One-Pot Synthesis of Polyfunctionalized 4H-Chromenes and Dihydrocoumarins Based on Copper(II) Bromide-Catalyzed CC Coupling of Benzylic Alcohols with Ketene Dithioacetals
作者:Deqiang Liang、Mang Wang、Bahargul Bekturhun、Binbin Xiong、Qun Liu
DOI:10.1002/adsc.201000062
日期:——
The synthesis of polyfunctionalized 4H‐chromenes 3 and dihydrocoumarins 4 has been developed from the same substrates. Catalyzed by copper(II) bromide (0.3 equiv.), the reactions of the easily available ketene dithioacetals 1 with 2‐(hydroxymethyl)phenols 2 lead to 4H‐chromenes 3 in high to excellent yields in dichloromethane solvent, whereas, 3,4‐trans‐disubstituted dihydrocoumarins 4 are obtained
多官能团的4 H-色烯3和二氢香豆素4的合成是从相同的底物上开发的。通过铜催化(II)溴化物(0.3当量),将容易获得的乙烯酮二硫的反应1与2-(羟甲基)苯酚2引线至4 ħ -chromenes 3中高到在二氯甲烷溶剂优异的产率,反之,如图3所示,通过延长反应时间或将溶剂从二氯甲烷更改为乙腈,可以高收率和高非对映选择性获得4-反式-二取代二氢香豆素4。