CO Fixation to Stable Acyclic and Cyclic Alkyl Amino Carbenes: Stable Amino Ketenes with a Small HOMO–LUMO Gap

Abstract

A quick fix: In contrast to cyclic diamino carbenes, stable alkyl amino carbenes react with CO to give stable ketenes (see scheme, top). Contrary to the acyclic versions, cyclic amino ketenes cannot escape from the destabilizing n–π donation of the nitrogen lone pair, which induces a diradical character and unusual optical (see scheme, bottom and photographs of crystals) and NMR spectroscopic properties. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2006/z600987_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.