Visible-light-mediated interrupted Cloke-Wilson rearrangement of cyclopropyl ketones to construct oxy-bridged macrocyclic framework

oleh: Zhen Liu, Yin Wei, Min Shi

Format: Article
Diterbitkan: Elsevier 2022-03-01

Deskripsi

Cloke-Wilson rearrangement has been well studied, in which cyclopropyl ketones or cyclopropyl imines could be transformed to dihydrofuran or dihydropyrrole derivatives through a tandem ring-opening/recyclization process. Herein, we report a new version of Cloke-Wilson rearrangement, in which the ring-opening/recyclization of cyclopropyl ketones upon visible-light-induced photoredox catalysis can provide oxy-bridged macrocyclic frameworks under mild reaction conditions, and the reagent XRf plays dual roles in the catalytic cycle. The reaction proceeds through a ring-opening and an interrupted recyclization by intramolecular nucleophilic attack with the in situ generated radical cation. The reaction mechanism was proposed on the basis of control, deuterium labeling, Stern–Volmer quenching and CV measuring experiments. This protocol can afford a series of oxy-bridged macrocyclic frameworks with broad substrate scope and good functional-group tolerance. In addition, a variety of 2,2-disubstituted oxy-bridged macrocyclic indolinones can be obtained efficiently by simple manipulation from the products.