Transition metal catalyzed oxidations, 3. Reaction of 4-hydroxy[2.2]paracyclophane with the mimoun molybdenum oxodiperoxo complex [Mo(O2)2O]· Py · HMPT

✍ Scribed by Krohn, Karsten ;Rieger, Hagen ;Hopf, Henning ;Barrett, David

• Publisher: Wiley (John Wiley & Sons)
• Year: 1990
• Tongue: English
• Weight: 440 KB
• Volume: 123
• Category: Article
• ISSN: 0009-2940
• DOI: 10.1002/cber.19901230824

✦ Synopsis

Treatment of I-hydroxy[2.2]paracyclophane (1) with the Mim-(4). This dienone dimerizes at room temperature to afford the oun molybdenum oxodiperoxo complex [Mo(O&O] . Py . Diels-Alder adduct 5, whose structure was confirmed by X-ray HMPT gives 3,4-dihydro-3-hydroxy-4-oxo[2.2]paracyclophane analysis.

Recently, we have described the specific oxidation of phenols to ortho-quinones using tert-butyl hydroperoxide and transition metal complexes or the Mimoun molybdenum oxodiperoxo complex [Mo(O2),0]. Py . HMPT']. This reaction is initiated by replacement of one ligand of the complex by the phenol, as depicted in I, followed by oxygenation and dehydrogenation processes ' I. The exact mechanism of the oxygen transfer is as yet unknown. In this paper the reaction of 4-hydroxy[2.2]paracyclophane (1) with [MO(O')~-01. Pya HMPT is described; it provides insight into the nature of the oxygen-transfer step and yields a structurally new type of paracyclophane dimer.

Miyahara et aL4) have described the isolation of a 1 : 1 mixture of the ortho-, 2, and the para-quinone 3 obtained by the reaction of 1 with diphenylselenic anhydride (Barton's reagent