Regioselective Synthesis of 1-Aryl-3,4-substituted/annulated-5-(methylthio)pyrazoles and 1-Aryl-3-(methylthio)-4,5-substituted/annulated Pyrazoles
摘要:
Highly efficient and regioselective synthesis of 1-aryl-3,4-substituted/annulated-5-(methylthio)-pyrazoles and 1-aryl-3-(methylthio)-4,5-substituted/annulated pyrazoles has been reported via cyclocondensation of arylhydrazines with either alpha-oxoketene dithioacetals or beta-oxodithioesters.
species of selenium were easily generated in situ by the reaction of diorganyl diselenides with Oxone® in ethanol as solvent in an open-flask at 70 °C. These electrophilic selenium species were employed in the selenylation/cyclization of α,β-alkynyl hydrazones, giving the title compounds in moderate to excellent yields. The final species of selenium obtained from the reaction of diphenyl diselenide with
PTSA-catalyzed Mannich-type–cyclization–oxidation tandem reactions: one-pot synthesis of 1,3,5-substituted pyrazoles from aldehydes, hydrazines and alkynes
作者:Pei Liu、Ying-Ming Pan、Yan-Li Xu、Heng-Shan Wang
DOI:10.1039/c2ob25487e
日期:——
A convenient one-pot Mannich-type–cyclization–oxidation tandem process has been developed for the synthesis of 1,3,5-trisubstituted pyrazoles derivatives fromaldehydes, hydrazines and alkynes using p-toluenesulfonic acid monohydrate (PTSA) as a multifunctional catalyst. This method provides a flexible and rapid route to 1,3,5-trisubstituted pyrazoles.
C<sub>sp<sup>3</sup></sub>–C<sub>sp<sup>3</sup></sub> Bond Cleavage in the Palladium-Catalyzed Aminohydroxylation of Allylic Hydrazones Using Atmospheric Oxygen as the Sole Oxidant
作者:Yu-Chen Chen、Ming-Kui Zhu、Teck-Peng Loh
DOI:10.1021/acs.orglett.5b01127
日期:2015.6.5
A C–C bond cleavage was observed in the palladium-catalyzed aminohydroxylation of allylic hydrazones, using atmospheric oxygen as the soleoxidant. This reaction could also proceed in a one-pot manner, starting from keto-alkene compounds and phenylhydrazine.