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Structure and Reactivity of N‐Heterocyclic Alkynyl Hypervalent Iodine Reagents
Author(s) -
Le Du Eliott,
Duhail Thibaut,
Wodrich Matthew D.,
Scopelliti Rosario,
FadaeiTirani Farzaneh,
Anselmi Elsa,
Magnier Emmanuel,
Waser Jerome
Publication year - 2021
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202101475
Subject(s) - hypervalent molecule , reagent , chemistry , reactivity (psychology) , combinatorial chemistry , iodine , nucleophile , iodine monochloride , sulfonamide , alkyne , organic chemistry , catalysis , medicine , alternative medicine , pathology
Ethynylbenziodoxol(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 σ‐hole regions for sulfonamide‐based compounds. Most reagents reacted well in the alkynylation of β‐ketoesters. The alkynylation of thiols afforded more variable yields, with compounds with a stronger σ‐hole reacting better. In metal‐mediated transformations, the N‐heterocyclic hypervalent iodine reagents gave inferior results when compared to the O‐based EBX reagents.