Visible‐Light‐Induced Direct C−H Amination of Quinoxalin‐2(1H)‐ones

Abstract

A visible‐light‐induced direct C(sp2)−H amination of quinoxalin‐2(1H)‐ones toward the synthesis of substituted 3‐aminoquinoxalin‐2(1H)‐ones with TMSN3 has been firstly developed. This transformation achieved C(sp2)−H/N−H coupling in the absence of external ligand and oxidant. Notably, this methodology features mild reaction conditions, broad substrate scope and operational simplicity.

Iron‐Catalyzed Direct C3−H Trifluoromethylthiolation of Quinoxalin‐2(1H)‐ones

“…On the basis of the above experimental results and literature reports, [13,19e,25] we proposed a plausible mechanism for this Fe‐catalyzed trifluoromethylthiolation of quinoxalin‐2(1 H )‐ones with AgSCF 3 (Scheme 4). First, AgSCF 3 is oxidized by K 2 S 2 O 8 to generate SCF 3 radical [13] .…”

“…Despite these elegant progresses, the synthesis of quinoxalin‐2(1 H )‐ones bearing a trifluoromethylthio group (SCF 3 ) at the C3 position has not been reported. With our continuous studies in C−H functionalization and fluorine chemistry, [13g,19e,24] herein, we report a Fe‐catalyzed direct C3−H trifluoromethylthiolation of quinoxalin‐2(1 H )‐ones by utilizing earth‐abundant iron salt as catalyst, and AgSCF 3 as the trifluoromethylthiolating reagent (Scheme 1C).…”

“…Then, the SO 4 ⋅ − might be converted into SO 4 2− in the presence of Ag(I) [25a–b] . Meanwhile, 1 a is more likely to be protonated in the presence of trifluoroacetic acid to afford intermediate A [19e] . Then, SCF 3 radical attacks C3‐site of intermediate A to produce the activated species B , which is further transformed into nitrogen‐centered radical intermediate C .…”

Introduction to Artificial Intelligence and Robotics

“…In addition to GPT-4, the open-sourced LLM, Llama2 [26], and its variants have emerged for various applications, especially for vision tasks. For instance, Mini GPT-4 [33] utilizes Vicuna [5] and a frozen vision encoder to learn a multi-modality alignment, enabling the generation of detailed image descriptions, website creation from sketches, and other complex reasoning tasks; LLaVA [16] leverages visual instruction tuning with language-only GPT-4 and a frozen vision encoder, enabling advanced multi-modal understanding and interaction capabilities. Despite these attempts, the SGG capability of LLMs still needs to be explored.…”

Self‐Calibrated Flexible Holographic Curvature Sensor

“…[18,19] In all these cases, the measurement involves DOI: 10.1002/admt.202301851 converting the optical signal into an electrical one, using photodetectors or optical spectrum analyzers, which require calibration, and readout terminals to convey the data to the user. [17,20,21] Holographic metasurfaces (HMSs) offer unique advantages in optical imaging applications, including multi-color and three-dimensional displays, [22] virtual reality, [23] augmented reality, [24] and multi-information encoding and display. [25,26] These advantages stem from their ability to manipulate the properties of light, such as phase, [27] amplitude, [28] and polarization.…”