TfOH-Promoted Decyanative Cyclization toward the Synthesis of 2,1-Benzisoxazoles

Tf2O-Promoted Chemoselective C3 Functionalization of Anthranils with Phenols and Thiophenols

Different chemoselectivities of phenols and thiophenols were observed in a Tf₂O-promoted C3 functionalization of simple anthranils. The reaction of phenols and anthranils gives 3-aryl anthranils via a C-C bond formation, whereas thiophenols afford 3-thio anthranils through a C-S bond formation. Both reactions have a broad substrate scope and tolerate a wide range of functional groups, affording the corresponding products with specific chemoselectivity.

Synthesis of Isoxazoles via One-Pot Oxidation/Cyclization Sequence from Propargylamines

A facile strategy for the synthesis of isoxazoles has been efficaciously developed, which involves oxidation of propargylamines to the corresponding oximes followed by CuCl-mediated intramolecular cyclization of the latter. This protocol shows a straightforward way to construct a series of isoxazole cores with a wide range of functional group compatibility. Meanwhile, a gram-scale experiment and synthetic applications can be successfully operated.

Practical Synthesis of 3-Aryl Anthranils via an Electrophilic Aromatic Substitution Strategy

We report a practical route for the synthesis of valuable 3-aryl anthranils from readily available anthranils and simple arenes by using the classical electrophilic aromatic substitution (EAS) strategy. This transformation goes through an electrophilic substitution and rearomatisation sequence by employing Tf₂O as an effective activator. A wide range of arenes were compatible in this transformation, delivering various structurally diversified 3-aryl anthranils in good yields and high regioselectivity. In addition, a variety of readily available feedstocks such as olefins, alkenyl triflates, silyl enolethers, carbonyl compounds, thiophenols and thiols could also participate in the reaction to achieve the C3 alkenylation, alkylation and thioetherification of anthranils. Of note, the synthesized 3-aryl anthranils proved to be a highly robust platform to access a series of biologically active compounds, drug derivatives and organic optoelectronic materials.

A practical route for the synthesis of valuable 3-aryl anthranils from readily available anthranils and simple arenes has been achieved through an electrophilic substitution and rearomatization sequence by employing Tf₂O as an effective activator.

Construction of a Protoberberine Alkaloid Skeleton via the Palladium-Catalyzed α-Arylation-Amide Formation Cascade

In this work, we report the strategy of one-pot synthesis of protoberberine alkaloid derivatives via palladium-catalyzed cascade α-arylation and cyclization, which can afford the target molecules in moderate to excellent isolated yields using commercially available raw materials under solvent-free conditions. This protocol provides an efficient and convenient path to multisubstituted protoberberine derivatives. In addition, it can directly afford natural alkaloids.