affords the corresponding pyran annulated heterocyclic systems in high yields at room temperature in 3 h. The work-up procedure is very simple, and the products do not require further purification. The catalysts can be recycled and reused several times without observable loss of performance. Graphical abstract
摘要 描述了各种活化的CH-酸和
四氰基乙烯之间的TiO 2催化反应。该反应在室温下3小时内以高收率提供了相应的
吡喃环化的杂环系统。后处理程序非常简单,产品不需要进一步纯化。催化剂可以循环使用多次,而不会出现性能损失。 图形概要