Radical Addition to Iminium Ions and Cationic Heterocycles

Molecules

Johannes Tauber²  Dennis Imbri²  Till Opatz¹ 

[1] id="af1-molecules-19-16190">Institute of Organic Chemistry, Johannes Gutenberg-University Mainz, Duesbergweg 10–14, 55128 Mainz, Germa

关键词: radicals;    iminium salts;    heterocycles;    addition reactions;    rearrangements;    Minisci reaction;    Porta reaction;    photoredox catalysis;    transition metal catalysis;    late-stage functionalization;   

DOI  :  10.3390/molecules191016190

来源: mdpi

【 摘 要 】

Carbon-centered radicals represent highly useful reactive intermediates in organic synthesis. Their nucleophilic character is reflected by fast additions to electron deficient C=X double bonds as present in iminium ions or cationic heterocycles. This review covers diverse reactions of preformed or in situ-generated cationic substrates with various types of C-radicals, including alkyl, alkoxyalkyl, trifluoromethyl, aryl, acyl, carbamoyl, and alkoxycarbonyl species. Despite its high reactivity, the strong interaction of the radical’s SOMO with the LUMO of the cation frequently results in a high regioselectivity. Intra- and intermolecular processes such as the Minisci reaction, the Porta reaction, and the Knabe rearrangement will be discussed along with transition metal and photoredox catalysis or electrochemical methods to generate the odd-electron species.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.