Authors: Feng-Lin Hong, Ze-Shu Wang, Dong-Dong Wei, Tong-Yi Zhai, Guo-Cheng Deng, Long-Wu Ye
Abstract:
The generation of metal carbenes from readily available alkynes represents a significant advance in metal carbene chemistry. However, most of these transformations are based on the use of noble-metal catalysts and successful examples of such an asymmetric version are still very scarce. Here a copper-catalyzed enantioselective cascade cyclization of N-propargyl ynamides is reported, enabling the practical and atom-economical construction of diverse chiral polycyclic pyrroles in generally good to excellent yields with wide substrate scope and excellent enantioselectivities (up to 97:3 e.r.). Importantly, this protocol represents the first copper-catalyzed asymmetric diyne cyclization. Moreover, mechanistic studies revealed that the generation of donor/donor copper carbenes is presumably involved in this 1,5-diyne cyclization, which is distinctively different from the related gold catalysis, and thus it constitutes a novel way for the generation of donor/donor metal carbenes.
Source: https://chem.xmu.edu.cn/en/info/1021/1748.htm
Full Link: https://pubs.acs.org/doi/10.1021/jacs.9b09303
