Tert‐Butyl Hydroperoxide and Tetrabutylammonium Iodide‐ Promoted Free Radical Cyclization of α‐Azido‐N‐arylamides. Issue 14 (21st September 2014)

• Record Type: Journal Article
• Authors: Li, Dianjun; Yang, Tonghao; Su, Hailin; Yu, Wei
• Is Part Of: Advanced synthesis & catalysis. Volume 356:Issue 14/15(2014)
• Page Start: 3148
• Page End: 3156
• Publication Date: 2014-09-21
• Subjects: Catalysis -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Chemistry -- Periodicals; Chemistry, Technical -- Periodicals; Chemistry -- Periodicals; Catalysis -- Periodicals; Technology, Pharmaceutical -- Periodicals; 547.2
• DOI: 10.1002/adsc.201400420
• Languages: English
• ISSNs: 1615-4150

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The oxidizing system of <italic>tert</italic>‐butyl hydroperoxide (TBHP) and tetrabutylammonium iodide (TBAI) is capable of engendering α‐(aminocarbonyl)iminyl radicals from α‐azido‐<italic>N</italic>‐phenylacetamides. These iminyl radicals preferably undergo intramolecular attack on the benzene ring to give azaspirocyclohexadienyl radicals, which are readily captured by O₂ under an oxygen atmosphere to yield azaspirocyclohexadienones. In the absence of oxygen, the reaction will afford quinoxalin‐2‐one products. The generation of α‐(aminocarbonyl)iminyl radicals is proposed to involve an initial deprotonation and denitrogenation, and subsequent oxidation of thus formed imine intermediates by <italic>tert</italic>‐butoxy radical and/or <italic>tert</italic>‐butyl peroxyl radical.</p> <p> <boxed-text content-type="graphic" position="anchor" orientation="portrait"> <graphic position="anchor" mimetype="image" xlink:href="ark:/27927/pgh1fbrp3qc" orientation="portrait" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /> </boxed-text> </p> </abstract>