Palladium(II)-Catalyzed Mono- and Bis-alkenylation of N-Acetyl-2-aminobiaryls through Regioselective C-H Bond Activation

Electrochemical Annulation of p-Alkoxy or p-Hydroxy Anilines with Enaminones for Selective Indole and Benzofuran Synthesis

The green and sustainable electrochemical oxidative cyclization of enaminones with p-methoxy/p-hydroxy anilines has been developed, enabling the regioselective synthesis of indoles and benzofurans. The methods are of significant advantage not only due to the mild and metal-free sustainable electrochemical conditions, but also because of the employment of easily available and stable aniline substrates to replace the unstable quinoneimide for a similar annulation in previous work.

Controllable Synthesis of Benzo[b]furo[2,3-d]azepines or Furo[3,2-b]indoles via Intermolecular Oxidative Annulation of 2-(Furan-2-yl)anilines and Propargyl Carbonates versus Intramolecular C-H Amination Reactions

Two novel Pd-catalyzed protocols for the controllable synthesis of benzo[b]furo[2,3-d]azepines and furo[3,2-b]indoles have been developed by intermolecular oxidative annulation of 2-(furan-2-yl)anilines and propargyl carbonates versus intramolecular C-H amination reactions. These two protocols feature great scalability, functional group tolerance, and relatively mild reaction conditions. Notably, the robust methodologies could also provide valuable opportunities for assembling azepine-fused benzothiophene, indole-fused benzothiophene, and indole-fused benzimidazole, which may have potential applications in the synthesis of related pharmaceuticals or polymeric materials.

Ligand-free Pd-catalyzed highly selective arylation of activated and unactivated alkenes via oxidative and reductive heck coupling

In this work, an eco-friendly, green, efficient approach for oxidative and reductive Heck-Mizoroki (HM) reactions was developed, which offered acceptable yields from first-pass experiments. Mono-arylation was achieved without the use of ligands, directing groups, or prefunctionalized alkenes. Considering mild reaction conditions, good functional group compatibility, and great regioselectivity, the method can find broad applications in novel medicine and material development and discovery processes.

Distal-C-H Functionalization of Biphenyl Scaffolds Assisted by Easily Removable/Recyclable Aliphatic Nitrile Templates

We present here the distal-C-H activation/functionalization of biphenyl scaffolds using aliphatic nitrile templates. The approach has demonstrated good to exclusive meta selectivities over a wide range of olefination and acetoxylation substrates. In addition, bis-olefination has been accomplished in a one-pot, sequential manner. Notably, this technique highlights the diversification of pharmaceuticals and natural products. Consequently, the temporary directing aliphatic template has been recovered quantitively from the coupled product.

Sodium Trifluoroacetate mediated Copper-Catalyzed aza-Michael addition of α,β-unsaturated olefins with aromatic amines

We present a sodium trifluoroacetate (CF3CO2Na) mediated copper-catalyzed aza-Michael addition of aromatic amines with activated olefins under mild, aqueous reaction conditions. This simplistic protocol employs a copper catalyst (10 mol%) and water as solvent. This transformation occurs precisely with aromatic substituted amines containing both electron-donating (EDG) and electron-withdrawing (EWG) groups. A broad range of substrates were tested under the optimized conditions, which are producing good to moderate yields.

Combined Dynamic Kinetic Resolution and C-H Functionalization for Facile Synthesis of Non-Biaryl-Atropisomer-Type Axially Chiral Organosilanes

Although asymmetric C-H functionalization has been available for the synthesis of structurally diverse molecules, catalytic dynamic kinetic resolution (DKR) approaches to change racemic stereogenic axes remain synthetic challenges in this field. Here, a concise palladium-catalyzed DKR was combined with C-H functionalization involving olefination and alkynylation for the highly efficient synthesis of non-biaryl-atropisomer-type (NBA) axially chiral oragnosilanes. The chemistry proceeded through two different and distinct DKR: first, an atroposelective C-H olefination or alkynylation produced axially chiral vinylsilanes or alkynylsilanes as a new family of non-biaryl atropisomers (NBA), and second, the extension of this DKR strategy to twofold o,o'-C-H functionalization led to the multifunctional axially chiral organosilicon compounds with up to >99 % ee.

Palladium-catalysed Heck-type alkenylation reactions in the synthesis of quinolines. Mechanistic insights and recent applications

Recent developments in Pd(0)- and Pd(ii)-catalysed alkenylation reactions for the synthesis of quinolines focusing on mechanistic understanding.

PdCl2(CH3CN)2-catalyzed regioselective C-H olefinations of 2-amino biaryls with vinylsilanes as unactivated alkenes

The first example of palladium-catalyzed chelation-assisted C-H olefination of 2-amino biaryls using readily available vinylsilanes as unactivated olefinating reagents has been developed, affording valuable arylated vinylsilane compounds in moderate to excellent yields and with exclusive (E)-selectivities.