Synthesis of Functionalized Pseudopeptides through Five-Component Sequential Ugi/Nucleophilic Reaction of <i>N</i>-Substituted 2-Alkynamides with Hydrazides
Five-component sequential Ugi/nucleophilic addition reaction of aromatic aldehydes, primary amines, propiolic acid, isocyanides, and hydrazides has been developed in order to access polyfunctional pseudopeptides. The reaction may proceed through formation of N-substituted 2-alkynamides as intermediates. This process is found to be mild and operationally simple with broad substrate scope.
Reactions of Arylpropynehydrazides with Substituted Malonyl Chlorides: A Route to Pyrazolo-Condensed 1,3-Oxazines
作者:Olga A. Petina、Igor P. Yakovlev、Detlef Geffken
DOI:10.1002/ejoc.201200267
日期:2012.6
Reaction of phenylpropynehydrazide with dimethylmalonyl chloride furnished the corresponding 4,4-dimethyl-1-(3-phenylprop-2-ynoyl)pyrazolidine-3,5-dione, which upon thermolysis underwent a 6-endo-dig cyclization to a pyrazolo[5,1-b][1,3]oxazine. The corresponding reaction of arylpropynehydrazides with monosubstituted malonyl chlorides furnished pyrazolo[5,1-b][1,3]oxazine-7-ones via intermediates that