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An efficient electrochemical C(sp3)–H arylation of xanthenes using a carbon anode and platinum cathode as the electrodes is disclosed.

A copper-catalyzed C–H [3 + 2] annulation of N-substituted anilines with α-carbonyl alkyl bromides for the synthesis of 3,3′-disubstituted oxindoles is developed. Tandem C–H cycloamidation reactions of various α-carbonyl alkyl bromide derivatives including tertiary-α-bromoalkyl ketone esters, malonic esters and cycloalkanes, with N-aryl or alkyl substituted anilines, can be performed using this system, affording a vast array of valuable 3,3′-disubstituted oxindoles in moderate to good yields.

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. By employing the NiI2 and Ag2CO3 catalytic systems, the method features broad substrate scope with respect to carboxylic acids, including linear alkyl acids, cyclic acids, aryl acids and amino acids.

A copper-catalyzed C-H [3 + 2] annulation of N-substituted anilines with α-carbonyl alkyl bromides for the synthesis of 3,3'-disubstituted oxindoles is developed. Tandem C-H cycloamidation reactions of various α-carbonyl alkyl bromide derivatives including tertiary-α-bromoalkyl ketone esters, malonic esters and cycloalkanes, with N-aryl or alkyl substituted anilines, can be performed using this system, affording a vast array of valuable 3,3'-disubstituted oxindoles in moderate to good yields.

A new copper-catalyzed intermolecular 1,2-aminoalkylation of alkenes with α-bromoalkyl esters and amines for the synthesis of γ-amino esters is described. Employing the Cu(OTf)2 and 2,2′-bipyridine catalytic system, the three-component reaction allows the formation of two new chemical bonds, including one C–C bond and one C–N bond, in a single reaction, and represents a new alkene difunctionalization using a radical strategy.

We here describe a new copper-catalyzed tandem annulation of alkenes with α-bromoalkyl esters and primary amines for producing polysubstituted pyrrolidin-2-ones. The reaction allows the formation of three new chemical bonds, one C-C bond and two C-N bonds, in a single reaction, and represents the first three-component difunctionalization of alkenes for the synthesis of pyrrolidin-2-ones involving [2+2+1] annulation.

A new, radical-mediated, divergent bicyclization of 1, n-enynes by alpha-C(sp(3))-H oxidative functionalization of alkyl nitriles is described using the Sc(OTf)(3) and Ag2O system. The reaction allows the selective functionalization of one or two C(sp(3))@H bonds a to the nitrile group by both oxidants and the substitution effect co-controlled the divergent bicy-clization reactions, and offers a step-and atom-economical access to diverse polycycles with broad substrate scope and high selectivity.

We cover the achievements and thought process that have emerged as a result of the recent use of iron salts as catalysts for the oxidative coupling, addition, and functionalization on constructing C−C bonds, C−N bonds, C−O bonds, C−S bonds, and C−P bonds. These transformations concomitantly require a stoichiometric oxidant to activate the catalyst: The low-cost and ubiquity of peroxides is often used as a result of their high oxidative reactivity, resulting in the widespread utilizations of iron catalysis through the initiation of radical processes. Here, we summarize the formation of diverse chemical bonds by using iron oxidative catalysis strategies, including 1) the oxidative coupling strategy and 2) the oxidative addition and functionalization strategy. The oxidative coupling strategy focuses on the formation of one chemical bond in a single reaction, whereas the oxidative addition and functionalization strategy includes the transformations that construct at least two chemical bonds.

A new silver-promoted oxidative ring opening/alkynylation of cyclopropanols with ethynylbenziodoxolones (EBX) is described. This method enables the formation of alkylated alkynes via a sequence of ring opening and alkynylation. Control experiments support a radical mechanism in this silver-promoted method.

