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
Transition-Metal-Free Approach to 4-Ethynylpyrimidines via Alkenynones
作者:Pavel R. Golubev、Alena S. Pankova、Mikhail A. Kuznetsov
DOI:10.1002/ejoc.201402045
日期:2014.6
A practical approach to the synthesis of 4-ethynylpyrimidines by the condensation of arylamidines with 2-aryl-1-ethoxy-5-(trimethylsilyl)pent-1-en-4-yn-3-ones has been developed. As these latter ketones are easily accessible from bis(trimethylsilyl)acetylene and arylacetyl chlorides, the regioselective condensation reported herein provides a facile access to both TMS-protected and unprotected 4-ethynylpyrimidines