Rhodium-catalyzed chemo-, regio-, and enantioselective [2 + 2 + 2] cycloaddition of alkynes with isocyanates.
[reaction: see text] We have developed a cationic rhodium(I)/modified-BINAP complex-catalyzed chemoselective [2 + 2 + 2] cycloaddition of alkynes with isocyanates leading to a wide range of 2-pyridones. This method was successfully applied to the chemo-, regio-, and enantioselective synthesis of axially chiral 2-pyridones from unsymmetrical alpha,omega-diynes, bearing an ortho-substituted phenyl at one terminal position, and alkyl isocyanates.
Tanaka
Ken
K
Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan. tanaka-k@cc.tuat.ac.jp
Wada
Azusa
A
Noguchi
Keiichi
K