Title: Generation of Donor/Donor Copper Carbenes through Copper-Catalyzed Diyne Cyclization: Enantioselective and Divergent Synthesis of Chiral Polycyclic Pyrroles

J. Am. Chem. Soc. 2019, 141, 42, 16961-16970

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.

Published: 26 September 2019

Full Link: https://pubs.acs.org/doi/10.1021/jacs.9b09303