An efficient and operationally simple method for the synthesis of β-keto sulfones through the BF·OEt-promoted reaction of alkynes and sodium sulfinates is developed. With its facile and selective access to the targets, it features good functional group compatibility, mild conditions, easily available starting materials, and good yields. Notably, the reaction does not require metal catalysts or chemical reagents with pungent odors.
View Article and Find Full Text PDF-Alkyl glycosides, an important class of C-glycosides, are widely found in various drugs and natural products. The synthesis of -alkyl glycosides has attracted considerable attention. Herein, we developed a Ni/photoredox catalyzed decarboxylative ()-() coupling reaction of stable glycosylcarboxylic acids with simple aliphatic bromides to generate C-alkyl glycosides.
View Article and Find Full Text PDFPyrrolidine (PyD) has an important impact on the environment and human health. However, there is currently no method for trace detection of PyD. Here, we successfully designed diaminomethylene-4H-pyran (1) as the first specific fluorescent probe for PyD.
View Article and Find Full Text PDFTo investigate the significance of atherosclerotic plaque location in hybrid surgery comprising both endovascular recanalization approaches and carotid endarterectomy for symptomatic atherosclerotic non-acute long-segment occlusion of the internal carotid artery (ICA), 162 patients were enrolled, including 120 (74.1%) patients in the proximal plaque group and 42 (25.9%) in the distal plaque group.
View Article and Find Full Text PDFThis study reports selective dual amino acylation and C-H bromination of aniline compounds enabled by Cu/O catalyst systems. This method involves crucial oxidation-induced C-CN bond cleavage of α-methylene nitriles to generate an acylcyanide intermediate that is facilely intercepted by anilines. After amino acylation, the Cu(II) precatalyst in combination with NBS generates Cu(III)-Br in situ that engages in selective electrophilic - or -C-H bromination.
View Article and Find Full Text PDFWith in-depth research on 1,2-difunctionalization, remote difunctionalization has garnered widespread attention for achieving multifunctionality. Herein, we report a strategy for achieving remote difunctionalization under mild conditions. This strategy exhibited good substrate suitability and functional group tolerance.
View Article and Find Full Text PDFHerein, we present a novel Catellani-type reaction that employed aryl-thianthrenium salts as aryl substrates to trigger the subsequent palladium/norbornene cooperatively catalyzed progress. This strategy can achieve site-selective C-H difunctionalization of aryl compounds without directing groups or a known initiating reagent. A series of functionalized syntheses of bioactive molecules further demonstrated the potential of this strategy.
View Article and Find Full Text PDFA highly efficient and operationally simple method for the synthesis of β-sulfinyl alkenylsulfones through a BF·OEt-promoted reaction of alkynes and sodium sulfinates is developed, successfully avoiding the complicated anhydrous treatment before the reaction and greatly simplifying the reaction conditions. As a facile and selective route to the targets, it features good functional group compatibility, mild conditions, easily available starting materials, and excellent yields. Notably, the trace water in solvent plays a key role in promoting the reaction, which provides a more practical pathway for the utilization of the BF·OEt catalytic system.
View Article and Find Full Text PDFA visible-light-induced glycoarylation of activated olefins has been accomplished. Glycosyl radicals are generated via radical transfer strategies between (TMS)SiOH and glycosyl bromides. Subsequent radical translocation and rapid 1,4-aryl migration form β-sugar amide derivatives, and eight types of sugars are compatible with this reaction.
View Article and Find Full Text PDFPolysubstituted alkenes are an important class of organic intermediates that widely exist in various natural products and drug molecules. Herein, we reported a stereoselective synthesis of multisubstituted alkenes via ruthenium-catalyzed remote migration arylation of nonactivated olefins. This strategy exhibited wide substrate suitability and excellent functional group tolerance.
View Article and Find Full Text PDFWe report a redox-neutral, visible-light-mediated difluoroalkylation of unactivated C(sp)-H bonds in amides via nitrogen-centered radicals triggered intramolecular hydrogen atom transfer. Notably, all types (tertiary, secondary, and primary) of γ-C(sp)-H bonds displayed excellent reactivity. This methodology presents a facile route for the regioselective introduction of α,α-difluoroketone fragments into organic molecules.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
December 2022
Intensifying climate change significantly impacts residential electricity consumption, especially in developing countries, such as China, that are experiencing rapid income growth. By combining meteorological and monthly household consumption survey data, this study explores the response function of residential electricity consumption to temperature in China from a micro perspective. Future residential electricity demands and related CO emissions are then forecast under different climate scenarios.
View Article and Find Full Text PDFHerein, we describe the copper-catalyzed arylalkylation of activated alkenes via hydrogen-atom transfer and aryl migration strategy. The reaction was carried out through a radical-mediated continuous migration pathway using -fluorosulfonamides as the alkyl source. The primary, secondary, and tertiary alkyl radicals formed by intramolecular hydrogen-atom transfer proceeded smoothly.
