A Fischer-Type Ruthenium Carbene Complex as a Metathesis Catalyst for the Synthesis of Enol Ethers
作者:Xia-Lin Wang、Nicholas Yiching Chiang、Jian-Jhih Peng、Lei Yu、Li-Jun Xu、Hau-Ren Yang、Bih-Yaw Jin、Pinglu Zhang、Yu-Ying Lai、Ze Li、Guo-Qiao Lai、Tien-Yau Luh
DOI:10.1021/acs.joc.1c01741
日期:2021.12.17
strain and nucleophilicity of the double bond. Anchimeric participation of an electron-rich group would result in significant enhancement of the reactivity, and the t50 could be as short as several minutes. A similar substrate without such a neighboring group shows a much slower rate. An exo-norborne derivative reacts much faster than the corresponding endo-isomer. Alkenes with poor nucleophilicity are less
Grubbs GI 或 G-II 催化剂产生钌乙氧基卡宾配合物,该配合物催化张力环烯烃的开环交叉复分解 (ROCM) 以产生二烯,其中产物中的两个烯烃部分之一含有乙氧基取代基。没有检测到聚合物产品。母体降冰片烯或取代环丙烯等烃类可以顺利进行反应。叔胺、N-烷基酰亚胺、酯和芳基或烷基溴在反应条件下保持完整。除了乙烯基醚之外,还可以使用乙烯基酯。达到 ROCM 产品 50% 收率所需的时间t 50取决于双键的应变和亲核性,从 0.01 到 140 小时不等。富电子基团的嵌合参与将导致反应性的显着增强,并且t 50可以短至几分钟。没有这种相邻基团的类似底物显示出慢得多的速率。一个外切-norborne衍生物发生反应要比相应的更快内-异构体。亲核性差的烯烃不太受 ROCM 工艺的青睐,因此应变较小的环辛烯也是如此。