Palladium-catalyzed difunctionalization/dearomatization of N-benzylacrylamides with α-carbonyl alkyl bromides: facile access to azaspirocyclohexadienones.

An efficient palladium-catalyzed difunctionalization/dearomatization of N-benzylacrylamides with α-carbonyl alkyl bromides as alkyl radical precursors has been described. Various α-carbonyl alkyl bromides, including α-bromoalkyl esters and ketones, reacted smoothly to provide important azaspirocyclohexadienones in moderate to excellent yields. In addition, mechanistic studies suggested that the reaction proceeded via a radical pathway.

Palladium-catalyzed annulations of arynes with 2-(2-iodophenoxy)-1-substituted ethanones.

Palladium-catalyzed annulations of arynes with 2-(2-iodophenoxy)-1-substituted ethanones for the synthesis of 6H-benzo[c]chromenes are presented. This mild route allows formation of two new carbon-carbon bonds via an α-arylation/annulation process.

Palladium-catalyzed cyclocarbonylation of arynes with methyl allyl carbonates: selective synthesis of 1H-inden-1-ones.

A selective protocol for the synthesis of 2-methylene-3-substituted-2,3-dihydro-1H-inden-1-ones and 2-benzylidene-2,3-dihydro-1H-inden-1-ones has been developed via palladium-catalyzed cyclocarbonylation reactions of arynes with allyl carbonates and carbon monooxide (CO). It is noteworthy that the selectivity of this new route is depended on both substrates and ligands.

Selective synthesis of o-acylbenzylphosphonates by insertion reactions of arynes into beta-ketophosphonates.

A mild method for selective synthesis of o-acylbenzylphosphonates has been developed by the reactions of arynes with beta-ketophosphonates. In the presence of CsF and THF, the carbon-carbon sigma-bonds of 2-oxopropylphosphonates were selectively cleaved and added to arynes providing the corresponding 2-acylbenzylphosphonates in moderate to good yields.

Palladium-catalyzed decarboxylative coupling of allylic alkynoates with arynes.

A novel and selective protocol for the synthesis of 1-allyl-2-ethynylbenzenes has been developed by palladium-catalyzed decarboxylative coupling of allylic alkynoates with arynes. This new route allows for both sp-sp(2) and sp(2)-sp(3) couplings of allylic alkynoates with arynes in one pot involving a decarboxylation process.

Palladium-catalyzed cocyclotrimerization of allenes with arynes: selective synthesis of phenanthrenes.

Palladium-catalyzed cocyclotrimerization of allenes with arynes has been developed for selectively synthesizing phenanthrenes. In the presence of [(allyl)PdCl](2) and P(o-tol)(3), a variety of allenes, including internal and terminal allenes, underwent the cocyclotrimerization with arynes to afford the corresponding phenanthrenes in moderate to good yields. The results showed the selectivity of the reaction based on allenes.

Synthesis of (E)-3-(isobenzofuran-3(1H)-ylidene)indolin-2-ones by the palladium-catalyzed intramolecular C-H functionalization process.

A novel and selective protocol has been developed for the synthesis of (E)-3-(isobenzofuran-3(1H)-ylidene)indolin-2-ones by Pd-catalyzed oxidative intramolecular C-H functionalization reactions of various 3-(2-(hydroxymethyl)aryl)-N-methyl-N-arylpropiolamides in moderate yields. Mechanisms involving a C-H activation process were proposed for this transformation on the basis of the observed values of kinetic isotope effects.

Cycloaddition of arynes with iodonium ylides: a mild and general route for the synthesis of benzofuran derivatives.

A mild and general cycloaddition of arynes with iodonium ylides protocol has been developed for the synthesis of benzofurans. In the presence of CsF, ortho-silyl aryltriflates were reacted with iodonium ylides smoothly at room temperature in moderate to good yields.

Sequential intermolecular aminopalladation/ortho-arene C-H activation reactions of N-phenylpropiolamides with phthalimide.

A novel palladium-catalyzed intermolecular aminopalladation/C-H activation method for selectively synthesizing (E)-(2-oxindolin-3-ylidene)phthalimides has been developed. In the presence of Pd(OAc)2 and PhI(OAc)2, alkynes were difunctionalized with a phthalimide and an arene sp2 C-H bond to selectively synthesize (E)-(2-oxoindolin-3-ylidene)phthalimides, which products are of great potential pharmaceutical value products in many major therapeutic areas, such as oncology, inflammation, neurology, immunology, and endocrinology. To the best of our knowledge, the reaction serves as the first example of intermolecular aminopalladation/C-H activation reactions of alkynes.

CuI-catalyzed suzuki-miyaura and sonogashira cross-coupling reactions using DABCO as ligand.

In the presence of TBAB, CuI-catalyzed Suzuki-Miyaura cross-coupling of vinyl halides and aryl halides with arylboronic acids was conducted smoothly to afford the corresponding diarylethenes and polyaryls in moderate to good yields using DABCO (1,4-diazabicyclo[2.2.2]octane) as the ligand. We also found that the inexpensive CuI/DABCO catalytic system was effective for Sonogashira cross-couplings of aryl halides and vinyl halides. A variety of aryl halides and vinyl halides including activated aryl chlorides underwent the coupling with terminal alkynes in moderate to excellent yields.

2-aminopyrimidine-4,6-diol as an efficient ligand for solvent-free copper-catalyzed N-arylations of imidazoles with aryl and heteroaryl halides.

Efficient and solvent-free copper-catalyzed N-arylations of imidazoles with aryl and heteroaryl halides have been demonstrated. In the presence of CuBr, 2-aminopyrimidine-4,6-diol, and TBAF (n-Bu4NF), a variety of imidazoles underwent the N-arylation reaction with aryl and heteroaryl halides smoothly in moderate to excellent yields. Noteworthy is that the reaction is conducted under solvent-free conditions.