title: Enolonium Species-Umpoled Enolates.
abstract: Enolonium species/iodo(III)enolates of carbonyl compounds have been suggested to be intermediates in a wide variety of hypervalent iodine induced chemical transformations of ketones, including α-C-O, α-C-N, α-C-C, and α-carbon-halide bond formation, but they have never been characterized. We report that these elusive umpoled enolates may be made as discrete species that are stable for several minutes at -78 °C, and report the first spectroscopic identification of such species. It is shown that enolonium species are direct intermediates in C-O, C-N, C-Cl, and C-C bond forming reactions. Our results open up chemical space for designing a variety of new transformations. We showcase the ability of enolonium species to react with prenyl, crotyl, cinnamyl, and allyl silanes with absolute regioselectivity in up to 92 % yield.
authors.affiliation: Department of Chemical Sciences, Ariel-University, 40700, Ariel, Israel.
authors.forename: Shlomy
authors.initials: S
authors.lastname: Arava
authors.affiliation: Department of Chemical Sciences, Ariel-University, 40700, Ariel, Israel.
authors.forename: Jayprakash N
authors.initials: JN
authors.lastname: Kumar
authors.affiliation: Department of Chemical Sciences, Ariel-University, 40700, Ariel, Israel.
authors.forename: Shimon
authors.initials: S
authors.lastname: Maksymenko
authors.affiliation: Computational Chemistry Unit, Department of Chemical Research Support, Weizmann Institute of Science, 7610001, Rehovot, Israel.
authors.forename: Mark A
authors.identifier: 0000-0001-9774-2358
authors.initials: MA
authors.lastname: Iron
authors.affiliation: Department of Chemical Sciences, Ariel-University, 40700, Ariel, Israel.
authors.forename: Keshaba N
authors.initials: KN
authors.lastname: Parida
authors.affiliation: Institute of Chemistry, Technical University of Denmark, 2400-Kgs, Lyngby, Denmark.
authors.forename: Peter
authors.identifier: 0000-0001-7175-3796
authors.initials: P
authors.lastname: Fristrup
authors.affiliation: Department of Chemical Sciences, Ariel-University, 40700, Ariel, Israel.
authors.forename: Alex M
authors.identifier: 0000-0001-7790-4129
authors.initials: AM
authors.lastname: Szpilman
keywords: allylation; enolonium species; ketones; polarity inversion; umpolung