Aryne Precursors for Selective Generation of 3-Haloarynes: Preparation and Application to Synthetic Reactions
Eito Yoshioka1, Kengo Kakigi1, Shouta Miyoshi1
1School of Pharmacy, Hyogo University of Health Sciences, Minatojima, Chuo-ku, Kobe 650-8530, Japan.
Abstract:
The synthesis and reaction of new 3-haloaryne precursors 2a-2h were studied. The ortho-(trimethylsilyl)aryl triflate precursors 2a-2h were prepared by a simple procedure involving O-trimethylsilylation and migration of a trimethylsilyl group followed by triflation. The remarkable feature of new precursors is the selective generation of 3-haloarynes by suppressing the competitive thia-Fries rearrangement, which is the problem in the reaction using the well-known 3-haloaryne precursors. The advantage of new precursor 2a over a typical precursor 1 was confirmed by the direct comparisons in several reactions. The application of precursors 2a-2h to the syntheses of heterocycles was also reported.
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