Total Synthesis of the Proposed Structure of Turkiyenine

Synthesis of 3-Benzazepines via Cobalt-Catalyzed C-H Bond Functionalization with CaC2 as the Acetylene Source

Herein, we report a simple method for the synthesis of 3-benzazepine derivatives via a cobalt-catalyzed, picolinamide-directed α-amidoacrylate C(sp2)-H bond functionalization approach. The reactions utilize calcium carbide as an inexpensive, easy-to-handle, and solid acetylene source, and simple CoCl2 as the reaction catalyst. Excellent functional group tolerance is observed, yielding diverse substituted 3-benzazepine derivatives in good to excellent yields.

Discovery of 3CLpro inhibitor of SARS-CoV-2 main protease

Coronavirus main protease (3CLpro), a special cysteine protease in coronavirus family, is highly desirable in the life cycle of coronavirus. Here, molecular docking, ADMET pharmacokinetic profiles and molecular dynamics (MD) simulation were performed to develop specific 3CLpro inhibitor. The results showed that the 137 compounds originated from Chinese herbal have good binding affinity to 3CLpro. Among these, Cleomiscosin C, (+)-Norchelidonine, Protopine, Turkiyenine, Isochelidonine and Mallotucin A possessed prominent drug-likeness properties. Cleomiscosin C and Turkiyenine exhibited excellent pharmacokinetic profiles. Furthermore, the complex of Cleomiscosin C with SARS-CoV-2 main protease presented high stability. The findings in this work indicated that Cleomiscosin C is highly promising as a potential 3CLpro inhibitor, thus facilitating the development of effective drugs for COVID-19.

[3 + 2] Coupling of Quinone Monoacetals with Vinyl Ethers Effected by Tetrabutylammonium Triflate: Regiocontrolled Synthesis of 2-Oxygenated Dihydrobenzofurans

The synthesis of 2-oxygenated dihydrobenzofurans involving the [3 + 2] coupling of quinone monoacetals with vinyl ethers has been realized by tetrabutylammonium triflate catalysis. The reaction involves a new activation method of the acetal moiety in quinone monoacetals under acid-free conditions affording the highly oxygenated dihydrobenzofurans. This new activation mode was achieved by using the triflate anion catalyst for stabilization of the highly reactive cationic intermediate.

Aryne-based strategy in the total synthesis of naturally occurring polycyclic compounds

This review has outlined the strategies and tactics of using arynes in the total syntheses of polycyclic natural products.

Mild Reductive Functionalization of Amides into N-Sulfonylformamidines

The development of a protocol for the reductive functionalization of amides into N‐sulfonylformamidines is reported. The one‐pot procedure is based on a mild catalytic reduction of tertiary amides into the corresponding enamines by the use of Mo(CO)₆ (molybdenum hexacarbonyl) and TMDS (1,1,3,3‐tetramethyldisiloxane). The formed enamines were allowed to react with sulfonyl azides to give the target compounds in moderate to good yields.

Facile preparation of pyrimidinediones and thioacrylamides via reductive functionalization of amides

A protocol for the mild and chemoselective reductive functionalization of amides into pyrimidinediones and thioacrylamides has been developed.

Transition metal-catalyzed iodine(iii)-mediated nitrene transfer reactions: efficient tools for challenging syntheses

The main synthetic applications of catalytic C(sp³)–H amination and alkene aziridination reactions are discussed in the context of natural product synthesis. The examples highlight that these synthetic methods now firmly belong in the organic chemist's toolbox.

Chemoselective reduction of carboxamides

This tutorial review presents the most prominent protocols developed for chemoselective amide reduction.