Photoinduced difunctionalizations of unactivated olefins enabled by ligand-to-iron charge transfer and functional group migration strategies

Abstract

The difunctionalization of olefins via a radical-mediated functional group migration (FGM) strategy can simultaneously construct two or more chemical bonds, greatly improving the synthesis efficiency of organic molecules. Herein, the 1,2-dicarbofunctionalization of unactivated olefins containing migration groups with fluoroalkyl carboxylic acids or aldehydes have been developed via a photoinduced ligand-to-iron charge transfer strategy, including 1,2-fluoroalkylacylation, fluoroalkylarylation, and acylarylation. (Hetero)aryl, aromatic and aliphatic acyl groups can serve as suitable migration groups, and both aromatic and aliphatic aldehyde substrates can participate in the 1,2-acylarylation as carbon-centered radical precursors. Structurally diverse fluorine-containing alkyl, acyl and (hetero) aryl groups can be introduced into unactivated olefins through this synthetic protocol with excellent site-selectivity. Photoinduced decarboxylation or a hydrogen atom transfer process mediated by Fe(III)–carboxylate complexes or Fe(III)–chlorine complexes, as well as functional group migration, are the core processes of this protocol. The practicality of this method has been demonstrated by a gram-scale reaction and the derivatization of drug molecules such as ibuprofen, camphor, and gemfibrozil.