Selective Propargylation of Azo Compounds with Barium Reagents

Abstract

A Barbier-type propargylation of azo compounds with γ-trialkylsilylated propargylic bromides has been achieved using reactive barium as a low-valent metal in THF. Corresponding propargylated hydrazines (α-adducts) were exclusively formed not only from azobenzenes (diaryldiazenes) but also from dialkyl azodicarboxylates. This method is also applicable to γ-alkylated or γ-phenylated propargylic bromides, providing the desired propargylated products only.

azo compounds - barium - hydrazine - propargylation - propargylic bromides

References and Notes

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