ol7b01447_si_001.pdf (2.64 MB)
A Regioselective Approach to Trisubstituted Pyrazoles via Palladium-Catalyzed Oxidative Sonogashira-Carbonylation of Arylhydrazines
journal contribution
posted on 2017-06-22, 17:20 authored by Yongliang Tu, Zhenming Zhang, Tao Wang, Jiamei Ke, Junfeng ZhaoA palladium-catalyzed
oxidative carbonylation of arylhydrazines
and alkynes with balloon pressure CO/O2 to afford trisubstituted
pyrazoles in a one-pot manner has been developed. The formation of
trisubstituted pyrazoles involves a sequential C–N bond cleavage,
carbonylation, Sonogashira coupling, Michael addition, and intramolecular
condensation cyclization tandem process. An unprecedented oxidative
Sonogashira-carbonylation reaction of arylhydrazine plays a key role
for such a facile approach to pyrazoles.
