Azoxyarenes are among important scaffolds in organic molecules. Direct oxidative coupling of primary anilines provides a concise fashion to construct them. However, whether these scaffolds can be prepared from secondary N-alkylanilines is not well explored. Here, we present a catalytic selective oxidative coupling of secondary N-alkylaniline to afford azoxyarene with tungsten catalyst under mild conditions. In addition, azoxy can be viewed as a bioisostere of alkene and amide. Several “azoxyarene analogues” of the corresponding bioactive alkenes and amides showed comparable promising anticancer activities.

A general and highly efficient straightforward protocol for the preparation of tetrasubstituted 2,3-allenoates through a palladium-catalyzed coupling reaction of 3-alkoxycarbonyl propargylic carbonates and boronic acids with commercially available tri(o-tolyl)phosphine as a ligand has been developed.

C2, C3-disubstituted indole is one of the most frequently encountered motifs in bioactive alkaloids and medicinal chemistry. Thus, developing novel, concise, and efficient access to it is highly desired in drug discovery. Herein, we present such an approach to this scaffold by direct oxidative coupling of C2-substituted indoles and enolates. Compared with indole bearing no C2-substituent, higher yields (up to 96%) were obtained for C2-substituted indoles in most cases. Mechanistic studies showed the reaction went through a Fe-chelated radical-anion oxidative coupling procedure promoted by C2-substituent on indole by two means: (1) stabilizing C2-radical intermediate during the reaction; (2) reducing indole homocoupling. This approach serves as a synthetic useful tool to quickly build up bioactive small molecule library of C2, C3-disubstituted indoles, and several products showed promising anticancer activities. Besides, indomethacin and its analogs were conveniently prepared in three-step sequence efficiently, indicating the potential application of our approach in medicinal chemistry.

With the readily available Gorlos-Phos as a ligand, unsymmetrical biaryls were prepared efficiently from Pd-catalyzed one-pot two-step cross-coupling of two different aryl chlorides in the presence of B2Pin2.

Desulfitative cross‐coupling of propargylic carbonates with sodium sulfinates has been observed. The reaction exhibited good functional group compatibility affording allenes as a single product. Potential anticancer activities of these allene products were also studied.magnified image