A facile 2<i>H</i>-chromene dimerization through an <i>ortho</i>-quinone methide intermediate catalyzed by a sulfonyl derived MIL-101 MOF
作者:Xin Du、Xiujuan Li、Houliang Tang、Wenyu Wang、Daniele Ramella、Yi Luan
DOI:10.1039/c8nj01354c
日期:——
SEM, XRD, FTIR, BET and TGA. An efficient and diastereoselective homo-dimerization of 2H-chromenes catalysis was achieved using the sulfonyl derived MIL-101 MOF as a catalyst. A benzopyranobenzopyran polycyclic structure was generated in high yield and diastereoselectivity under mild catalytic reaction conditions. Furthermore, a regio-isomer was observed when 2H-chromene bears different substitution
MIL-101–SO 3 H MOF是使用市售材料合成的。合成后的MIL-101-SO 3 H的特征在于SEM,XRD,FTIR,BET和TGA。使用磺酰基衍生的MIL-101 MOF作为催化剂,可实现2 H-苯甲基二烯催化的高效非对映选择性均二聚。在温和的催化反应条件下,以高收率和非对映选择性生成了苯并吡喃并苯并吡喃多环结构。此外,当2 H-色烯带有不同的取代基时,观察到一个区域异构体,从而提供了chromeno [2,3- b] chromene二聚体,收率高,非对映选择性好。提出了一种具有串联重排/杂-Diels-Alder反应序列的机制,这得到了证据的支持。此外,酸性MIL-101 MOF催化剂可以循环使用十次,而不会影响收率和选择性。