A New H2O2/Acid Anhydride System for the Iodoarene-Catalyzed C−C Bond-Forming Reactions of Phenols
摘要:
We have succeeded in the first versatile iodoarene-catalyzed C-C bond-forming reactions by development of a new reoxidation system at low temperatures using stoichiometric bis(trifluoroacetyl) peroxide A in 2,2,2-trifluoroethanol (TFE). The catalytic system supplies a wide range of substrates and functional availabilities sufficient to be used in the key synthetic process of producing biologically important Amaryllidaceae alkaloids.
Efficient phenolic oxidations using μ-oxo-bridged phenyliodine trifluoroacetate
作者:Toshifumi Dohi、Teruyoshi Uchiyama、Daisuke Yamashita、Naohiko Washimi、Yasuyuki Kita
DOI:10.1016/j.tetlet.2010.12.037
日期:2011.4
The excellent oxidizing behavior of the mu-oxo-bridged phenyliodine trifluoroacetate 1 is revealed during the phenolic oxidations mediated by hypervalent iodine(III) reagents. The use of the mu-oxo-bridged compound 1 instead of PhI(OAc)(2) (PIDA) and PhI(OCOCF3)(2) (PIFA) during the oxidative cyclization of phenols involving carbon-oxygen, carbon-nitrogen, and carbon-carbon bond formations could produce spirocyclized cyclohexadienones in comparable or somewhat better yields. Thus, we have concluded that the unique reagent 1 is a promising alternative to PIDA and PIFA, and the use of reagent 1 as a reasonable choice is recommended for the hypervalent iodine(III)-mediated phenolic oxidations as well as other transformations. (C) 2010 Elsevier Ltd. All rights reserved.