Copper-Catalyzed Denitrogenative Radical Cyclization of 3-Aminoindazoles with -Cyanoarylacrylamides: Synthesis of Cyanoarylated Quinoline-2,4(1,3)-diones.

A copper-catalyzed denitrogenative radical cyclization of 3-aminoindazoles with -cyanoarylacrylamides has been developed, enabling the efficient synthesis of a variety of cyanoarylated quinoline-2,4(1,3)-diones in moderate to good yields at room temperature. Notably, this strategy overcomes the traditional challenge of the low reactivity of nitrile groups toward radical addition by utilizing cyanoaryl radicals generated from 3-aminoindazoles as reactive intermediates. Mechanism studies indicate that 2-cyanophenyl radicals, generated through the cleavage of two C-N bonds of 3-aminoindazoles, served as the key intermediates initiating the cyclization process.

Hypervalent Iodine(III)-Promoted Cyclization of Imidazoles with Alkenes: Divergent Synthesis of Ring-Fused Tricyclic Imidazoles Bearing Azide or Exocyclic Olefin Substituents.

We present the first example of a hypervalent iodine(III)-promoted cyclization of imidazoles with alkenes using readily available TMSN to synthesize azide-substituted tricyclic imidazoles in 1 h. By altering the solvent to water and adjusting the reaction temperature, exocyclic alkenes can be obtained via HN elimination. The method offers broad substrate scope (30-99% yields, 24 examples) and proceeds via an azidyl radical generated by iodine(III)-mediated oxidation of TMSN.

Insertion of Arynes into the C-C σ-Bond of α-Pentafluorosulfanyl Ketones: Access to 2-(Pentafluorosulfanyl)methyl Benzophenones.

The incorporation of the pentafluorosulfanyl (SF) group into organic molecules is highly significant due to its unique physicochemical properties and potential applications in pharmaceuticals and agrochemicals. However, general and efficient methods for the synthesis of benzylic SF-containing compounds remain unexplored. Herein, we report the synthesis of a series of 2-(pentafluorosulfanyl)methyl benzophenones via the insertion of arynes into the C-C σ-bond of α-pentafluorosulfanyl ketones.

Visible-light-promoted radical cyclisation of unactivated alkenes in benzimidazoles: synthesis of difluoromethyl- and aryldifluoromethyl-substituted polycyclic imidazoles.

An efficient and eco-friendly approach for synthesizing difluoromethyl- and aryldifluoromethyl-substituted polycyclic imidazoles was established via a visible-light-promoted radical cyclization reaction. This method employed the readily accessible and inexpensive CFHCOH or PhCFCOOH, along with benzimidazoles bearing unactivated alkenes and PhI(OAc) as substrates, and proceeded without the need of any base, metal catalyst, photocatalyst or additive. In total, 24 examples were examined, and all of them successfully underwent cyclization reaction to produce the target products in good to excellent yields.

Photoredox-Catalysis Fluorosulfonyldifluoromethylation of Unactivated Alkenes and (Hetero)arenes with ICFSOF.

The fluorosulfonyldifluoromethylation of unactivated alkenes and (hetero)arenes with iododifluoromethanesulfonyl fluoride (ICFSOF) under visible light photoredox catalysis was successfully developed. Key to the successful fluorosulfonyldifluoromethylation of aromatic compounds was the usage of AgOTf as an additive to promote the formation of the CFSOF radical. The protocol provided a straightforward way to introduce the interesting and useful CFSOF group on sp and sp carbons.

Palladium/Norbornene Cooperatively Catalyzed Modular Trifunctionalization of 2-Bromoaryl Ketone via a Decarbonylation Process.

Palladium/norbornene cooperatively catalyzed Catellani-type reactions were normally limited to aryl iodides as substrates. The employment of aryl bromides has remained challenging. Herein a Pd/NBE cooperatively catalyzed Catellani-type reaction of 2-bromoaryl ketone is described.

