Copper-Catalyzed Radical Selenodifluoromethylation of Alkenes: Access to CF2-Containing γ-Lactams

Copper-catalyzed domino synthesis of benzo[d]imidazo[5,1-b][1,3]selenazoles involving sequential intermolecular cycloaddition and intramolecular Ullmann-type C–Se bond formation

A copper-catalyzed domino synthesis of benzo[d]imidazo[5,1-b][1,3]selenazoles involving sequential intermolecular cycloaddition and intramolecular Ullmann-type C–Se bond formation has been developed.

Photocatalytic intramolecular radical cyclization involved synergistic SET and HAT: synthesis of 3,3-difluoro-γ-lactams

A mild and metal-free protocol for visible-light induced intramolecular radical cyclization of N-allyl(propargyl)-2-bromo-2,2-difluoro-N-arylacetamide has been developed.

Silver-catalyzed decarboxylative radical relay difluoroalkylation–carbocyclization: convenient access to CF2-containing quinolinones

A practical Ag-catalyzed formal decarboxylation and radical difluoroalkylation–carbocyclization–hydrolysis route is established to construct a series of structurally diverse CF2-containing N-heterocycles.

The sunlight-promoted aerobic selective cyclization of olefinic amides and diselenides

A novel sunlight-promoted approach for the selective synthesis of selenated iminoisobenzofurans or isoindolinones via the aerobic O-cyclization or N-cyclization of olefinic amides with diselenides has been developed.

Visible light-promoted synthesis of pyrrolidinone derivatives via Rose Bengal as a photoredox catalyst and their photophysical studies

This protocol demonstrates the eco-friendly and sustainable synthesis of pyrrolidinone derivatives using a photocatalyst under irradiation from blue LEDs and their photophysical studies.

Continuous-flow electrosynthesis of selenium-substituted iminoisobenzofuran via oxidative cyclization of olefinic amides and diselenides

A novel method for the continuous synthesis of selenated iminoisobenzofurans by cyclization of olefinic amides with diselenides through electrochemical oxidation under metal-free and oxidant-free conditions has been developed.

Copper/DTBP-Promoted Oxyselenation of Propargylic Amines with Diselenides and CO2: Synthesis of Selenyl 2-Oxazolidinones

A highly efficient electrophilic oxyselenation of propargylic amines with diselenides and CO₂ under atmospheric pressure promoted by copper/DTBP is reported. Various biologically important selenyl 2-oxazolidinones were produced in moderate to excellent yields. The developed method features a broad substrate scope, easy scalability, and mild reaction conditions.

Stereoselective synthesis of fully substituted ethylenes via an Ag-catalyzed 1,6-nucleophilic addition/annulation cascade

A catalytic 1,6-nucleophilic addition/annulation cascade was developed for the first time, and used to produce 27 hitherto unreported ethylene-linked 1-naphthol-imidazole pairs with generally good yields and complete stereoselectivity. An Ag₂O-catalyzed reaction of yne-allenone esters with tosylmethyl isocyanide proceeded efficiently, and provided a simple and convergent protocol for the synthesis of fully substituted (Z)-ethylenes whereas tetrasubstituted (E)-ethylenes were obtained when ethyl isocyanoacetate was employed in this transformation. The reaction pathway consists of [2+2] cycloaddition, 1,6-nucleophilic addition and [3+2] cycloaddition, leading to continuous multiple bond-forming events including C-C and C-N bonds to construct complex molecules.

Electrochemical Synthesis of Spiro[4.5]trienones through Radical-Initiated Dearomative Spirocyclization

A novel and green route has been developed for the electrochemical synthesis of spiro[4.5]trienones through radical-initiated dearomative spirocyclization of alkynes with diselenides. This metal-free and oxidant-free electrosynthesis reaction was performed in an undivided cell under mild conditions. A variety of selenation spiro[4.5]trienones products were prepared in moderate-to-good yields, showing a broad scope and functional group tolerance. Moreover, the developed continuous-flow system combined with electrosynthesis possesses the potential to achieve scaled-up reactions, overcoming the low efficiency of conventional electrochemical scaled-up reactions.

Visible-Light-Induced, Catalyst-Free Radical Cross-Coupling Cyclization of N-Allylbromodifluoroacetamides with Disulfides or Diselenides

A visible-light-induced, catalyst-free radical cross-coupling cyclization of diselenides or disulfides with N-allylbromodifluoroacetamide has been developed. This developed protocol exhibits good functional group tolerance and affords a variety of 4-thio- and 4-seleno-substituted 3,3-difluoro-γ-lactams in moderate to good yields. Based on control experiments, a plausible radical-radical cross-coupling pathway is proposed.