A new 1,4-diazabicyclo[2.2.2]octane (DABCO) mediated synthesis of malonates from 3-halopropynoates, alcohols, and water is presented. This method proceeds under mild and metal-free conditions, and represents a new straightforward access to 1,3-dicarbonyl compounds.

A novel Lewis acid catalyzed annulation reaction has been established for the synthesis of benzocyclohepta[b]indoles. This method represents a new annulation strategy to a seven-membered carbocyclic ring system from two 3-(1H-isochromen-1-yl)-1H-indole molecules using Cu(OTf)2 catalyst; moreover, the products, benzocyclohepta[b]indoles, can be used as the rapid mercuric ion colorimetric detection reagents.

A new, simple, base-mediated addition reaction of 1,2-bis(phenylsulfonyl)ethane to ketones has been developed for the synthesis of 1-aryl-4-(phenylsulfonyl)butan-1-ones. This method represents the first example of preparing sulfones using 1,2-bis(phenylsulfonyl)ethane as the sulfone resource.

An efficient copper-catalyzed α-aminoxylation of ketones with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) is presented.The copper on iron catalyst can be recovered and reused several times with high catalytic reactivity.

Copper-catalyzed amidation of acids with formamides or acetamide for the selective synthesis of amides with the aid of 1,4-diazabicyclo[2.2.2]octane as the ligand and tert-butyl hydroperoxide as the oxidant is presented. This method is highly compatible with a wide range of acids, including alkyl acids, aryl acids, α,β-unsaturated acids, and amino acids.

We cover the achievements and thought process that have emerged as a result of the recent use of iron salts as catalysts for the oxidative coupling, addition, and functionalization on constructing C−C bonds, C−N bonds, C−O bonds, C−S bonds, and C−P bonds. These transformations concomitantly require a stoichiometric oxidant to activate the catalyst: The low-cost and ubiquity of peroxides is often used as a result of their high oxidative reactivity, resulting in the widespread utilizations of iron catalysis through the initiation of radical processes. Here, we summarize the formation of diverse chemical bonds by using iron oxidative catalysis strategies, including 1) the oxidative coupling strategy and 2) the oxidative addition and functionalization strategy. The oxidative coupling strategy focuses on the formation of one chemical bond in a single reaction, whereas the oxidative addition and functionalization strategy includes the transformations that construct at least two chemical bonds.

A new silver-promoted oxidative ring opening/alkynylation of cyclopropanols with ethynylbenziodoxolones (EBX) is described. This method enables the formation of alkylated alkynes via a sequence of ring opening and alkynylation. Control experiments support a radical mechanism in this silver-promoted method.

A new 1,4-diazabicyclo[2.2.2]octane (DABCO) mediated synthesis of malonates from 3-halopropynoates, alcohols, and water is presented. This method proceeds under mild and metal-free conditions, and represents a new straightforward access to 1,3-dicarbonyl compounds.

Open a new door: The first example of alkene synthesis from alkyl electrophiles with Grignard reagents using the Kumada cross-coupling reaction strategy is reported. This method opens a new door for the Kumada cross-coupling reaction, allowing alkenes to be prepared from the reaction of tosylalkanes with Grignard reagents.

A new, practical, base-mediated method has been developed for the synthesis of 2,4-bis(aryloxy)-1,5-diarylpentane-1,5-diones by a tandem α-methylenation–Michael reaction through activation of two C–Cl bonds. This method permits the use of dichloromethane instead of dibromomethane as a source of one carbon atom for the α-methylenation reaction. The products are useful in syntheses of polysubstituted pyridines and methylenebisbenzofurans.

A novel palladium-catalyzed CH oxidation of isoquinoline N-oxides has been developed for regioselectively synthesizing substituted isoquinolines. The method represents the first example of using dialkyl sulfoxides as the alkyl sources for the construction of 1-alkylated isoquinolines. Moreover, the regioselective halogenation of isoquinoline N-oxides is also successful using dihalo sulfoxides as the halide sources.

