Synthesis of [2-(Trimethylsilyl)ethynyl]pyrazoles Based on Bis(trimethylsilyl)acetylene and Arylacetyl Chlorides
作者:Alena S. Pankova、Pavel R. Golubev、Ivan V. Ananyev、Mikhail A. Kuznetsov
DOI:10.1002/ejoc.201200807
日期:2012.10
A practical approach to the synthesis of [2-(trimethylsilyl)ethynyl]pyrazoles was developed through condensation of hydrazines with enynones that are easily accessible frombis(trimethylsilyl)acetylene and arylacetyl chlorides. Optimized conditions for reactions with monoarylhydrazines permit the chemoselective formation of 5-alkynylpyrazoles in high yields (48–94 %). When monoalkylhydrazines or the