Versatile and Expeditious Synthesis of Aurones via Au<sup>I</sup>-Catalyzed Cyclization
作者:Hassina Harkat、Aurélien Blanc、Jean-Marc Weibel、Patrick Pale
DOI:10.1021/jo702197b
日期:2008.2.1
Aurones are conveniently formed in a three-step procedure including a goldI-catalyzed cyclization of 2-(1-hydroxyprop-2-ynyl)phenols as a highly regio- and stereoselective key step. A wide diversity of derivatives can be obtained starting from substituted salicylaldehydes. Synthesis of natural 4,6,3‘,4‘-tetramethoxyaurone and structure revision of two natural products (dalmaisione D and 4‘-chloroaurone)
Water-Promoted, Silver–Phosphine Complex–Catalyzed Stereoselective Cyclization of 2-(1-Hydroxy-3-arylprop-2-ynyl)phenols Leading to a Highly Efficient Approach to Aurones
作者:Mingdeng Lin、Min Yu、Chengyan Han、Chao-Jun Li、Xiaoquan Yao
DOI:10.1080/00397911.2010.517613
日期:2011.11.1
Silver-phosphine complexes can be utilized as highly efficient catalysts for the cyclization of 2-(1-hydroxy-3-arylprop-2-ynyl)phenols (1) to give product 2, key intermediates to synthesize aurones (4), with good yields and stereoselectivities in water-toluene mixed solvent. With fluoride as the counteranion, complete E- or Z-stereoselectivities were achieved at high temperature or room temperature, respectively. Furthermore, after removing water from the reaction mixtures, the toluene solution containing crude products 2 can be treated by MnO2 directly without further purification, to give aurones 4 in good yields.