Silver-Catalyzed Cascade Radical Bicyclization Reaction: An Atom- and Step-Economical Strategy Accessing γ-Lactam Containing Isoquinolinediones.

An efficient and convenient method for the cascade radical bicyclization of -phenyl-4-pentenamides with -methyl--methacryloylbenzamides under silver-catalyzed conditions is described. Based on this newly developed strategy, a variety of valuable γ-lactam containing isoquinolinediones can be effectively synthesized in one step within 0.5 h, during which two C-C bonds, one C-N bond, and two new -heterocycles were formed concurrently.

Synthesis of cyano-substituted γ-lactams through a copper-catalyzed cascade cyclization/cyanation reaction.

A convenient copper-catalyzed cascade cyclization/cyanation reaction for the construction of cyano-containing γ-lactams was developed. The protocol employed TMSCN as the cyano source and proceeded in water under simple conditions. Mechanistic studies indicated this reaction involved an amidyl radical initiated cascade 5- cyclization/cyanation process.

Silver-catalyzed cascade cyclization and functionalization of -aryl-4-pentenamides: an efficient route to γ-lactam-substituted quinone derivatives.

The synthesis of γ-lactam-substituted quinone derivatives through a AgO-catalyzed cascade cyclization and functionalization of -aryl-4-pentenamides has been developed. Related 2-oxazolidinone substituted quinone products can be also obtained with -aryl allyl carbamates. The reactions proceed through an amidyl radical-initiated 5--trig cyclization and followed radical addition to quinones.

Synthesis of organic liquid crystals containing selectively fluorinated cyclopropanes.

This paper describes the synthesis of a series of organic liquid crystals (LCs) containing selectively fluorinated cyclopropanes at their termini. The syntheses used difluorocarbene additions to olefin precursors, an approach which proved straightforward such that these liquid crystal candidates could be efficiently prepared. Their physical and thermodynamic properties were evaluated and depending on individual structures, they either displayed positive or negative dielectric anisotropy.

Unexpected α,α'-difluoroethers from Ag(i)F and N-bromosuccinimide reactions of dibenzo[a,e]cyclooctatetraene.

An unexpected and highly efficient reaction of dibenzo[a,e]cyclooctatetraene with Ag(i)F and N-bromosuccinamide in dichloromethane results in a sequential ring contraction pathway to generate bridged bicyclic α,α'-difluoroether isomers 10 and 11 where the ether oxygen is isotopically labelled from oxygen-18 water. In diethyl ether the same reaction generates the more classical vicinal difluoride isomers 13 and 14.

Fluorine containing cyclopropanes: synthesis of aryl substituted all-cis 1,2,3-trifluorocyclopropanes, a facially polar motif.

The syntheses of substituted all-cis-1,2,3-trifluorocyclopropanes are described for the first time. The three fluorines located on each of the cyclopropyl carbons with a stereochemistry where they are all on the same face of the cyclopropane, imparts a significant polarity to the molecule, and the inherent conformational rigidity and lowering of log P makes this motif attractive for exploration as a substituent for pharmaceuticals and agrochemicals research.

Polar alicyclic rings: synthesis and structure of all cis-1,2,3,4-tetrafluorocyclopentane.

The all-cis isomer of 1,2,3,4-tetrafluorocyclopentane is prepared and characterised by NMR and X-ray crystallography and the experimental structure compared with theory. The structure has a similarly high polarity to all-cis tetrafluorocyclohexanes despite the increased conformational flexibility of a cyclopentane.

Formation and characterization of silver nanoparticles in aqueous solution via ultrasonic irradiation.

In this study, a simple and green method to synthesize silver nanoparticles (Ag NPs) in aqueous solution via ultrasonic irradiation has been developed. Ultrafine Ag NPs with average diameter of 8 nm were obtained through sonicating aqueous solution of sodium hydroxide (NaOH, 0.1 mM) with adding silver nitrate solution (AgNO3, 5.