Hydrogen bonding-promoted efficient Ru-catalyzed ring-closing metathesis of demanding homoallyl 2-(hydroxymethyl)acrylates.
An efficient hydrogen bonding-guided ring-closing metathesis (RCM) reaction of sterically demanding homoallyl 2-(hydroxymethyl)acrylates catalyzed by the Hoveyda-Grubbs 2nd generation catalyst was developed and the reaction mechanism was explored. Adding a substituent to the hydroxymethyl group in this scaffold resulted in a class of challenging RCM substrates, although usable yields could be obtained. However, substrates bearing a 1-oxygenated alkyl group on the homoallylic carbon gave excellent RCM yields, providing a practical solution. Experimental and computational evidence indicated an unusual directing effect of OHCl hydrogen bonding between the substrate and Ru catalyst, which guides Ru to interact with the electron-deficient, more hindered acrylic C[double bond, length as m-dash]C bond and thus triggers the RCM process.
Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China. yuehaishen@gmail.com.
Liang
L
Feng
Yuehui
Y
Liu
Bo
B
Hou
Zaifeng
Z
Yuan
Fu-Chao
FC
Yu
Tingbin
T
Yan
Qi
Q
Qin
Ruigeng
R
Ji
Ya-Min
YM
Li
Yuehai
Y
Shen
Zhi-Li
ZL
Zuo