Recent Advances for the Construction of Seven-Membered Ring Catalyzed by N-Heterocyclic Carbenes

The seven-membered rings represent an important structural motif and have found wide presence in natural products, biologically active molecules and drugs. In contrast to the five- and six-membered rings, the construction of seven-membered ring remains challenging. Thus, the developing efficient strategies for the synthesis of seven-membered rings is very desirable. N-Heterocyclic carbene (NHC) organocatalysis has been recognized as a powerful and unique tool for the quick construction of complex molecular architectures. Nevertheless, whereas significant advances have been made using NHC as catalysis. However, most of these works concentrated on the assembly of five or six-membered rings. This review highlights the developments and new advances for the construction of seven-membered rings catalyzed by NHC. The aim of this review is to provide an overview of this area and inspire synthetic chemists to develop more efficient and novel strategies for the construction of seven-membered rings.

Automated summary

Seven-membered rings are important in chemistry and pose a challenge for synthetic chemists. N-Heterocyclic carbene (NHC) organocatalysis is a powerful tool for quick construction of complex molecular structures, and this review highlights new advances in the synthesis of seven-membered rings catalyzed by NHC.