View Article and Find Full Text PDFC-aryl glycosides are popular basic skeletons in biochemistry and pharmaceutical chemistry. Herein, ruthenium-catalyzed highly stereo- and site-selective ortho- and meta-C -H glycosylation is described. A series of C-aryl pyranosides and furanosides were synthesized by this method.
View Article and Find Full Text PDFConstruction of C(sp)-C(sp) bonds regioselective coupling of C(sp)-H/C(sp)-H bonds is challenging due to the low reactivity and regioselectivity of C-H bonds. Here, a novel photoinduced Ru/photocatalyst-cocatalyzed regioselective cross-dehydrogenative coupling of dual remote C-H bonds, including inert γ-C(sp)-H bonds in amides and -C(sp)-H bonds in arenes, to construct -alkylated arenes has been accomplished. This metallaphotoredox-enabled site-selective coupling between remote inert C(sp)-H bonds and -C(sp)-H bonds is characterized by its unique site-selectivity, redox-neutral conditions, broad substrate scope and wide use of late-stage functionalization of bioactive molecules.
View Article and Find Full Text PDFWe described a novel palladium-catalyzed C-H glycosylation of indole or tryptophan for a one-pot stereoselective synthesis of 2,3-diglycosylindoles and tryptophan-C-glycosides. In this strategy, the use of air and base-free and ligand-free conditions provided a highly efficient route to construct C-glycosides. The method can be applied to a wide range of cost-effective and convenient glycosyl chloride donors.
View Article and Find Full Text PDFChem Commun (Camb)
March 2022
This manuscript describes an unusual Pd-catalyzed rearrangement reaction. It provides efficient access to 1-phenanthrol derivatives using allyloxy-tethered aryl iodides. This rearrangement process involves the cleavage of a C-I bond, a C-O bond and C-H bonds, and the formation of two C-C bonds in one-pot.
View Article and Find Full Text PDFHerein, we realized the multicomponent reactions of phenol derivatives via a six-membered cycloruthenated intermediate for the first time. This strategy exhibited good substrate suitability and functional group tolerance with various phenol derivatives and provided a potential synthetic drug approach. Mechanistic studies showed that a radical might be involved in this process.
View Article and Find Full Text PDFC-Aryl glycosides are of high value as drug candidates. Here a novel and cost-effective nickel catalyzed ortho-CAr-H glycosylation reaction with high regioselectivity and excellent α-selectivity is described. This method shows great functional group compatibility with various glycosides, showing its synthetic potential.
View Article and Find Full Text PDFWe described a novel palladium-catalyzed domino procedure for the preparation of (hetero)aryl thio/selenoglycosides. Readily available (hetero)aryl iodides and easily accessible 1-thiosugars/1-selenosugars are utilized as the substrates. Meanwhile, 10 types of sugars are quite compatible with this reaction with good regio- and stereoselectivity, high efficiency, and broad applicability (up to 89%, 53 examples).
View Article and Find Full Text PDFThis Letter describes a Pd-catalyzed Tsuji-Trost-type/Heck reaction with allyloxy-tethered aryl iodides and aziridines. The strategy provides efficient access to benzannulated medium-sized rings via intermolecular cyclization. The substrate aryl iodide has two oxidative addition sites, that is, the aromatic C-I bond and the allyl-oxygen bond.
View Article and Find Full Text PDFA novel dehydrogenative coupling reaction of -fluorocarboxamides with polyfluoroarenes forming C(sp)-C(sp) bonds enabled by copper catalysis has been accomplished. -Fluorocarboxamides are postulated to undergo copper-mediated dehydrogenative cross-coupling reaction with electron-deficient polyfluoroarenes via a radical pathway. Benzylic C-H bonds and aliphatic C-H bonds in -fluorocarboxamides could proceed smoothly and demonstrated excellent regioselectivity.
View Article and Find Full Text PDFWe developed a new transition-metal-free intermolecular Claisen rearrangement process to introduce allyl and allenyl groups into the α position of tertiary amides. In this transformation, amides were activated by trifluoromethanesulfonic anhydride to produce the keteniminium ion intermediates that exhibit strong electrophilic activity. This atom-economical process delivers α position-modified amides under mild conditions in moderate to good yields and showcases a broad substrate compatibility.
View Article and Find Full Text PDFA gold-catalyzed tandem annulation of propargylic alcohols and pyridylhomopropargylic alcohols is achieved, providing an atom-economical approach to a diverse set of polycyclic dihydrobenzofurans in good yields. The reaction proceeds via the 5- cyclization/Meyer-Schuster rearrangement/Friedel-Crafts-type pathway. In this way, three C-C bonds and one C-O bond form to give a polycyclic skeleton in a one-pot process.
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