Le Du, EliottDuhail, ThibautWodrich, Matthew D.Scopelliti, RosarioFadaei-Tirani, FarzanehAnselmi, ElsaMagnier, EmmanuelWaser, Jerome2021-06-192021-06-192021-06-192021-06-0410.1002/chem.202101475https://infoscience.epfl.ch/handle/20.500.14299/179219WOS:000657824000001Ethynylbenziodoxol(on)e (EBX) cyclic hypervalent iodine reagents have become popular reagents for the alkynylation of radicals and nucleophiles, but only offer limited possibilities for further structure and reactivity fine-tuning. Herein, the synthesis of new N-heterocyclic hypervalent iodine reagents with increased structural flexibility based on amide, amidine and sulfoximine scaffolds is reported. Solid-state structures of the reagents are reported and the analysis of the I-C-alkyne bond lengths allowed assessing the trans-effect of the different substituents. Molecular electrostatic potential (MEP) maps of the reagents, derived from DFT computations, revealed less pronounced sigma-hole regions for sulfonamide-based compounds. Most reagents reacted well in the alkynylation of beta-ketoesters. The alkynylation of thiols afforded more variable yields, with compounds with a stronger sigma-hole reacting better. In metal-mediated transformations, the N-heterocyclic hypervalent iodine reagents gave inferior results when compared to the O-based EBX reagents.Chemistry, MultidisciplinaryChemistryalkynyl transferdensity functional calculationsheterocycleshypervalent iodinesulfoximineacid-catalyzed rearrangementcrystal-structureoxy-alkynylationchemistryebxbenziodazolestransfunctionalizationalkenesindoletext::journal::journal article::research article