Solvent-Free and Catalyst-Free Hydroamination of 2‑Ethynylpyridine
Michael Le1, Thomas Troester1, Eleanor Cummings1
1University of St. Thomas, Department of Chemistry, 2115 Summit Ave., St. Paul, Minnesota 55105, United States.
Abstract:
Hydroamination has been a steadfast way to install amines onto relatively nonactivated carbon-carbon bonds for decades. The traditional hydroamination of aryl-alkynes requires high temperatures, significantly electron-deficient groups, or catalysts. This work demonstrates that proper alignment of alkynes and nitrogen atoms in pyridine rings allows for enhanced reactivity of hydroamination reactions and is stereoselective for the E-alkene. This was further confirmed by a competition reaction with diethynylpyrazine. The possibility of postsynthetic transformations, such as hydrogenation and alkylation, makes these materials promising nitrogen-rich precursors for other applications.
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