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Updated: Aug 13, 2026

Metal-free Synthesis of Ynones from Acyl Chlorides and Potassium Alkynyltrifluoroborate Salts
Published on: February 24, 2015
Propargyl bromide as an excellent alpha-bromoacetone equivalent: convenient and new route to alpha-aroylacetones
Sakkarapalayam M Mahalingam1, Indrapal Singh Aidhen
1Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, India.
Abstract:
[reaction: see text] A variety of alpha-aroylacetones 4a-g have been prepared in excellent yields following a new protocol wherein alpha-aminonitriles 1a-g as the aryl acyl anion equivalents readily react with propargyl bromide as the alpha-bromoacetone equivalent. The alkylated product undergoes one-pot unmasking of the keto functionality along with Markovnikov's hydration of the terminal alkyne with CuSO4 x 5H2O in aqueous methanol at 60 degrees C to furnish the desired target in excellent isolated yields.
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