Cu(II)-Cu(I) synergistic cooperation to lead the alkyne C-H activation.
An efficient alkyne C-H activation and homocoupling procedure has been studied which indicates that a Cu(II)/Cu(I) synergistic cooperation might be involved. In situ Raman spectroscopy was employed to study kinetic behavior, drawing the conclusion that Cu(I) rather than Cu(II) participates in the rate-determining step. IR, EPR, and X-ray absorption spectroscopy evidence were provided for structural information, indicating that Cu(I) has a stronger interaction with alkyne than Cu(II) in the C-H activation step. Kinetics study showed Cu(II) plays a role as oxidant in C-C bond construction step, which was a fast step in the reaction. X-band EPR spectroscopy showed that the coordination environment of CuCl2(TMEDA) was affected by Cu(I). A putative mechanism with Cu(I)-Cu(II) synergistic cooperation procedure is proposed for the reaction.
College of Chemistry and Molecular Sciences, Wuhan University , Wuhan 430072, P.R. China.
Ruopeng
R
Bai
Guanghui
G
Zhang
Hong
H
Yi
Zhiliang
Z
Huang
Xiaotian
X
Qi
Chao
C
Liu
Jeffrey T
JT
Miller
A Jeremy
AJ
Kropf
Emilio E
EE
Bunel
Yu
Y
Lan
Aiwen
A
Lei
D000480:Alkynes / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D007700:Kinetics; D009942:Organometallic Compounds / Q000737:chemistry*
D000480:Alkynes; D009942:Organometallic Compounds; D003300:Copper