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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.

A practical method is developed for the synthesis of oxazolidinone derivatives, an important class of heterocyclic compounds. The effect of bases and solvents on this cyclization reaction is discussed and a simple new base–solvent system (triethylamine in toluene) is found to be the most effective. The reaction conditions developed here are mild and no by-products are observed. Moreover, using optimized conditions, a number of differently substituted propargylic alcohols are cyclized to the corresponding N-substituted-4-methylene-oxazolidinones in yields of up to 99%.

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.

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.

Lemonile is a new kind of spice. The new technology for synthesis of lemonile from citral by catalytic ammoxidation has been investigated. Experimental results showed the optimal synthetic conditions are as follows. The molar material ratio n(H2O2):n(Citral) is 3:1, solvent for the reaction is isopropanol, dosage of the catalyst CuCl is 3% (wt, calculated by citral), the drop-feeding temperature and time for hydrogen peroxide are 10 °C-14 °C and 3 hrs, respectively; after hydrogen peroxide being drop-fed into the reaction system, the reaction should be continued for 4 hrs. Lemonile yield is 91.2% and purity is 98.5% (detected by GC) under the optimal conditions. This new one-step liquid phase catalytic ammoxidation technology is a green synthesis way for lemonile. The structure of the product has been confirmed by GC-MS.

The title reaction offers a mild and efficient method for the synthesis of 6H-benzo[c]chromenes.

The substitution pattern at the indan products depends on the phosphine ligand in conditions A) or B).

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.

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

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−sp2 and sp2−sp3 couplings of allylic alkynoates with arynes in one pot involving a decarboxylation 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.

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.

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.

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.

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.

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.

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.

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.

Excellent results have been achieved in the Cu(OAc)2-catalyzed Sonogashira cross-couplings of aryl iodides and activated aryl bromides utilizing TBAF (tetrabutylammonium fluoride) as the base and 4,6-dimethoxypyrimidin-2-amine as the ligand. It is noteworthy that the reaction is conducted under aerobic, solvent-free and palladium-free conditions.

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.