A novel gold-catalyzed skeletal rearrangement of 1-[2-(1 H -isochromen-3-yl)aryl]ethanones with alcohols to construct a five-membered carbocycle ring onto aromatic systems has been developed. This method serves as the first example of synthesizing inden-1-ones by a gold-catalyzed skeletal rearrangement strategy.

A new, general method for the synthesis of spiro[4,5]trienones is described by the intramolecular ipso-halocyclization of 4-(p-unsubstituted-aryl)-1-alkynes. In the presence of halide electrophiles, a variety of 4-(p-unsubstituted-aryl)-1-alkynes underwent the intramolecular ipso-halocyclization with water smoothly, affording the corresponding halo-substituted spiro[4,5]trienones in moderate to good yields. The obtained spiro[4,5]trienones can be applied in constructing the azaquaternary tricyclic skeleton via Pd-catalyzed Heck reaction. Notably, the prepared spiro[4,5]trienones and azaquaternary tricycles are of importance in the areas of pharmaceuticals and agrochemicals. The mechanism of the intramolecular ipso-halocyclization reaction is also discussed according to the (18)O-labeling experiments and DFT calculations.

A new, general method for the synthesis of phenanthridines has been developed by palladium-catalyzed oxidative remote CH olefination–carboamination–CC bond cleavage tandem reaction. It is noteworthy that alkenes are used as the one-carbon resources for this tandem reaction.

Ligand-free palladium-catalyzed Suzuki-Miyaura cross-coupling of iodoethynes with arylboronic acids under aerobic conditions has been developed. In the presence of palladium(II) acetate and cesium carbonate, a variety of iodoethynes underwent the Suzuki-Miyaura cross-coupling reaction with arylboronic acids at room temperature to afford the corresponding internal alkynes in moderate to good yields. It is noteworthy that this protocol proceeds under mild and aerobic conditions without the aid of ligands.

The first example of the synthesis of 4,5-disubstiuted furan-2(5H)-ones by base-mediated tandem acyl shift/cyclization/decarbonylation reactions of aroylmethyl 2-alkynoates has been developed. This new and inexpensive tandem route allows both a C―O bond and a Csp 3 ―Csp 2 bond forming in one step involving an unprecedented acyl rearrangement process.

An iron-mediated tandem annulation strategy has been developed for the synthesis of numerous functional indeno[1,2-c]chromenes and 5H-naphtho[1,2-c]chromenes. This work is the first to disclose an iron-mediated method through sequential electrophilic addition of a ketone to an alkyne and annulation tandem reaction. Importantly, a halide is introduced into the products by a ring-opening process among the annulation of alkynylcyclopropanes, which makes the methodology more attractive for organic synthesis.

Synthesis of alkyl aryl ethers via copper-catalyzed etherizations of electron-deficient aryl fluorides with quaternary ammonium bromides and water has been developed. In the presence of Cu(OAc)2, POPh3 (L4) and Cs2CO3, a variety of electron-deficient aryl fluorides underwent the reaction with quaternary ammonium bromides and H2O in moderate to good yields. The mechanism was also discussed.

Carbon dioxide as both a selective agent and reaction media in the palladium-catalyzed Ullmann-type coupling has been described. The results showed that aryl chlorides could be easily activated in the presence of carbon dioxide and the chemoselectivity shifted toward the palladium-catalyzed Ullmann-type coupling reaction. In liquid carbon dioxide, homocoupling reactions of aryl halides, including less reactive aryl chlorides, were carried out smoothly in moderate to good yields using Pd/C, zinc, and H2O as the catalytic system at room temperature.

In water, ammonium chloride was found to promote palladium-catalyzed Ullmann coupling reactions of aryl bromides. In the presence of Pd/C, zinc, NH4Cl, and water, coupling of various aryl bromides was carried out smoothly to afford the corresponding homocoupling products in moderate yields.

