Fluorobenziodoxole-BF3 Reagent for Iodo(III)etherification of Alkynes in Ethereal Solvent
Jinkui Chai1,2, Wei Ding1, Junliang Wu2
1Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore.
Abstract:
A combination of fluorobenziodoxole (FBX) and BF3 ⋅ OEt2 in cyclopentyl methyl ether promotes regio- and stereoselective addition of benziodoxole and methoxy groups to alkynes. This difunctionalization reaction tolerates a variety of functionalized internal and terminal alkynes to afford trans-β-alkoxyvinylbenziodoxoles, which represent versatile precursors to stereochemically well-defined multisubstituted vinyl ethers. The reaction is proposed to involve cleavage of the I-F bond of FBX by BF3 , followed by electrophilic activation of the alkyne by the resulting cationic IIII species that triggers the nucleophilic addition of the ethereal oxygen.
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