N-Allylation versus C-allylation of intermediates from aza-Michael adducts of arylideneisoxazol-5-ones
Journal
Organic and Biomolecular Chemistry
Journal Volume
18
Journal Issue
46
Pages
9516-9525
Date Issued
2020
Author(s)
Abstract
Reactions of arylidene-isoxazol-5-ones with intermediates from palladium-catalysed decarboxylation of allyl carbamates proceeded through aza-Michael addition and N-allylation to give the corresponding bis-adducts, β-amido-N-allylated products, in good yields. In similar reactions with 4-vinyl-1,4-dihydro-2H-3,1-benzoxazin-2-one, a cyclic allyl carbamate, C-allylation took place to yield a series of spiro[isoxazole-4,3-quinolin]-5-ones in high yields. Regio-selective N-versus C-allylation is illustrated to occur in an inter-versus intra-molecular fashion. The structure and stereochemistry of these products are determined by NMR spectroscopy and further confirmed by X-ray crystallography. This work offers an excellent method for the preparation of various substituted isoxazol-5-ones. This journal is ? The Royal Society of Chemistry.
Subjects
Addition reactions; Carboxylation; Nuclear magnetic resonance spectroscopy; Reaction intermediates; X ray crystallography; Aza-Michael addition; Bis-adducts; High yield; Isoxazoles; Michael adducts; Regio-selective; Allylation; allylation; article; nuclear magnetic resonance spectroscopy; stereochemistry; X ray crystallography
Type
journal article