Palladium-catalyzed cross-coupling reaction of terminal alkynes with arylboronic acids has been described. In the presence of Pd(OAc)(2) and Ag(2)O, a variety of terminal alkynes, including electron-poor terminal alkynes, smoothly underwent the reaction with numerous boronic acids to afford the corresponding internal alkynes in moderate to good yields. Moreover, this methodology was applied to the synthesis of 1H-isochromenes and diynes. It is noteworthy that the reaction proceeds under ligand-free and relative lower loading Pd conditions, and the maximal TONs (turnover numbers) of the reaction are up to 720,000.

A novel method for the synthesis of 9-aryl-3a,4-dihydronaphtho[2,3- C]furan-1(3 H)-oneshas been developed by P 4 - T-Bu-catalyzedintramolecular cascade reactions of enynes. In the presence of acatalytic amount of phosphazene P 4 - T-Bubase, a variety of 3-arylallyl 3-arylpropiolates underwent the cascadecyclization reaction smoothly in moderate to excellent yields.

Ligand-free and reusable palladium-catalyzed Suzuki-Miyaura cross-coupling reaction performed in TBAB (tetra-n-butylammonium bromide) was presented. It was found that the amount of water affected these reactions. Excellent results were obtained when there was w=1% of water in TBAB. In the presence of 3 mol% of Pd(OAc)2 and 1.5 g of TBAB (containing w=1% of water), a number of aryl halides were coupled with arylboronic acids smoothly in moderate to excellent yields. Moreover, the Pd(OAc)2/TBAB system among the couplings of aryl bromides and activated chlorides could be recovered and reused three times without a loss of catalytic efficiency.

A solvent-free copper/iron-catalyzed N-arylation of nitrogen-containing heterocycles with trimethoxysilanes method for the formation of C–N bonds has been developed. In the presence of Cu, FeCl3, TBAF, and air, a variety of nitrogen-containing heterocycles including imidazoles and triazoles were coupled with aryltrimethoxysilanes and vinyltrimethoxysilane to afford the corresponding products in moderate to excellent yields. It is noteworthy that the reaction is conducted under solvent-free and relatively low Cu/FeCl3 loadings conditions.

β-Oxo amides were found to be inexpensive and efficient ligands for the palladium-catalyzed Suzuki-Miyaura cross-coupling reaction. In the presence of palladium(II) acetate and N-(4-methoxyphenyl)-3-oxobutanamide ( L7), a variety of aryl halides, including deactivated aryl chlorides and heteroaryl halides, were successfully coupled to arylboronic acids in moderate to excellent yields providing very high turnover numbers (maximum TON

An efficient and reusable Cu2O/PPh3/TBAB (n-Bu4NBr) system for the cross-coupling reactions of aryl and heteroaryl halides with terminal alkynes has been developed. Four types of Cu2O, including bulky Cu2O, cubic Cu2O nanoparticles, octahedral Cu2O nanoparticles, and spherical Cu2O nanoparticles, were examined, and the octahedral Cu2O nanoparticles were found to be the most effective catalyst for the reaction. In the presence of the octahedral Cu2O nanoparticles, PPh3, and TBAB, a variety of aryl and heteroaryl halides were reacted with alkynes including alkynols smoothly in moderate to good yields. Noteworthy is that the Cu2O/PPh3/TBAB system can be recovered and reused several times without loss of any activities.

Pd(MeCN)2Cl2/PCy3 was found to be an efficient catalytic system for the Suzuki–Miyaura cross‐couplings of aryl chlorides with arylboronic acids under solvent‐free conditions. Furthermore, the presence of the conventional solvents had deleterious effect on the reaction. In the presence of Pd(MeCN)2Cl2, PCy3, and TBAF (tetra‐n‐butylammonium fluoride), a number of aryl chlorides including heteroaryl chlorides were coupled with arylboronic acids or heteroarylboronic acids smoothly to afford the corresponding products in moderate to excellent yields.