Sequential Synthesis of Furans from Alkynes: Successive Ruthenium(II)- and Copper(II)-Catalyzed Processes
作者:Min Zhang、Huan-Feng Jiang、Helfried Neumann、Matthias Beller、Pierre H. Dixneuf
DOI:10.1002/anie.200805531
日期:——
5‐Disubstituted furans can be prepared from terminal alkynes in one pot using two successive catalytic reactions (see scheme; p‐TSA=para‐toluenesulfonic acid). First, a 1,3‐dienyl alkyl ether is produced by the dimerization of a terminal alkyne and addition of an alcohol catalyzed by [RuCp*(NCMe)3][PF6]. Then, consecutive hydrolysis and cyclization catalyzed by CuCl2 provides the 2,5‐disubstituted furan.
逐步实施:可以在一个锅中使用两个连续的催化反应,从末端炔烃中制备2,5-二取代的呋喃(参见方案;p- TSA =对甲苯磺酸)。首先,通过末端炔的二聚反应和通过[RuCp *(NCMe)3 ] [PF 6 ]催化的醇的加成反应生成1,3-二烯基烷基醚。然后,由CuCl 2催化的连续水解和环化反应可提供2,5-二取代的呋喃。