Stable Organic Radicals Derived from N-Heterocyclic Carbenes

Youngsuk Kim; Eunsung Lee

doi:10.1002/chem.201801560

Stable Organic Radicals Derived from N-Heterocyclic Carbenes

Chemistry. 2018 Dec 20;24(72):19110-19121. doi: 10.1002/chem.201801560. Epub 2018 Oct 30.

Authors

Youngsuk Kim^{1

2}, Eunsung Lee^{1

2

3}

Affiliations

¹ Center for Self-assembly and Complexity, Institute for Basic Science (IBS), Pohang, 37673, Republic of Korea.
² Department of Chemistry, Pohang University of Science and Technology, Pohang, 37673, Republic of Korea.
³ Division of Advanced Materials Science, Pohang University of Science and Technology, Pohang, 37673, Republic of Korea.

PMID: 30058298
DOI: 10.1002/chem.201801560

Abstract

Over the past decade, numerous stable organic and main-group radicals have been synthesized from N-heterocyclic carbenes (NHCs). The structure of NHCs, in particular, offers electronic stabilization that helps to delocalize the unpaired electron over the molecule. In addition, the sterically bulky substituents of NHCs protect the radical center to prevent detrimental reactions such as dimerization. These advantages enable the straightforward synthesis and characterization of various interesting organic radicals starting from NHCs, which are, these days, widely available. NHCs have enabled the structural characterization of various organic radicals over the past decade, including α-carbonyl, propargyl, oxyallyl, and triazenyl radicals as notable examples. This minireview summarizes the advances in this field, mainly focusing on the preparation and stability as well as the properties and applications of NHC-derived organic radicals.

Keywords: carbenes; radicals; redox chemistry; stabilization; transient species.

Publication types

Review