119th General Meeting of the KCS

Type Symposium
Area [SRC 심포지엄] New Trends and Developments in Organic Synthesis
Room No. 303호
Time WED 16:50-:
Code KCS5-13
Subject Three-Component Synthesis of Quinolines based on Visible-Light Photoredox Catalysis
Authors 최준호, 박철민*
UNIST 화학과, Korea
Abstract

Recently, irradiation of visible light photoredox catalyst has been widely used to drive transformation of organic molecules though the highly desirable processes. Photocatalysts absorb visible light to provide stable, long-lived photo-excited states. The conversion of these excited states to the bench states induces single-electron-transfer events providing access to radical ion intermediates having reactivity patterns fundamentally different from those of their ground electronic or excited states. Multicomponent reactions (MCR) serve as a powerful tool, employing three or more simple building blocks to produce complex molecular frameworks in a single step. Photoredox catalysis has been explored in the context of MCR. However, the limited examples are mostly based on radical-polar crossover mechanisms, in which the process is in operation for initial coupling of two reactants, while a third component is incorporated via a polar process. Although this approach is useful, quenching of radical processes by redox catalysts entailing the involvement of polar processes poses limitations in the scope of coupling partners. To the best of our knowledge, MCR with three consecutive bond formation based on radical processes via visible-light photoredox catalysis has not been reported.Due to their utilities, significant efforts have been made to develop efficient synthetic methods for quinolines. However, the conventional methods rely on condensation under harsh conditions and more recent developments are limited to transitional metal-catalyzed and iodine-mediated synthesis. Here, a successful development of a new tandem radical cyclization based on visible-light photoredox catalysis enables the efficient formation of quinolines based on consecutive radical processes.

E-mail desireholic@unist.ac.kr