An organoselenium-catalyzed N1- and N2-selective aza-Wacker reaction of alkenes with benzotriazoles

A novel and practical organoselenium-catalyzed, N¹- and N²-selective controllable aza-Wacker reaction is realized, which provides an easy access to N¹- and N²-olefinated benzotriazole derivatives.

Synthetic methods for compounds containing fluoro-lactam units

This review highlights recent progress in the construction of fluorinated lactams, including fluoro-β-lactams, fluoro-γ-lactams, and fluoro-δ-lactams, with an emphasis on the scopes, limitations and mechanisms of these different reactions.

Copper-catalyzed regioselective sulfonylcyanations of vinylarenes

A set of copper-catalyzed sulfonylcyanations of vinylarenes with readily accessible arylsulfonyl chlorides and trimethyl cyanide was achieved, providing a streamlined route to various decorated β-sulfonyl nitriles with good regioselectivity and functional group tolerance.

Recent advances in tandem selenocyclization and tellurocyclization with alkenes and alkynes

This review highlights recent progress in tandem selenocyclization and tellurocyclization with alkenes and alkynes, with an emphasis on the scopes, limitations and mechanisms of these different reactions.

tert-Butyl peroxide (TBHP)/KI-mediated dual C(sp2)-H bond amination of arylamines with α-diazo carbonyls toward 1,2,4-benzotriazines

A new radical-induced dehydrogenative heterocyclization of arylamines with α-diazo carbonyls has been established under metal-free oxidative conditions, enabling two-fold C(sp2)-H bond amination to access a wide range of functionalized 1,2,4-triazine derivatives with generally good yields by combining KI/tert-butyl peroxide (TBHP). The present protocol features wide substrate scope, commercial accessibility, and mild reaction conditions. Mechanistic details of this radical process are rendered by conducting systematic theoretical calculations.

Direct methyl C(sp3)-H azolation of thioanisoles via oxidative radical coupling

A method for metal-free, 1,3-dibromo-5,5-dimethylhydantoin mediated methyl C(sp³)-H bond azolation of thioanisoles has been developed, affording a facile route for the construction of nitrogen-functionalized thioanisoles, possibly via a nitrogen-centered radical process. This reaction represents an important addition to the limited number of existing methods for the methyl C(sp³)-H bond functionalization of thioanisoles, and may find practical application in the synthesis of nitrogen-alkylated azoles.

Copper/B2pin2-Catalyzed Difluoroalkylation of Methylenecyclopropanes with Bromodifluorinated Acetates and Acetamides: One-Pot Synthesis of CF2-Containing Dihydronaphthalene Derivatives

Novel copper/B₂pin₂-catalyzed difluoroalkylation of methylenecyclopropanes with bromodifluorinated acetates and acetamides via a tandem radical process involving ring-opening/intramolecular cyclization has been reported. This protocol is not only tolerated to a diverse range of substrates but also applicable to the synthesis of useful difluoromethylated compounds. Moreover, the reaction could be performed on a gram scale with a high yield, which opens up the possibility for practical applications.

Silver-mediated oxidative 1,2-alkylesterification of styrenes with nitriles and acids via C(sp3)–H functionalization

A new silver-mediated 1,2-alkylesterification of alkenes with nitriles and acids promoted by a catalytic amount of nickel catalyst for producing acyloxylated nitriles has been developed via a C(sp³)–H functionalization process.

Combined inorganic base promoted N-addition/[2,3]-sigmatropic rearrangement to construct homoallyl sulfur-containing pyrazolones

The first sequentially combined inorganic base promoted N-addition/[2,3]-sigmatropic rearrangement reaction of α-alkylidene pyrazolinones and propargyl sulfonium salts has been reported to construct homoallyl sulfur-containing pyrazolones with moderate to excellent yields. α-Alkylidene pyrazolinones function as N-nucleophilic agents distinguished from the reported C-addition reactions. Propargyl sulfonium salts were first involved in the [2,3]-sigmatropic rearrangement protocol differentiated from the well-established annulation reactions. The excellent regioselectivity, the broad scope of substrates, gram-scale synthesis and convenient transformation embody the synthetic superiority of this cascade process.

The combined inorganic base promoted N-addition/[2,3]-sigmatropic rearrangement of α-alkylidene pyrazolinones and propargyl sulfonium salts has been reported to construct homoallyl sulfur-containing pyrazolones with moderate to excellent yields.