Search

ConspectusAsymmetric electrophilic reactions provide an ideal method for the construction of chiral molecules by incorporating one or more functional groups into the parent substrates under mild conditions. However, due to the issues of the reactivities of electrophilic species and the possible racemization of chiral intermediates as well as the restriction of the chiral scaffolds of chiral catalysts, many limitations remain in this field, such as the narrow scopes of substrates and electrophiles as well as the limited types of nucleophiles and reactions. To overcome the limitations in the synthesis of diversified chiral molecules, we developed a series of indane-based chiral amino aryl chalcogenide catalysts. These catalysts are easily prepared based on the privileged chiral indane scaffold. They can provide an appropriate H-bonding effect by varying the amino protecting groups as well as offer a proper Lewis basicity and steric hindrance by adjusting different substituents on the aryl chalcogenide motifs. These features allow for them to meet the requirements of reactivity and the chiral environment of the reactions. Notably, they have been successfully applied to various asymmetric electrophilic reactions of alkenes, alkynes, and arenes, expanding the field of electrophilic reactions.Using these catalysts, we realized the enantioselective CF

Organoselenium catalysis has attracted increasing interest in recent years. This Cluster highlights recent key advances in this area regarding the functionalization of alkenes, alkynes, and arenes by electrophilic selenium catalysis, selenonium salt catalysis, selenium-based chalcogen-bonding catalysis, and Lewis basic selenium catalysis. These achievements might inspire and help future research.1 Introduction2 Electrophilic Selenium Catalysis3 Selenonium Salt Catalysis4 Selenium-Based Chalcogen-Bond Catalysis5 Lewis Basic Selenide Catalysis6 Conclusion

Selenium catalysis has become an exciting area in organic synthesis. In various selenium-catalyzed reactions, different substrates have been utilized. However, alkynes as substrates have received m...

An unprecedented approach for efficient synthesis of functionalized allylic gem-difluorides via catalytic fluorinative Meyer-Schuster-like rearrangement is disclosed. This transformation proceeded with readily accessible propargylic fluorides, and low-cost B-F reagents and electrophilic reagents by sulfide catalysis. A series of iodinated, brominated, and trifluoromethylthiolated allylic gem-difluorides that were difficult to access by other methods were facilely produced with a wide range of functional groups. Importantly, the obtained iodinated products could be incorporated into different drugs and natural products, and could be expediently converted into many other valuable gem-difluoroalkyl molecules as well. Mechanistic studies revealed that this reaction went through a regioselective fluorination of alkynes followed by a formal 1,3-fluorine migration under the assistance of the B-F reagents to give the desired products.

An efficient route for the synthesis of saturated thiocyano-containing azaheterocycles by selenide-catalyzed regio- and stereoselective thiocyanoaminocyclization of alkenes is disclosed. The desired products were obtained in moderate to high yields under mild conditions. The generality of this method was elucidated by its efficient application in thiocyano oxycyclization of alkenes.

An efficient approach for the organoselenium-catalyzed aza-Wacker reaction of olefinic hydrazones and an oxime to form isoquinolinium imides and an isoquinoline N-oxide is developed. This transformation involves a direct intramolecular C–H amination using hydrazones and an oxime as imine-type nitrogen sources. This work not only provides a new approach for the construction of isoquinoline derivatives, but also expands the scope of nitrogen sources in electrophilic selenium catalysis.

Unprecedented selenium-catalyzed propargylic oxidation of alkynes is disclosed. Various propargylphosphonates and 3-alkynoates were efficiently converted to valuable ynones via unusual C–C triple bond migration and deselenenylation at a vinyl carbon. By the strategies of tautomerization of enamine intermediate and SN2 displacement, similar conditions were effective for the oxidative difunctionalization of ynamides to afford multisubstituted oxazoles with high regioselectivity. Mechanistic studies revealed these detailed processes.

An acid/DEAD system for efficient oxidative cleavage of S–S and Se–Se bonds to generate chalcogenium ions has been developed. These ions could be captured by nucleophile-tethered alkenes and nucleophilic aryl reagents such as arylboronic acids and arenes to afford diverse chalcogenides. Mechanistic studies revealed that an N-sulfenylhydrazine intermediate was involved in the transformations.

An efficient approach for organoselenium-catalyzed regioselective C-H pyridination of 1,3-dienes to form pyridinium salts has been developed. This method was also successfully applied to direct C-H pyridination of alkenes. Fluoropyridinium reagents, or initially loaded pyridine derivatives, acted as pyridine sources in the pyridination reactions. The obtained pyridinium salts could be further converted under different conditions. This work is the first example of catalytic C-2 direct C-H functionalization of 1,3-dienes and the first case of organoselenium-catalyzed C-H pyridination.

Recent advances in Nanomedicine provide promising disease treatment through improved drug delivery efficiency, but clinical applications have encountered difficulties, largely due to the majority of injected nanoparticle is sequestered in liver. In contrast, liver cells seem to be a perfect target for nanoparticles. Here we generated a new formula of liposome encapsulated Nano-MitoPBN as a liver mitochondrial-targeting free radical scavenger. We found that Nano-MitoPBN mainly accumulated in hepatocytes and scavenged hepatic mitochondrial superoxide/hydrogen peroxide generated from mono-electron leak of electron transport chain (ETC) complex I and III. Due to micro-compartmentalization, Nano-MitoPBN increased mitochondrial state 3 respiratory rate and respiratory control ratio (RCR), resulting in decreased NADH:NAD+ ratio, improved mitochondrial oxidative energy coupling and ATP synthesis, thus alleviating ROS-induced mitochondrial dysfunction. The functional mitochondria promoted the substrate oxidation by the liver, resulting in increased glycolysis and TCA cycle, which directly speeds glucose decomposition, thus decreasing the peripheral blood glucose level and improving the impaired glucose tolerance in diabetic animals. Our study suggests the potential of liver mitochondrial targeting antioxidative nanomedicines for diabetes mellitus.

Antimicrobial peptides are components of the innate immune systems in animals and plants as natural defense against pathogens. Critical issues like manufacturing costs have to be addressed before mass production of these peptides for agriculture or community sterilizations. Here, we report a cost-effective chemical synthesis method to produce antimicrobial cocktails, which was based on the heat conjugation of amino acids in the presence of phosphoric acid and plant oil at 150 °C. The conjugates showed potent biological activities against all tested bacteria including a multi-drug resistant Staphylococcus aureus strain Y5 and ampicillin resistant Pseudomonas aerugenosa ATCC9027 strain, demonstrating potential in agriculture, and prophylactic applications in hospital and community settings.

An efficient route to prepare 3-amino allylic alcohols in excellent regio- and stereoselectivity in the presence of bases by orangoselenium catalysis has been developed. In the absence of bases α,β-unsaturated aldehydes were formed in up to 97% yield. Control experiments reveal that the hydroxy group is crucial for the direct amination.

An efficient route to prepare 3-amino allylic alcohols in excellent regio- and stereoselectivity in the presence of bases by orangoselenium catalysis has been developed. In the absence of bases α,β-unsaturated aldehydes were formed in up to 97% yield. Control experiments reveal that the hydroxy group is crucial for the direct amination.

A suitable oxidative system is crucial to electrophilic selenium catalysis (ESC). This short review offers the overview of recent development in ESC with electrophilic N-F reagents as the oxidants. Several highly selective transformations of alkenes such as allylic or vinylic imidation, pyridination, syn-dichlorination, oxidative cyclization and asymmetric cyclization have been described.