NaOH-Catalyzed Dimerization of Monofunctionalized Hydrofullerenes: Transition-Metal-Free, General, and Efficient Synthesis of Single-Bonded [60]Fullerene Dimers

Unprecedented, transition-metal-free NaOH-catalyzed homo- and cross-dimerizations of monofunctionalized hydrofullerenes are reported. Various single-bonded fullerene dimers were synthesized under mild reaction conditions with remarkably high yields. The use of a NaOH catalyst combined with tetrahydrofuran as a cosolvent under an air atmosphere is critical in achieving highly efficient catalytic dimerization

<i>N</i>‑Methyl Transfer Induced Copper-Mediated Oxidative Diamination of Alkynes

A novel intramolecular oxidative diamination of bis­(2-aminophenyl)­acetylene for the synthesis of the structurally intriguing π-conjugated polyheterocyclic scaffold, 5,10-dihydro­indolo­[3,2-<i>b</i>]­indole (DHII), has been developed under Cu­(hfacac)₂/O₂ oxidation systems. The structure design of bis­(2-amino­phenyl)­acetylene bearing both <i>N</i>,<i>N</i>-dimethylamine and primary amine groups is crucial for constructing the corresponding DHII scaffold. Notably, an intermolecular <i>N</i>-methyl transfer from the nitrogen atom of <i>N</i>,<i>N</i>-dimethylamine to the primary amine takes place, which is a critical step for the successful implementation of the present annulation process

Synthesis of 5<i>H</i>‑Dibenzo[<i>c</i>,<i>e</i>]azepine-5,7(6<i>H</i>)‑diones from Benzamides via Palladium-Catalyzed Double C–H Bond Activation

A convenient and efficient method for the synthesis of 5<i>H</i>-dibenzo­[<i>c</i>,<i>e</i>]­azepine-5,7­(6<i>H</i>)-diones from simple and readily available benzamides is described in this work. The palladium-catalyzed homocoupling of benzamides occurred via ortho-selective double C–H bond activation using the simplest amide CONH₂ as a directing group. The subsequent intramolecular condensation reaction proceeded smoothly to produce 5<i>H</i>-dibenzo­[<i>c</i>,<i>e</i>]­azepine-5,7­(6<i>H</i>)-diones in satisfactory to excellent yields in one pot

Pd-Catalyzed Synthesis of 9,9′-Bifluorenylidene Derivatives via Dual C–H Activation of Bis-biaryl Alkynes

We report a novel Pd-catalyzed alkyne-directed dual C–H activation of bis-biaryl alkynes, which produced important and useful products, 9,9′-bifluorenylidene (9,9′BF) derivatives, in high yields with a broad range of functional group compatibility. The combination of the PdCl₂ catalyst with the MnO₂ oxidant and PivOH additive is vital for realization of the present catalytic transformation. Mechanistic evidence suggests that this intramolecular arene/alkyne annulation may take place through unusual dual C–H activation followed by annulation with alkynes

Carboxylic Acid-Catalyzed Highly Efficient and Selective Hydroboration of Alkynes with Pinacolborane

We have demonstrated for the first time that carboxylic acids are able to catalyze the direct hydroboration of various terminal and internal alkynes with pinacolborane without using any metal catalysts. This unprecedented catalytic hydroboration exhibits a broad functional groups compatibility, giving the corresponding alkenyl diboronates and monoboronates in good to high yields with exclusive regio- and stereoselectivities

Copper-Catalyzed Aza-Diels–Alder Reaction and Halogenation: An Approach To Synthesize 7‑Halogenated Chromenoquinolines

A new halogenation method to construct halogen-substituted quinoline moieties is described. The Cu-catalyzed intramolecular aza-Diels–Alder reaction and halogenation reaction proceeded smoothly under mild conditions to produce the corresponding 7-chloro-6<i>H</i>-chromeno­[4,3-<i>b</i>]­quinolines and 7-chloro-6<i>H</i>-thiochromeno­[4,3-<i>b</i>]­quinolines in satisfactory yields

<i>N</i>‑Methyl Transfer Induced Copper-Mediated Oxidative Diamination of Alkynes

A novel intramolecular oxidative diamination of bis­(2-aminophenyl)­acetylene for the synthesis of the structurally intriguing π-conjugated polyheterocyclic scaffold, 5,10-dihydro­indolo­[3,2-<i>b</i>]­indole (DHII), has been developed under Cu­(hfacac)₂/O₂ oxidation systems. The structure design of bis­(2-amino­phenyl)­acetylene bearing both <i>N</i>,<i>N</i>-dimethylamine and primary amine groups is crucial for constructing the corresponding DHII scaffold. Notably, an intermolecular <i>N</i>-methyl transfer from the nitrogen atom of <i>N</i>,<i>N</i>-dimethylamine to the primary amine takes place, which is a critical step for the successful implementation of the present annulation process

Co-Catalyzed Radical Cycloaddition of [60]Fullerene with Active Dibromides: Selective Synthesis of Carbocycle-Fused Fullerene Monoadducts

An efficient and highly selective Co-catalyzed radical cycloaddition of [60]fullerene with active dibromides for the synthesis of three-, five-, six-, and seven-membered carbocycle-fused fullerene monoadducts has been reported. The controlled experiments unambiguously disclosed that the reaction proceeds through the formation of a fullerene monoradical as a key intermediate

Synthesis of Quinazolin-4(3<i>H</i>)‑ones via the Reaction of 2‑Halobenzamides with Nitriles

This paper describes a convenient method to synthesize quinazolin-4­(3<i>H</i>)-ones from simple and readily available 2-halobenzamides and nitriles. The Lewis acid Cu-catalyzed nucleophilic addition of 2-halobenzamide to nitriles followed by S_NAr reaction proceeds smoothly in the presence of ^<i>t</i>BuOK as a base to produce quinazolinone derivatives