Defluorinative Cyclization of Enamides with Fluoroalkyl Halides Through Two Vicinal C(sp)─F Bonds Functionalization.

Introducing distinctive functional groups to expand the structural diversity and improve the intrinsic properties of parent molecules has been an essential pursuit in organic chemistry. By using perfluoroalkyl halide (PFAH) as a nontraditional, readily available, ideal 1,2-difluoroalkenyl coupling partner, a defluorinative cyclization reaction of enamides for the construction of fluoroalkenyl oxazoles is first developed. The selective and controllable two-fold cleavage of vicinal C(sp)─F bonds in PFAH not only enables the introduction of a specific 1,2-difluoroalkenyl moiety with ease but also results in the functionalization of two C(sp)─H bonds of enamides without the need for metal catalyst, photocatalyst, oxidant, or light.

Modular Synthesis of Furans with Four Nonidentical Substituents by Aqueous Defluorinative Reaction of Trifluoromethyl Enones with Two Nucleophiles.

A three-component reaction of trifluoromethyl enones, phosphine oxides, and alcohols in water solution is developed. This defluorinative reaction occurs through a cascade process involving defluorophosphorylation, defluoroalkyloxylation, and defluoroheteroannulation, enabling the modular synthesis of furans with four distinct substituents: 2-alkyloxy, 3-trifluoromethyl, 4-phosphoryl, and 5-(hetero)aryl groups. Moreover, apart from alcohol substrates, the scope of nucleophiles could be further extended to phenols, azacycles, or sulfonamide.

Defluorinative Diazolation-Cyclization Relay for Synthesis of Furan-Bridged Triheterocycles and Colorimetric Sensor Application.

Polyaromatics, as the assembly of diverse cyclic π-systems, exhibit unique physicochemical properties when compared to their individual constituents. In this study, we developed a strategic connection of two azacycles via a furan bridge through a defluorinative diazolation-cyclization reaction of trifluoromethyl enones and N-heterocycles. A range of modular 2,4-furan-bridged triheterocycles (FBTHs), featuring a C3-trifluoromethyl group, was synthesized with broad substrate scope and good regioselectivity under transition metal-free conditions.

Switchable Divergent Electrochemical Hydrodehalogenation of -Dihalocyclopropanes.

A comprehensive and effective electrochemical methodology is introduced for the diverse hydrodechlorination of -dichlorocyclopropanes and the ring cleavage hydrodefluorination of -difluorocyclopropanes under uniform electrochemical conditions. Moreover, the water content allows for the adjustable monohydrodechlorination or dihydrodechlorination of -dichlorocyclopropanes with exceptional chemoselectivity. Additionally, the mildness and practicality of this protocol facilitate its application to the late-stage functionalization of bioactive molecules.

Combining (CHO) and (NH)CO as a Formamidine Equivalent for "Four-in-One" Synthesis of Fluoroalkylated 2--Pyrimidines.

Multicomponent reactions hold the potential to maximize the synthetic efficiency in the preparation of diverse and complex molecular scaffolds. An unprecedented formal [3+1+1+1] annulation approach for the one-step synthesis of fluoroalkylated 2--pyrimidines commencing from perfluoroalkyl alkenes, paraformaldehyde, and ammonium carbonate is described. By harnessing readily accessible (CHO) and cheap (NH)CO as a formamidine surrogate, this method effectively replaces traditionally preformed amidines with a pyrimidine assembly.

Silver-Promoted Three-Component Synthesis of Perfluoroalkenyl Pyrroles through Partial Defluorinative Functionalization of Perfluoroalkyl Halides.

A silver-promoted three-component heterocyclization of alkynes, perfluoroalkyl halides, and 1,3-dinucleophiles was developed for the efficient synthesis of privileged ()-perfluoroalkenyl pyrroles. The reaction proceeded through a rationally designed sequence of radical perfluoroalkylation and intramolecular defluorinative [3 + 2]-heterocyclization. The utility of perfluoroalkyl halide as a perfluoroalkenyl reagent, by selective and controllable functionalization of two inert C(sp)-F bonds at vicinal carbon centers on the perfluoroalkyl chain, provides a new reaction mode for the synthesis of value-added organofluorides starting from the easily available and low-cost fluorinated feedstock.

Hydroboration and hydrosilylation of alkenes catalyzed by an unsymmetrical magnesium methyl complex.

