Beilstein J. Org. Chem.2011,7, 897–936, doi:10.3762/bjoc.7.103
Imines and oximes are versatile synthetic intermediates for the preparation of dyes, pharmaceuticals, and agricultural chemicals. Sun et al. have reported a multi-task Au/hydroxyapatite reagent for the heterogeneous catalyzed oxidation of alcohols and amines to imines or oximes [56]. N-alkylation of
. In addition to intermolecular addition, Mukherjee and Widenhoefer recently reported a gold(I)-catalyzed intramolecular amination of allylic alcohols 130 with alkylamines (Scheme 23) [61].
3.2 Imines as nucleophiles
Gold-catalyzed cyclizations of O-propioloyl oximes via C–N bond formation followed by
Beilstein J. Org. Chem.2007,3, No. 20, doi:10.1186/1860-5397-3-20
-3-methanesulfonates and 4-oximino-2,3-dihydrobenzoxathiin-2,2-dioxides (sultone oximes) is described. These compounds are important intermediates for the preparation of zonisamide, an anti-convulsant drug.
Background
3-Alkyl-1,2-benzisoxazole derivatives are known to have important biological
was developed by Dianippon of Japan.
Compounds 1 were originally prepared from the rearrangement of coumarin-4-one oximes 3 as shown in Scheme 1.
The 1,2-benzisoxazole-3-acetic acids were converted into halogenated compounds, then reacted with various different nucleophiles to generate the compounds 1
) failed to produce the cyclised products and gave only salicylic acid derivatives. All the 1,2-benzoxathiin-4(3H)-one-2,2-dioxides 6 were characterised from their analytical and spectral data.
Conversion of ketones 6 into the corresponding oximes 5 proceeded uneventfully, and oximes 5 were characterised
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Graphical Abstract
Scheme 1:
Conversion of coumarin-4-one oximes to 3-alkyl-1,2-benzisoxazole derivatives.