The palladium-catalysed four-component coupling of a halide, terminal alkyne, molybdenum hexacarbonyl and either a hydrazine or amidine has been shown to be an efficient method for the construction of highly substituted pyrazoles and pyrimidines, respectively, in a one-pot process.
A Novel One-Pot Method for the Preparation of Pyrazoles by 1,3-Dipolar Cycloadditions of Diazo Compounds Generated in Situ
作者:Varinder K. Aggarwal、Javier de Vicente、Roger V. Bonnert
DOI:10.1021/jo0268409
日期:2003.6.1
procedure for the preparation of pyrazoles by 1,3-dipolar cycloaddition of diazocompounds generated in situ has been developed. Diazocompounds derived from aldehydes were reacted with terminal alkynes to furnish regioselectively 3,5-disubstituted pyrazoles. Furthermore, the reaction of N-vinylimidazole and diazocompounds derived from aldehydes gave exclusively 3-substituted pyrazoles in a one-pot process
Copper on iron promoted one-pot synthesis of β-aminoenones and 3,5-disubstituted pyrazoles
作者:Szabolcs Kovács、Zoltán Novák
DOI:10.1016/j.tet.2013.08.047
日期:2013.10
The reaction of hydroximoyl chlorides with acetylenes in the presence of a copper on iron bimetallic system leads to beta-aminoenones via reductive ring opening of isoxazole intermediates. The valuable beta-aminoenone building blocks can be isolated or transformed into pyrazoles with the addition of hydrazine in a straightforward one-pot procedure. (C) 2013 Elsevier Ltd. All rights reserved.