Convenient one-pot syntheses of pyrazoles from imines, a vilsmeier type reagent and hydrazine
A simple one-pot procedure for the regioselective synthesis of pyrazoles from readily available starting materials is described. Vilsmeier type reagent 1 reacts with imines 10 (via the corresponding tautomeric secondary enamines) in tetrahydrofuran to give enaminoimine hydrochlorides 11. Nonsymmetrical imines generally react preferentially with 1 at the sterically less hindered α-position. The enaminoimine hydrochlorides 11 are transformed in situ to the corresponding pyrazoles 12 in moderate to high yields by the addition of hydrazine.
Zinc(II)-Catalyzed Synthesis of Propargylamines by Coupling Aldimines and Ketimines with Alkynes
A ZnII-catalyzed reaction between imines, which were derived from unactivated aldehydes or ketones and primary amines or α-amino acid esters, and terminal alkynes has led to the rapid and efficient formation of tri- and tetrasubstituted propargylamines (from aldimines and ketimines, respectively) in good to excellent yields. No additives or extra Lewis acid reagents were required for the imine-alkyne coupling reaction.
Shehzadi, Syeda Aaliya,Saeed, Aamer,Lemière, Filip,Maes, Bert U. W.,Abbaspour Tehrani, Kourosch
supporting information
p. 78 - 88
(2018/03/27)
Conformational and structural analysis of exocyclic olefins and ketimines by multinuclear magnetic resonance
The 1H, 13C, and 15N NMR spectra of 5 exocyclic alkenes and 15 different ketimines obtained from cyclohexanone and derivatives using benzyl bromide and primary amines - are analyzed. Relative stereochemical and preferentia
Montalvo-Gonzalez, Ruben,Montalvo-Gonzalez, J. Ascencion,Ariza-Castolo, Armando
experimental part
p. 907 - 912
(2009/05/09)
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