A New Synthesis of 5-Arylbenzo[c]xanthones from Photoinduced Electrocyclisation and Oxidation of (E)-3-Styrylflavones
作者:Diana Pinto、Artur Silva、Djenisa Rocha、Tamás Patonay、José Cavaleiro
DOI:10.1055/s-0031-1290355
日期:2012.3
A new synthetic route to 5-arylbenzo[c]xanthones is established. This was accomplished by use the Heck reaction of 3-bromoflavones with styrene derivatives, leading to (E)-3-styrylflavones with total diastereoselectivity. This transformation was greatly improved under microwave irradiation. The one-pot, photoinduced electrocyclisation of (E)-3-styrylflavones and further in situ oxidation of the cycloadduct leads to 5-arylbenzo[c]xanthones.
建立了一条合成5-芳基苯并[c]咕吨酮的新路线。通过利用3-溴黄酮与苯乙烯衍生物的Heck反应,实现了立体选择性极高的(E)-3-苯乙烯基黄酮的合成。在微波照射下,这一转化得到了极大改善。通过(E)-3-苯乙烯基黄酮的一锅法光诱导电环化反应,并进一步原位氧化环加成产物,得到了5-芳基苯并[c]咕吨酮。