Superior effect of a pi-acceptor ligand (phosphine-electron-deficient olefin ligand) in the Negishi coupling involving alkylzinc reagents.
Palladium-catalyzed Negishi cross-coupling involving primary and secondary alkyls, even in the presence of beta-H, can be achieved at ambient temperature using chelating ligands containing a phosphine and an electron-deficient olefin. The superior effects of the ligands were shown not only in the desired cross-coupling product yields but also in the fast reaction at mild conditions. This reaction has been also scaled up to 50 g in 0.005 mol % catalyst (20,000 TONs) at room temperature.
Luo
Xiancai
X
College of Chemistry and Molecular Sciences, Wuhan University, PR China.
Zhang
Heng
H
Duan
Hui
H
Liu
Qiang
Q
Zhu
Lizheng
L
Zhang
Tony
T
Lei
Aiwen
A