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Updated: Aug 2, 2026

Metal-free Synthesis of Ynones from Acyl Chlorides and Potassium Alkynyltrifluoroborate Salts
Published on: February 24, 2015
A novel, stereoselective silyl-directed Stevens [1,2]-shift of ammonium ylides
1Department of Chemistry, University of Utah, 315 S. 1400 East, Rm. 2020, Salt Lake City, Utah 84112-0850, USA.
Abstract:
[reaction: see text] The silyl group of 2-silylpyrrolidines such as 1 plays several critical roles: a stereochemical control element in a facially selective carbenoid addition to the ring nitrogen, a stereochemical "placeholder" during regioselective 1,2-migration with retention by the resulting spirocyclic ammonium ylide, and a hydroxyl surrogate for an eventual stereoselective Fleming-Tamao oxidation. This chemistry represents a novel use of the Stevens rearrangement and offers a short, enantioselective route to hydroxylated quinolizidines such as 3 from Boc-pyrrolidine.
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