Synthesis of Cyclic Compounds via Photoinduced Radical Cyclization Cascade of C=C bonds

Abstract

Cyclic compounds constitute a great important class of substances in the science of medicine and biology, which renders the research on facile and efficient construction of such complex scaffolds from simple starting materials to be hot and appealing. Recently, the radical cascade reaction involving multiple bond formation/cleavage has emerged as an ideal and powerful route to give high-value cyclic products, along with diminished cost and waste. As a simple and benign methodology, photoredox catalysis offers a readily available access to the generation of radical species. Alkenes have been recognized as one of the most valuable building blocks for the reason they allow installation of different functional groups simultaneously through addition to the C=C bonds. This account summarizes the recent advances in photoinduced radical cascade cyclization to the synthesis of cyclic compounds with C=C bonds working as the initial radical acceptors, and emphasis is put on the related reaction mechanisms.

New Strategies for the Synthesis of Aliphatic Azides

“…The cyclization of 1, n -enynes has attracted significant attention in synthetic chemistry because of their utility for the atom- and step-economic construction of a variety of complicated carbo- and heterocyclic frameworks . In particular, azide radical-initiated cyclization of 1, n -enynes has recently been developed as a promising strategy for the synthesis of complex alkyl azides.…”

Stereoselective intermolecular radical cascade reactions of tryptophans or ɤ-alkenyl-α-amino acids with acrylamides via photoredox catalysis

“…In recent years, photocatalysis using visible light has emerged as a promising strategy for the development of novel radical reactions due to its high efficiency and convenience in the generation of various reactive radical species under mild and environmentally friendly conditions 12 – 19 . Specifically, the visible-light-induced radical cascade reactions enable the facile construction of diverse cyclic compounds under sustainable conditions 3 , 20 , 21 . Despite these advances, plenty of radical cascade cyclization reactions still rely on either the carefully designed precursors or the intramolecular design, which tempers the appeal of their further synthetic applications.…”

Advances in Asymmetric Amino Acid Synthesis Enabled by Radical Chemistry

“…[60][61][62][63][64][65][66] Moreover, owing to the generally mild reaction conditions and often high functional group tolerance, radical chemistry represents a well-suited strategy for chemoselective modifications of peptides and proteins. [61][62][63][64][65][66] In general, radical approach [67][68][69][70][71][72] is widely applied in the field of organic synthesis for the rapid construction of complex molecular architectures [73][74][75] and the total synthesis of natural products under safe and mild conditions. [76][77][78][79][80][81] Even in nature many of oxidation processes catalyzed by heme proteins and metalloporphyrins have proceeded through a radical mechanism.…”