A new ruthenium-catalyzed hydrogen-transfer reaction: transformation of 3-benzyl but-1-ynyl ethers into 1,3-dienes and benzaldehyde.
We report a ruthenium-catalyzed reaction for various 3-benzyl but-1-ynyl ethers with suitable functionalities. Treatment of these substrates with TpRu(PPh3)(CH3CN)2PF6 (8.0 mol %) catalyst in 1,2-dichloroethane (80 degrees C, 12 h) afforded functionalized 1,3-dienes and benzyl aldehyde in good yields. This process is considered to be a tandem dealkoxylation and transfer hydrogenation. Deuterium-labeling experiments reveal that the migration of different hydrogen atoms proceeds regiospecifically. A plausible mechanism is proposed on the basis of the results of isotope experiment.
Yeh
Kuo-Liang
KL
Department of Chemistry, National Tsing-Hua University, Hsinchu, Taiwan, ROC.
Liu
Bo
B
Lo
Ching-Yu
CY
Huang
Heh-Lung
HL
Liu
Rai-Shung
RS