A Combination of Furfuryl Cation Induced Three-Component Reactions and Photocatalyst-Free Photoisomerization To Construct Complex Triazoles

A novel stereospecific synthesis of (<i>Z</i>)- and (<i>E</i>)-β-triazole-acrylates by the combined use of a multicomponent reaction and photocatalyst-free photoisomerization is presented. The former can be regarded as a furfuryl cation induced formal [3 + 2]-cycloaddition/ring-opening/esterification domino sequence, which provides fast access to a variety of structurally diverse (<i>Z</i>)-β-triazole-acrylates. The products were further photoisomerized to (<i>E</i>)-configuration by UV irradiation. This efficient strategy was utilized in the concise synthesis of histone deacetylase inhibtor NSC746457 in high yield

Europium-Functionalized Graphitic Carbon Nitride for Efficient Chemiluminescence Detection of Singlet Oxygen

Enhancing the sensitivity and selectivity of chemiluminescence (CL) sensors for detecting chemical species in complex samples poses a significant challenge in nanoparticle surface engineering. Graphitic carbon nitride (CN) shows promise but suffers from weak CL intensity and unknown luminescence mechanisms. In this study, we propose a nitrogen defect strategy to enhance the CL efficiency of europium-functionalized graphitic carbon nitride (Eu-CNNPs). By controlling the dosage of the europium modification, we can adjust the nitrogen defect content to reduce the energy gap and improve the CL performance. Remarkably, Eu-CNNPs with rich nitrogen defects exhibit strong chemiluminescence emission specifically for singlet oxygen (1O2) without responding to other reactive oxygen species (ROS). Building upon this finding, we developed a direct, selective, and sensitive CL sensing platform for 1O2 in PM2.5 and monitored 1O2 production in photosensitizers without interference from metal ions. Through extensive experiments, we attribute the 1O2-driven CL response to the presence of abundant nitrogen defects in the CN material, accelerating electron transfer and yielding a high generation of 1O2. Furthermore, chemiluminescence resonance energy transfer (CRET) between (1O2)2* (1O2 dimeric aggregate) and Eu-CNNPs contributes to strong CL emission. This work provides insights into enhancing the CL performance of CN and offers new possibilities for advancing the practical analysis of nanomaterials using the intriguing mechanism of nitrogen defects

Conversion of 2‑Furylcarbinols with Alkyl or Aryl Azides to Highly Functionalized 1,2,3-Triazoles via Cascade Formal [3 + 2] Cycloaddition/Ring-Opening

A Lewis acid promoted cascade cycloaddition/ring-opening of 2-furylcarbinols with alkyl or aryl azides is described. The reaction features an initial formal [3 + 2] cycloaddition to form a trisubstitued triazole motif, followed by a ring opening of furan to generate the (<i>E</i>)-configuration of the enone. A wide range of highly functionalized triazoles is expediently and efficiently synthesized in a highly step-economical manner

Conversion of 2‑Furylcarbinols with Alkyl or Aryl Azides to Highly Functionalized 1,2,3-Triazoles via Cascade Formal [3 + 2] Cycloaddition/Ring-Opening

A Lewis acid promoted cascade cycloaddition/ring-opening of 2-furylcarbinols with alkyl or aryl azides is described. The reaction features an initial formal [3 + 2] cycloaddition to form a trisubstitued triazole motif, followed by a ring opening of furan to generate the (<i>E</i>)-configuration of the enone. A wide range of highly functionalized triazoles is expediently and efficiently synthesized in a highly step-economical manner