The first chemoselective tandem acylation of the Blaise reaction intermediate: a novel method for the synthesis of α-acyl-β-enamino esters, key intermediate for pyrazoles
作者:Yu Sung Chun、Ki Kon Lee、Young Ok Ko、Hyunik Shin、Sang-gi Lee
DOI:10.1039/b813369g
日期:——
The Blaise reaction intermediate, a zinc bromide complex of β-enamino ester, could be activated in situ by addition of a stoichiometric or catalytic amount of n-BuLi to allow chemoselective tandem C2-acylation providing α-acyl-β-enamino esters, which are valuable intermediates for the syntheses of tri- and tetrasubstituted pyrazoles.
An effective and general method for the highly regioselective synthesis of 1-phenylpyrazoles from β-enaminoketoesters, tandem Blaise–acylation adducts
作者:Young Ok Ko、Yu Sung Chun、Cho-Long Park、Youngmee Kim、Hyunik Shin、Sungho Ahn、Jongki Hong、Sang-gi Lee
DOI:10.1039/b820324e
日期:——
effective and general route for the regioselective synthesis of 1-phenylpyrazoles has been developed from β-enaminoketoesters prepared by tandem Blaise–acylation. This method is applicable to a very broad range of substrates, generating a diverse set of 3-aryl-5-alkyl, 3-alkyl-5-aryl, 3,5-diaryl, and 3,5-dialkyl substituted pyrazoles regioselectively. The dichotomous regioselective synthesis of isotopically