Crystalline Cyclic (Alkyl)(amino)carbene‐tetrafluoropyridyl Radical. Issue 23 (29th April 2015)

• Record Type: Journal Article
• Authors: Styra, Steffen; Melaimi, Mohand; Moore, Curtis E.; Rheingold, Arnold. L.; Augenstein, Timo; Breher, Frank; Bertrand, Guy
• Is Part Of: Chemistry. Volume 21:Issue 23(2015)
• Page Start: 8441
• Page End: 8446
• Publication Date: 2015-04-29
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201500740
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>A stable cyclic (alkyl)(amino)carbene (CAAC) <bold>1</bold> inserts into the <italic>para</italic>‐CF bond of pentafluoropyridine, and after fluoride abstraction, the iminium‐pyridyl adduct [<bold>3</bold>]⁺ was isolated. A cyclic voltammetry study shows a reversible three‐state redox system involving [<bold>3</bold>]⁺, [<bold>3</bold>]^{<bold>⋅</bold>}, and [<bold>3</bold>]^{<bold>−</bold>}. The CAAC‐pyridyl radical [<bold>3</bold>]^{<bold>⋅</bold>}, obtained by reduction of [<bold>3</bold>]⁺ with magnesium, has been spectroscopically and crystallographically characterized. In contrast to the lack of π communication between the CAAC and the pyridine units in cation [<bold>3</bold>]⁺, the unpaired electron of [<bold>3</bold>]^{<bold>⋅</bold>} is delocalized over an extended π system involving both heterocycles.</p> </abstract>