Journal of Organic Chemistry最新文献

A modular total synthesis of A201E and its analogues is modeled after the previously reported biosynthetic pathway. The challenging task of obtaining 1,2-cis-furanoside, a vital core structure of A201E and its analogues, was accomplished through the strategic use of remote 2-quinolinecarbonyl-assisted glycosylation. From this pivotal 1,2-cis-furanoside moiety, we successfully completed the total synthesis of A201E and its analogues. Guided by the principles of medicinal chemistry, we evaluated the antimicrobial activities of A201A/E and its analogues. A comprehensive assessment of their antimicrobial activities has illuminated the structure–activity relationship of A201A/E and its analogues. The synthetic strategy we report herein will guide the creation of additional analogues, potentially elucidating the mode of action and addressing a critical area of unmet medical need.

We report self-assembling water-soluble nucleobase monomers with a broad scope for biomaterial and protein bioconjugation applications. These nucleobase monomers are adorned with nature-inspired triple G-C-T nucleobases featuring three recognition sites: DDA (G mimic), DAA (C mimic), and ADA (T mimic). Using readily accessible starting materials, these monomers can be synthesized in excellent yields, making them good choices for diverse applications. Their unique structural features, coupled with their water solubility, may offer exciting opportunities for the creation of new biomaterials.

The first metal- and base-free construction of diastereomeric hydrobenzofurans and hydronaphthofurans, which were capable of further transformations to achieve natural product frameworks, was achieved by the intramolecular oxidized dearomatization of phenol or naphthol derivatives via the promotion of iodine reagents. Enantioselective products were obtained through chiral substrates or iodine catalysts. This step-economical protocol built multiple chiral centers with extensive tolerance of various substrates, which resulted in a potential molecular library for developing functional polycyclic scaffolds.

Herein, we report that binuclear copper complexes used as dehydrogenative catalysts, combined with oxygen as an oxidant and 2,2,6,6-tetramethylpiperidinyl-1-oxide (TEMPO) as an additive, are capable of effectively catalyzing the successive dehydrogenation of aromatic propanols to produce α,β-unsaturated aldehydes. This method has the advantages of high efficiency, simple operation, and oxygen as an oxidant. The reaction mechanism of continuous dehydrogenation of aromatic propanols was investigated by in situ infrared spectroscopy and control experiments. The dehydrogenation process suggested that phenylpropanol was first oxidized to arylpropanals and then underwent α,β-selective dehydrogenation of the carbonyl group to yield α,β-unsaturated aldehydes. This protocol provides insights into the design and synthesis of efficient catalysts for the preparation of α,β-unsaturated aldehydes by continuous dehydrogenation of aromatic propanols.

The structural and photophysical properties in the halogen bonding environment were thoroughly studied for a newly synthesized series of fluorescent dyes and their model derivatives. The analysis revealed that the ground-state interactions among both series are likewise. The fluorescent dyes have push–pull topology, and there is a low-lying charge-transfer (CT) excited state in their electronic structure. In order to study the effect of intermolecular interactions on the photophysical parameters of the CT excited state, a palette of solvents was used (C₆F₆, C₆F₅Cl, C₆F₅Br, and C₆F₅I). Our studies revealed that the weak halogen bonding between the perfluorohaloarene solvent and the heterocyclic core of the dyes enhances the CT in their excited states. The results also demonstrated that the position of the heterocyclic nitrogen atom in the acceptor core simultaneously controls the directionality of the intermolecular interaction and influences both the emission wavelength and the fluorescence quantum yield. Experimental data were further supported by the results of quantum-chemical calculations. Overall, the study establishes a direct link between the topology of a moiety prone to specific intermolecular interactions and the photophysical properties of fluorescent probes.