Solvent influence in the Rh-catalyzed intramolecular 1,6 C–H insertions: a general approach to the chromane and flavanone skeletons
摘要:
Solvent polarity and nature of the ligands on the catalyst are crucial factors that control the regioselectivity of the Rh(II) promoted intramolecular 1,6 C-H insertions versus the 3-elimination. We have explored the best conditions for the preparation of flavanones and chromenes through this approach. The procedure is also an excellent way of preparing stereochemically pure Z aryl-alkenes. (C) 2011 Elsevier Ltd. All rights reserved.
Solvent influence in the Rh-catalyzed intramolecular 1,6 C–H insertions: a general approach to the chromane and flavanone skeletons
摘要:
Solvent polarity and nature of the ligands on the catalyst are crucial factors that control the regioselectivity of the Rh(II) promoted intramolecular 1,6 C-H insertions versus the 3-elimination. We have explored the best conditions for the preparation of flavanones and chromenes through this approach. The procedure is also an excellent way of preparing stereochemically pure Z aryl-alkenes. (C) 2011 Elsevier Ltd. All rights reserved.
Conjugate addition of cuprate reagents to chromones: A route to 2-substituted chroman-4-ones
作者:Suthiweth T. Saengchantara、Timothy W. Wallace
DOI:10.1016/s0040-4020(01)88394-0
日期:1990.1
Chromones (4-oxo-4H-1-benzopyrans) activated by electron-withdrawing groups attached to C-3 undergo efficient 1,4-additon of cuprate reagents, producing 2,3-disubstituted chroman-4-ones. The addition products from methyl chromone-3-carboxylates can be converted into 2-substitutedchroman-4-ones by treatment with sodium chloride in wet dimethylsulphoxide.