFThe title compound, C(15)H(13)NO(2), was prepared through a palladium-catalysed Suzuki-Miyaura coupling reaction. The dihedral angle between the biphenyl rings is 40.96 (6)°.
View Article and Find Full Text PDFThe title compound, C(14)H(13)NO(4), was prepared through a palladium-catalysed Suzuki-Miyaura coupling reaction. The asymmetric unit comprises two mol-ecules related by pseudo-inversion symmetry. The dihedral angles between the benzene rings in the two mol-ecules are 44.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
January 2012
The title compound, C(13)H(10)N(4)O(2)S, was prepared through a cyclization reaction of 1,10-phenanthroline-5,6-dione and thio-urea. The dihedral angle between the pyridine rings is 8.22 (2)°.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
January 2012
The title compound, C(17)H(16)O(5), was prepared through a cyclization reaction of 2-(3',4',5-trimeth-oxy-biphenyl-2-yl-oxy)acetyl chloride. The two benzene rings form a dihedral angle of 34.55 (5)°.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
November 2011
The title compound, C(14)H(10)F(3)NO(3), was prepared by a palladium-catalysed Suzuki-Miyaura coupling reaction. The dihedral angle between the nitro group and its parent benzene ring is 66.85 (19)° while the dihedral angle between the two benzene rings is 49.
View Article and Find Full Text PDFBackground: Divergence of transcription factor binding sites is considered to be an important source of regulatory evolution. The associations between transcription factor binding sites and phenotypic diversity have been investigated in many model organisms. However, the understanding of other factors that contribute to it is still limited.
View Article and Find Full Text PDFThe title compound, C(9)H(9)NO(6)S, was prepared by the reaction of methanol and thionyl chloride with 4-methyl-sulfonyl-2-nitro-benzoic acid under mild conditions. The dihedral angle between the nitro group and benzene ring is 21.33 (19)° and that between the carboxyl-ate group and the benzene ring is 72.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
February 2010
In the mol-ecular structure of the title compound, C(11)H(15)N(3)O(5)S, the amide group is nearly perpendicular to the pyridine ring, making a dihedral angle of 86.30 (13)°. The terminal ethyl group is disordered over two sites of equal occupancy.
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