Observation of Diastereomeric Interconversions of β‐Sulfinylsubporphyrins as Evidence for Bowl Inversion. Issue 33 (11th June 2015)

• Record Type: Journal Article
• Authors: Yoshida, Kota; Osuka, Atsuhiro
• Is Part Of: Chemistry. Volume 21:Issue 33(2015)
• Page Start: 11727
• Page End: 11734
• Publication Date: 2015-06-11
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201501546
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p> <italic>B</italic>‐Methoxy β‐(4‐methoxyphenylsulfinyl)subporphyrin and <italic>B</italic>‐phenyl β‐(4‐methoxyphenylsulfinyl)subporphyrin were synthesized by oxidation of the corresponding β‐sulfanylsubporphyrins with <italic>m</italic>‐chloroperbenzoic acid and were separated into diastereomers, respectively. <italic>B</italic>‐Methoxy subporphyrin diastereomers were interconverted to each other in methanol or ethanol, whereas such interconversion was not observed for <italic>B</italic>‐phenyl subporphyrin diastereomers even at high temperature. Diastereomeric interconversions of <italic>B</italic>‐methoxy subporphyrins were dramatically accelerated by addition of trifluoroacetic acid. These results suggest that the diastereomeric interconversions of <italic>B</italic>‐methoxy subporphyrins, namely, their bowl inversions, proceed via a mechanism involving protonation‐induced generation of subporphyrin borenium cations followed by nucleophilic attacks by alcohols.</p> </abstract>