Chiral Pseudohomogeneous Catalyst Based on Amphiphilic Carbon Quantum Dots for the Enantioselective Kharasch–Sosnovsky Reaction

Abstract

The term “chiral pseudohomogeneous catalyst (PHC)” denotes a novel concept that characterizes subnanometric particles exhibiting atomic-level chirality. The PHC based on chiral amphiphilic carbon quantum dots possesses distinctive features that combine the strengths of both homogeneous and heterogeneous catalysts, thereby heralding a significant breakthrough in the fields of asymmetric synthesis and medicinal chemistry. To the best of our knowledge, this is the first and the only reported research of a chiral PHC that demonstrates exceptional performance in controlling the enantioselectivity of the Kharasch–Sosnovsky reaction, yielding the corresponding products in high conversion (95%) with a moderate enantiomeric excess (75%). Notably, the chiral information on l-tryptophan can be effectively transferred from the outer shell of the nanosized catalyst, thereby inducing enantioselectivity in C–H activation and subsequent C–O forming events. Additionally, we have investigated the impact of various factors on the allylic oxidation reaction, including the amount, diversity, and hydrophilic/hydrophobic nature of the catalyst, as well as the influence of the solvent, Cu salts, temperature, and the type of alkene and perester, in order to comprehensively explore the reaction conditions. Furthermore, the catalyst can be readily recycled from the reaction medium, making this PHC a promising innovation that can significantly impact practical applications. In summary, this breakthrough can be aptly described as a “Golden Gate” due to its unparalleled potential to open up novel avenues for research and innovation.

Hydrothermal Synthesis of Tartaric Acid Functionalized Amino Acid CQD for Sensing of Hg2+ and Fe3+ Ions in Aqueous Medium

“…CQDs were functionalized with an amino acid, which is the building block of proteins and peptides, which consists of chemical and physical properties with the presence of positive and negative charges with a hydrophobic nature along with the aromatic functional group. [21,22,23] These functional moieties play a key role in molecular interactions. [24] In particular, we have prepared CQDs by hydrothermal methods using L-tryptophan and tartaric acid (coded as CQD-TA-TRYP).…”

“…In this work, we describe the synthesis of promising fluorescent carbon dots by a one‐step hydrothermal method. CQDs were functionalized with an amino acid, which is the building block of proteins and peptides, which consists of chemical and physical properties with the presence of positive and negative charges with a hydrophobic nature along with the aromatic functional group [21,22,23] . These functional moieties play a key role in molecular interactions [24] .…”