The synthesis of a crystalline ethynyl-1,2-benziodoxol-3(1H)-one (EBX)−acetonitrile complex is described. EBX has been widely used as an active species for a variety of reactions; however, its high instability has so far prevented its isolation. The EBX−acetonitrile is self-assembled into a double-layered honeycomb structure through weak hypervalent iodine secondary interactions and hydrogen bonding. The N-ethynylation of a variety of sulfonamides using the EBX− acetonitrile complex as a substrate under mild conditions is also described.

An ortho‐substituted ether‐oxygen‐coordinated pseudocyclic iodosylbenzene‐trifluoroacetic acid (pcISB‐TFA) complex was synthesized and characterized by X‐ray crystallographic analysis. TFA suppresses the disproportionation by both coordination of the oxygen atom to the iodine(III) center through secondary bonding and by hydrogen bonding to the oxygen anion. This bench‐stable reagent is highly soluble in common organic solvents and reacts with various organic substrates under mild reaction conditions to give the corresponding products in good yields.

The synthesis of cis-β-amidevinyl benziodoxolones from the ethynyl benziodoxolone–chloroform complex and sulfonamides is reported. Evidence indicates that highly reactive unsubstituted ethynyl benziodoxolone undergoes Michael addition of sulfonamides, including sterically demanding acyclic amino acid derivatives. The synthesis of selectively deuterated cis-β-amidevinyl benziodoxolones and investigation of ethynyl-λ3-iodane reactivity are also described.

The stereoselective synthesis of cis-β-phenoxyvinyl benziodoxolones (cis-β-phenol-VBXs) from an ethynyl benziodoxolone-acetonitrile complex (EBX-MeCN) and various phenols is reported herein. The reaction tolerates different phenol derivatives, including complex natural products, and can be conducted under mild conditions. The synthesis was performed in an aqueous solvent in the absence and presence of a catalytic amount of a base. Selectively mono-and di-deuterated cis-β-phenol-VBXs were also prepared. cis-β-Phenol-VBXs were stereospecifically derivatized to cis-alkynylvinyl ethers and cis-iodovinyl ethers without loss of stereoselectivity or reduction in the deuterium/hydrogen ratio.