In this paper, a novel approach to regioselective α- or γ-hydroarylation of 3-allylchromones with electron-rich arenes has been presented. Results of this study indicated that the regioselectivity was dependent on the substituent at the γ-position of the allyl group. Hydrogen or alkyl substitution favored α-hydroarylation, whereas aryl substitution favored γ-hydroarylation. This methodology provides an efficient means to achieve the α- or γ-selective hydroarylation of 3-allylchromones. Application of α-hydroarylation to perform Pd-catalyzed one-pot sequential α-hydroarylation and π-chelation-assisted olefination has also been reported.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1039/c9ob01147a | DOI Listing |
Metab Eng
January 2025
Biochemistry, Molecular, Cellular, and Developmental Graduate Group, University of California, Davis, Davis, CA, 95616, USA; Department of Chemistry, University of California, Davis, Davis, CA, 95616, USA. Electronic address:
D-allose is a rare monosaccharide, found naturally in low abundances. Due to its low-calorie profile and similar taste to sucrose, D-allose has the potential to become an ideal sugar substitute. D-allose also displays unique properties and health benefits that can be applied to various fields, including food and medicine.
View Article and Find Full Text PDFChemistry
January 2025
The University of Electro-Communications: Denki Tsushin Daigaku, Department of Engineering Science, JAPAN.
(6,5)-enriched single-walled carbon nanotubes (SWCNTs) were reductively arylated using sodium naphthalenide and monosubstituted and disubstituted iodobenzene derivatives to control their photoluminescence (PL) properties. In the reactions with substituted iodobenzenes, the degree of functionalization was influenced by the substituents on the aryl groups depending on their position, which allowed us to realize control of the PL intensity. The substituents at the 2-position and methyl groups at the 3,5-positions of the phenyl group respectively increased the E11** PL and E11* PL selectivity at ~1230 and ~1100 nm.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, United States.
Under most conditions, 2,4-dihalopyrimidines undergo substitution reactions at C4. Here we report that Pd(II) precatalysts supported by bulky -heterocyclic carbene ligands uniquely effect C2-selective cross-coupling of 2,4-dichloropyrimidine with thiols. The regioselectivity of this reaction stands in stark contrast to ∼1500 previously reported Pd-catalyzed cross-couplings that favor C4 in the absence of other substituents on the pyrimidine ring.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
College of Food Science, Southwest University, Tiansheng Road 2, Chongqing, 400715, PR China. Electronic address:
In this study, type-3 resistant starch (RS) with enhanced thermal stability and excellent short-chain fatty acid (SCFA) production was obtained through the butyrylation and subsequent recrystallization at 4 °C of high-amylose maize starch (HAMS). We comprehensively examined and contrasted the structural attributes and in vitro human fecal fermentation behavior of butyrylated RS (BRS) with varying degrees of substitution. Fourier-transform infrared analysis validated the successful integration of carbonyl groups into the starch matrix.
View Article and Find Full Text PDFHuman epidermal growth factor receptor 2 (HER2, also known as ERBB2) signaling promotes cell growth and differentiation, and is overexpressed in several tumor types, including breast, gastric and colorectal cancer. HER2-targeted therapies have shown clinical activity against these tumor types, resulting in regulatory approvals. However, the efficacy of HER2 therapies in tumors with HER2 mutations has not been widely investigated.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!