Visible-Light-Induced Dearomatization of Indoles/Pyrroles with Vinylcyclopropanes: Expedient Synthesis of Structurally Diverse Polycyclic Indolines/Pyrrolines

Autor: Xu-Lun Huang, Chao Zheng, Shu-Li You, Shuo Sun, Min Zhu
Rok vydání: 2021
Předmět:
Zdroj: Journal of the American Chemical Society. 143:13441-13449
ISSN: 1520-5126
0002-7863
DOI: 10.1021/jacs.1c07082
Popis: Visible-light-induced cycloaddition reactions initiated via energy-transfer processes have recently evolved as powerful methods for the construction of strained cyclic molecules that are not easily accessed using known ground-state synthetic methods. Particularly, the reactions initiated by the excitation of aromatic rings provide an alternative solution to the direct transformations of aromatic feedstocks under the scheme of dearomatization. Vinylcyclopropanes (VCPs) are well-known reagents in radical clock experiments, working as a probe to detect transient radical intermediates. However, the synthetic applications in this regard still remain limited due to uncontrollable selectivities. Herein, we report visible-light-induced dearomatization of indole- or pyrrole-tethered VCPs, in which several competitive reaction pathways, including [5 + 2], [2 + 2], interrupted [5 + 2], and [5 + 4] cycloadditions, can be well regulated by engineering substrate structures and tuning reaction conditions. The reaction mechanism has been explored by combined experimental and computational investigations. These reactions provide a convenient method to synthesize structurally diverse polycyclic molecules with high efficiency and good selectivity.
Databáze: OpenAIRE