Palladium-catalyzed preparation of vinylallenes from 2-bromo-1,3,5-trienes via an alkylidene-pi-allylpalladium-mediated formal SN2" pathway.
[Structure: see text] A novel Pd-catalyzed reaction to prepare conjugated vinylallenes from 2-bromo-1,3,5-triene and a soft nucleophile via a formal SN2" pathway was developed. The reaction proceeds via alkylidene-pi-allylpalladium and allenyl-pi-allylpalladium intermediates, and a dynamic process involving the two palladium intermediates played important roles in determining the selectivity of the Pd-catalyzed reaction. The reaction was extended to an asymmetric counterpart, and an axially chiral vinylallene was obtained with up to 81% ee.
Ogasawara
Masamichi
M
Catalysis Research Center and Graduate School of Pharmaceutical Sciences, Hokkaido University and SORST, Japan Science and Technology Agency (JST), Kita-ku, Sapporo 001-0021, Japan. ogasawar@cat.hokudai.ac.jp
Fan
Liyan
L
Ge
Yonghui
Y
Takahashi
Tamotsu
T
D000466:Alkadienes / Q000737:chemistry*; D002384:Catalysis; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry*
D000466:Alkadienes; D010165:Palladium