The hydroboration and hydrosilylation of alkenes catalyzed by the unsymmetrical β-diketiminate magnesium methyl complex [(Nacnac)MgMe (THF)] (1) have been reported. When complex 1 was employed as a highly efficient catalyst in the hydroboration of various alkenes with HBpin, only the -Markovnikov hydroboration products were obtained in high yields and with high regioselectivities under mild reaction conditions (60 °C). To our surprise, it showed different regioselectivities in the hydrosilylation of a range of alkenes with PhSiH.

Reactivity and reaction pathways of peroxymonosulfate and peroxydisulfate with neonicotinoid insecticides.

Neonicotinoid insecticides (NNIs), which have been detected across diverse aquatic environments, have sparked substantial concerns regarding their potential adverse ecological and health risks. In this study, the removal of NNIs by unactivated peroxymonosulfate (PMS) and peroxydisulfate (PDS) was systematically investigated. Results showed that PMS/PDS direct oxidation is mainly responsible for the degradation of imidacloprid (IMD), and the degradation kinetics can be well described by a second-order kinetics model, first-order in both IMD and PMS/PDS concentration.

Cooperative effects of SIRT1 and SIRT2 on APP acetylation.

Alzheimer's disease (AD) is an age-related neurodegenerative disorder characterized by amyloid-β (Aβ) deposition and neurofibrillary tangles. Although the NAD -dependent deacetylases SIRT1 and SIRT2 play pivotal roles in age-related diseases, their cooperative effects in AD have not yet been elucidated. Here, we report that the SIRT2:SIRT1 ratio is elevated in the brains of aging mice and in the AD mouse models.

Combining Hydrodefluorination and Defluorophosphorylation for Chemo- and Stereoselective Synthesis of -Fluorophosphine Alkenes.

A chemo-, regio-, and stereoselective reaction of trifluoromethyl enones, phenylsilane, and phosphine oxides through a sequential hydrodefluorination and defluorophosphorylation relay is developed for the synthesis of distinctive -fluorophosphine alkenes. This multicomponent reaction occurred under transition-metal-free conditions with good functional group tolerance. Moreover, the preinstalled carbonyl auxiliary is important for tuning the reactivity of β-trifluoromethyl enones, thereby enabling controllable and selective functionalization of two fluorine atoms in trifluoromethylated enones.

Defluorinative Thiolation of -Difluoroalkenes by Convergent Paired Electrolysis.

Herein, we have successfully developed a convergent paired electrolysis strategy for the defluorinative thiolation process utilizing thiols and -difluoroalkenes as precursors. This protocol exhibits remarkable tolerance toward a wide range of functional groups, as exemplified by the successful late-stage defluorothiolation of complex molecules. Additionally, this strategy is amenable to gram-scale synthesis, making use of both anodic oxidation and cathodic reduction processes in an efficient manner.

Regioselective Deuteration of Arenes Enabled by Simple Heterogeneous Palladium Catalysis.

A heterogeneous redox-neutral palladium-catalytic platform was reported for the preparation of deuterated (hetero) arenes from (hetero) arenes mediated by regioselective C(sp)-H thianthrenation utilizing commercially available and recyclable Pd/C catalyst. A wide range of deuterated compounds could be obtained in high yields with excellent levels of deuterium incorporation under these simple heterogeneous catalytic conditions with the requirement of stable and easily handled DCOONa as a deuterium source. The late-stage deuteration of pharmaceuticals and bioactive molecules was also achieved by this approach.

Nickel-Catalyzed Direct Cross-Coupling of Unactivated Aryl Fluorides with Aryl Bromides.

A nickel-catalyzed direct cross-coupling of unactivated aryl fluorides with aryl bromides is realized. The one-pot reaction, which avoids the use of preformed and sensitive organometallic reagents, proceeds effectively via C-F bond cleavage at room temperature in THF in the presence of the phosphine ligand and magnesium powder (with or without TMSCl) to produce the desired biaryls in modest to good yields.

NaS·9HO Enabled Defluorodisulfuration and Hydrodefluorination of Perfluorobutyl Tetralones: Synthesis of Trifluoromethyl 1,2-Dithioles.

