In this work, an efficient palladiumcatalyzed annulation of 2-iodobiphenyl with a non-terminal alkene was developed. The key factor in this transformation was the formation of a highly reactive oxo-palladacycle intermediate, which was enabled by a neighboring hydroxyl group, and remarkably restrained the β-H elimination process. Mechanistically, control experiments demonstrated that the hydroxyl group
The design and development of a truly nano heterogeneous catalyst for the Claisen-Schmidt condensation (CSC) of benz-aldehydes with 2-hydroxyacetophenone to yield substituted chalcones followed by isomerization to afford flavanones with excellent yields and selectivity is described. (C) 2005 Elsevier Ltd. All rights reserved.
30. Synthesis of 7-halogenoflavone and related compounds
作者:F. C. Chen、C. T. Chang
DOI:10.1039/jr9580000146
日期:——
Pd-Catalyzed Hydroxyl-Directed Cascade Hydroarylation/C–H Germylation of Nonterminal Alkenes and Aryl Iodides
Ionic liquid mediated Cu-catalyzed cascade oxa-Michael-oxidation: efficient synthesis of flavones under mild reaction conditions
作者:Zhiyun Du、Huifen Ng、Kun Zhang、Huaqiang Zeng、Jian Wang
DOI:10.1039/c1ob06209c
日期:——
Flavonoids are a class of natural products, found in a wide range of vascular plants and dietary components. Their low toxicity and extensive biological activities, including anti-cancer and anti-bacterial, have made them attractive candidates to serve as therapeutic agents for many diseases. Herein, we disclose a highly efficient synthetic method of CuI-catalyzed cascade oxa-Michael-oxidation, using chalcones as substrates, mediated by the ionic liquid [bmim][NTf2] at a low temperature. This efficient synthetic method has demonstrated high synthetic utility and can afford flavones in good to high yields (up to 98%).