Fluorobenziodoxole-BF3 reagent for Iodo(III)etherification of alkynes in ethereal solvent

• Main Authors: Chai, Jinkui, Ding, Wei, Wu, Junliang, Yoshikai, Naohiko
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2022
• Subjects: Science::Biological sciences::Biochemistry; Alkynes; Lewis Acid
• Online Access: https://hdl.handle.net/10356/155202
• Institution: Nanyang Technological University

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.