symmetric Organocatalyzed Cyclization Cascade Reactions of 3,3-Difluoro-2-aryl-3H-indoles an Enamides

By: Xiu-Xiu Qia, Shi-Na Zhao, Qian Li, Tao Ma, Ganpeng Li, Yonghui He, Xiao-Jing Zhao

DOI: https://doi.org/10.1021/acs.orglett.3c04162

Published：2024-02-07

Abstract

The direct functionalization of β-C(sp²)-H bonds in enamides has garnered increasing attention within the realm of organic synthesis. However, these remarkable advancements are predominantly dependent on transition metals; limited success has been achieved via organocatalytic catalysis. Herein, we report a CPA-catalyzed β-C(sp²)-H functionalization of enamides cascade intramolecular cyclization to synthesize the chiral dihydropyrimido[1,6-a]indoles bearing gem-difluoromethylene. Moreover, this methodology enables the synthesis of diverse chiral dihydropyrimido[1,6-a]indoles with outstanding enantioselectivities in moderate to high yields.