Pinhua Li

Direct Access to Acylated Azobenzenes via Pd-Catalyzed C–H Functionalization and Further Transformation into an Indazole Backbone

Azobenzenes were readily acylated at the 2-position through a Pd-catalyzed C-H functionalization from simple aromatic azo compounds and aldehydes in good yields. The obtained acylated azobenzenes could be efficiently converted into the corresponding indazole derivatives in nearly quantitative yields.

Indium-catalyzed highly efficient three-component coupling of aldehyde, alkyne, and amine via C-H bond activation.

In this paper, indium(III) chloride was found to be a highly effective catalyst for the three-component coupling reactions of aldehydes, alkynes, and amines (A(3)-coupling) via C-H activation. The reactions could be applied to both aromatic and aliphatic aldehydes and alkynes. Nearly quantitative yields of the desired products were obtained in most cases. No cocatalyst or activator is required, and water is the only byproduct in the reactions. Furthermore, a tentative mechanism of the InCl(3)-catalyzed one-pot, three-component coupling of aldehyde, alkyne, and amine is proposed.

Iron‐Catalyzed Ligand‐Free Three‐Component Coupling Reactions of Aldehydes, Terminal Alkynes, and Amines

A tri-umph in many respects: The iron-catalyzed ligand-free, one-pot three-component coupling reactions of aldehydes, terminal alkynes, and amines in the presence of 4 A molecular sieves yields the corresponding propargylamines in good to excellent yields, displays a broad substrate scope, and is economical and environmentally friendly (see scheme).

Copper-promoted decarboxylative direct C3-acylation of N-substituted indoles with α-oxocarboxylic acids

A novel and efficient Cu-promoted decarboxylative direct C3-acylation of N-substituted indoles with α-oxocarboxylic acids for the synthesis of 3-acylindoles was developed.

Sequential and One-Pot Reactions of Phenols with Bromoalkynes for the Synthesis of (Z)-2-Bromovinyl Phenyl Ethers and Benzo[b]furans

Benzo[b]furans were prepared in one pot based on the addition/palladium-catalyzed C-H bond functionalization of phenols with bromoalkynes. The addition reactions of phenols to bromoalkynes generated (Z)-2-bromovinyl phenyl ethers in high yields with excellent regio- and stereoselectivity. The obtained (Z)-2-bromovinyl phenyl ethers subsequently proceeded by intramolecular cyclization to afford 2-substituted benzo[b]furans in good yields through palladium-catalyzed direct C-H bond functionalizations. It is important to note that the transformation of phenols with bromoalkynes into benzo[b]furans could be carried out in one pot with a simple and efficient tandem procedure.

A Highly Efficient Palladium‐Catalyzed Decarboxylative ortho‐Acylation of Azobenzenes with α‐Oxocarboxylic Acids: Direct Access to Acylated Azo Compounds

Avoiding additives: A highly efficient and mild Pd-catalyzed decarboxylative ortho-acylation of azobenzenes with α-oxocarboxylic acids was developed that provides an alternative route to acylated azo compounds. This decarboxylative acylation process was completed in the absence of any additives at ambient temperature, to afford the acylated azobenzenes in moderate to good yields.

Iron-Promoted Tandem Reaction of Anilines with Styrene Oxides via C–C Cleavage for the Synthesis of Quinolines

A novel iron-promoted tandem reaction of anilines with styrene oxides via C-C cleavage and C-H activation has been developed. The reaction utilizes an inexpensive FeCl(3) as promoter and is suitable for forming a variety of 3-arylquinolines from the simple and readily available starting materials.

Palladium-catalyzed deamidative arylation of azoles with arylamides through a tandem decarbonylation-C-H functionalization.

A highly chemo-, regio-selective, and efficient palladium-catalyzed deamidative arylation of azoles with arylamides, as an aryl metal equivalent, has been developed. The reaction proceeds smoothly to generate the corresponding products in good yields via a tandem decarbonylation-C-H activation.

Merging Photoredox with Palladium Catalysis: Decarboxylative ortho-Acylation of Acetanilides with α-Oxocarboxylic Acids under Mild Reaction Conditions

A room temperature decarboxylative ortho-acylation of acetanilides with α-oxocarboxylic acids has been developed via a novel Eosin Y with Pd dual catalytic system. This dual catalytic reaction shows a broad substrate scope and good functional group tolerance, and an array of ortho-acylacetanilides can be afforded in high yields under mild conditions.

Visible-Light Photoredox Catalysis: Direct Synthesis of Sulfonated Oxindoles from N-Arylacrylamides and Arylsulfinic Acids by Means of a Cascade C-S/C-C Formation Process.

A novel photocatalytic synthesis of sulfonated oxindoles from N-arylacrylamides and arylsulfinic acids was developed by means of a cascade C-S/C-C bond-formation process. This method provides mild, efficient, and atom-economical access to various sulfonated oxindoles in water.