Rhodium-Catalyzed Chemo-, Regio-, and Enantioselective [2 + 2 + 2] Cycloaddition of Alkynes with Isocyanates
作者:Ken Tanaka、Azusa Wada、Keiichi Noguchi
DOI:10.1021/ol052041b
日期:2005.10.1
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.
Efficient syntheses of α-pyridones and 3(2H)-isoquinolones through ruthenium-catalyzed cycloisomerization of 3-en-5-ynyl and o-alkynylphenyl nitrones
作者:Kamalkishore Pati、Rai-Shung Liu
DOI:10.1039/b910773h
日期:——
We report a new catalytic synthesis of α-pyridones and 3(2H)-isoquinolones from readily available 3-en-5-ynyl nitrones and o-alkynylphenyl nitrones; the reaction mechanism is proposed to involve iminyl ketene species through an oxygen transfer process.