An unprecedented defluorocyclization of perfluorobutyl tetralones with NaS·9HO was developed for the synthesis of trifluoromethyl 1,2-dithioles, which provided chemists novel access to biologically and pharmaceutically relevant organofluorides. Successive C(sp)-F bond functionalization at the perfluoroalkyl chain is vital for the formation of four C-H/C-S/S-S bonds and a five-membered S-heterocycle assembly. Cheap, weakly toxic, and odorless inorganic sulfide NaS·9HO acts as both a disulfurating precursor and a hydrodefluorinating reagent in this tandem multi-bond-interconverting reaction.

Selective and Controllable Defluorophosphination and Defluorophosphorylation of Trifluoromethylated Enones: An Auxiliary Function of the Carbonyl Group.

The auxiliary function of a carbonyl group in the tunable defluorophosphination and defluorophosphorylation of trifluoromethylated enones with P(O)-containing compounds was demonstrated. Controlled replacement of one or two fluorine atoms in trifluoromethylated enones while maintaining high chemo- and stereoselectivity was achieved under mild conditions, thus enabling diversity-oriented synthesis of skeletally diverse organophosphorus libraries─()-difluoro-1,3-dien-1-yl phosphinates, (1,3)-4-phosphoryl-4-fluoro-buta-1,3-dien-1-yl phosphinates, and ()-4-phosphoryl-4-fluoro-1,3-but-3-en-1-ones─in good yields with excellent functional group tolerance.

De-ubiquitination of SAMHD1 by USP7 promotes DNA damage repair to overcome oncogenic stress and affect chemotherapy sensitivity.

Oncogenic stress induces DNA damage repair (DDR) that permits escape from mitotic catastrophe and allows early precursor lesions during the evolution of cancer. SAMHD1, a dNTPase protecting cells from viral infections, has been recently found to participate in DNA damage repair process. However, its role in tumorigenesis remains largely unknown.

Magnesium halide-catalyzed hydroboration of isocyanates and ketones.

Alkaline-earth metals have attracted increasing attention because they are cheap, Earth abundant and environmentally friendly, and have gradually become inexpensive and sustainable alternatives to traditional precious transition metal catalysts in many organic reactions. Recently, the hydroboration of unsaturated organic substrates has been extensively investigated. However, reports on alkaline-earth metal catalyzed hydroboration of isocyanates and ketones are rare.

Metallic and Dimensional Optimization of Metal-Organic Frameworks for High-Performance Lithium-Sulfur Batteries.

Lithium-sulfur batteries (LSBs) have been considered as one of the most promising energy storage systems owing to their high theoretical energy density and abundant sulfuric resources. However, their commercial application is limited by rapid capacity decline and low Coulombic efficiency. Metal-organic frameworks (MOFs) made of metallic nodes and organic ligands can suppress polysulfide shuttling and promote redox kinetics.

Rhodium-Catalyzed Asymmetric Annulation of Unactivated Alkynes with 3-(-Boronated Aryl) Conjugated Enones: Enantioselective Synthesis of 2,3-Disubstituted Indenes.

A rhodium-catalyzed tandem arylation/cyclization reaction of 3-(ortho-boronated aryl) conjugated enones with unactivated alkynes is reported. By using a rhodium(I)/chiral-diene complex as the catalyst, the protocol was processed smoothly to provide various 2,3-disubstituted indene compounds in high yields with excellent regioselectivities and enantioselectivities. The approach outlined herein is appealing, as simple diarylalkynes, diakylalkynes, and alkyl(aryl)alkynes are the starting materials.

Nickel-Catalyzed Direct Cross-Coupling of Aryl Fluorosulfates with Aryl Bromides.

A one-pot, direct cross-coupling of aryl fluorosulfate with aryl bromide, which is step-economical and avoids the use of a preprepared/commercial organometallic reagent, could be accomplished by performing the reaction in THF at room temperature in the presence of nickel catalyst, magnesium turnings, and lithium chloride, giving rise to the corresponding biaryls in moderate to good yields with reasonable functional group compatibility.

Nickel-Catalyzed Direct Cross-Coupling of Aryl Thioether with Aryl Bromide.

A straightforward cross-coupling of aryl thioether with aryl bromide with the aid of nickel salt, magnesium, and lithium chloride in tetrahydrofuran at ambient temperature was accomplished. The one-pot reactions proceeded efficiently via C-S bond cleavage to produce the desired biaryls in modest to good yields, avoiding the use of pregenerated or commercial organometallic reagents.