A copper- and amine-free sonogashira reaction employing aminophosphines as ligands.
An efficient Pd-catalyzed Sonogashira coupling reaction was achieved in the absence of a copper salt or amine with an inorganic base and easily prepared, air-stable aminophosphine ligands in commonly used organic solvents; good to excellent yields were obtained. Under optimized reaction conditions, the Sonogashira coupling reaction occurred selectively when an enyne substrate was employed and no Heck reaction product was detected; acetone-masked acetylene and trimethylsilylacetylene can also be efficiently coupled, providing a method to make terminal alkynes.
Cheng
Jiang
J
Department of Chemistry, Nanjing University, 22 Hankou Road, Nanjing 210093, China.
Sun
Yanhui
Y
Wang
Feng
F
Guo
Minjie
M
Xu
Jian-Hua
JH
Pan
Yi
Y
Zhang
Zhaoguo
Z