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Updated: Apr 25, 2026

A Protocol for Safe Lithiation Reactions Using Organolithium Reagents
Published on: November 12, 2016
Nickel-catalyzed substitution reactions of propargyl halides with organotitanium reagents
Qing-Han Li1, Jung-Wei Liao, Yi-Ling Huang
1Department of Chemistry, National Chung Hsing University, Taichung 402, Taiwan. hmgau@draagon.nchu.edu.tw.
Abstract:
A simple and mild catalytic coupling reaction of propargyl halides with organotitanium reagents is reported. The reaction of propargyl bromide with organo-titanium reagents mediated by NiCl2 (2 mol%) and PCy3 (4 mol%) in CH2Cl2 afforded coupling product allenes in good to excellent yields (up to 95%) at room temperature. However, NiCl2(PPh3)2 was the best catalyst for substituted propargyl halides to yield allenes or alkynes preferentially. On the basis of the experimental results, a possible catalytic cycle has been proposed.
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