Intramolecular hydroamination of alkynes catalyzed by Pd(PPh3)4/triphenylphosphine under neutral conditions.
The intramolecular hydroamination of alkynes tethered with amino group 1 in the presence of catalytic amounts of Pd(PPh3)4 and PPh3 in benzene at 100 degrees C proceeded smoothly without the use of any additional acid source to afford five- and six-membered nitrogen heterocycles 2 in good to excellent yields. A compulsory addition of carboxylic acid as a cocatalyst was not needed, and the reaction could be carried out under essentially neutral conditions.
Bajracharya
Gan B
GB
Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
Huo
Zhibao
Z
Yamamoto
Yoshinori
Y