title: Mechanism of Oxidative Amidation of Nitroalkanes with Oxygen and Amine Nucleophiles by Using Electrophilic Iodine.
abstract: Recently, we developed a direct method to oxidatively convert primary nitroalkanes into amides that entailed mixing an iodonium source with an amine, base, and oxygen. Herein, we systematically investigated the mechanism and likely intermediates of such methods. We conclude that an amine-iodonium complex first forms through N-halogen bonding. This complex reacts with aci-nitronates to give both α-iodo- and α,α-diiodonitroalkanes, which can act as alternative sources of electrophilic iodine and also generate an extra equimolar amount of I(+) under O2. In particular, evidence supports α,α-diiodonitroalkane intermediates reacting with molecular oxygen to form a peroxy adduct; alternatively, these tetrahedral intermediates rearrange anaerobically to form a cleavable nitrite ester. In either case, activated esters are proposed to form that eventually reacts with nucleophilic amines in a traditional fashion.
authors.affiliation: Department of Chemistry, Graduate School of Science, Tohoku University, Aza Aramaki, Aoba-ku, Sendai, 980-8578, Japan.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: School of Chemistry, University of Lincoln, Brayford Pool, Lincoln, LN6 7TS, UK.
authors.forename: Martin J
authors.identifier: http://orcid.org/0000-0003-2556-2029
authors.initials: MJ
authors.lastname: Lear
authors.affiliation: Research and Analytical Center for Giant Molecules, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
authors.forename: Eunsang
authors.initials: E
authors.lastname: Kwon
authors.affiliation: Department of Chemistry, Graduate School of Science, Tohoku University, Aza Aramaki, Aoba-ku, Sendai, 980-8578, Japan. yhayashi@m.tohoku.ac.jp.
authors.forename: Yujiro
authors.initials: Y
authors.lastname: Hayashi
mesh_terms: D000473:Alkanes / Q000737:chemistry*; D000577:Amides / Q000737:chemistry*; D000588:Amines / Q000737:chemistry*; D007454:Iodides / Q000737:chemistry*; D007455:Iodine / Q000737:chemistry*; D009574:Nitro Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*
chemical_list: D000473:Alkanes; D000577:Amides; D000588:Amines; D007454:Iodides; D009574:Nitro Compounds; D007455:Iodine; D010100:Oxygen
keywords: amides; iodine; peroxides; radicals; umpolung