title: cis-1,2-Aminohydroxylation of Alkenes Involving a Catalytic Cycle of Osmium(III) and Osmium(V) Centers: Os(V)(O)(NHTs) Active Oxidant with a Macrocyclic Tetradentate Ligand.
abstract: Catalytic activity of [Os(III)(OH)(H2O)(L-N4Me2)](PF6)2 (1: L-N4Me2 = N,N'-dimethyl-2,11-diaza-[3,3](2,6)pyridinophane) in 1,2-cis-aminohydroxylation of alkenes with sodium N-chloro-4-methylbenzenesulfonamide (chloramine-T) is explored. Simple alkenes as well as those containing several types of substituents are converted to the corresponding 1,2-aminoalcohols in modest to high yields. The aminoalcohol products have exclusively cis conformation with respect to the introduced -OH and -NHTs groups. The spectroscopic measurements including cold mass spectroscopic study of the reaction product of complex 1 and chloromine-T as well as density functional theory (DFT) calculations indicate that an oxido-aminato-osmium(V) species [Os(V)(O)(NHTs)(L-N4Me2)](PF6)2 (2) is an active oxidant for the aminohydroxylation. The DFT calculations further indicate that the reaction involves a [3 + 2] cycloaddition between 2 and alkene, and the regioselectivity in the aminohydroxylation of unsymmetrical alkenes is determined by the orientation that bears less steric hindrance from the tosylamino group, which leads to the energetically more preferred product isomer.
authors.affiliation: †Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Sugimoto
authors.affiliation: †Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Akine
authors.initials: A
authors.lastname: Mikami
authors.affiliation: †Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Kai
authors.affiliation: ‡Institute for Materials Chemistry and Engineering and International Research Center for Molecular System, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: P K
authors.initials: PK
authors.lastname: Sajith
authors.affiliation: ‡Institute for Materials Chemistry and Engineering and International Research Center for Molecular System, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Shiota
authors.affiliation: ‡Institute for Materials Chemistry and Engineering and International Research Center for Molecular System, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Yoshizawa
authors.affiliation: ¶Comprehensive Analysis Center, The Institute of Scientific and Industrial Research (ISIR), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0057, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Asano
authors.affiliation: ¶Comprehensive Analysis Center, The Institute of Scientific and Industrial Research (ISIR), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0057, Japan.
authors.forename: Takeyuki
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: †Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Shinobu
authors.initials: S
authors.lastname: Itoh
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D000586:Amination; D002384:Catalysis; D002700:Chloramines / Q000737:chemistry; D053138:Cyclohexenes / Q000737:chemistry; D006900:Hydroxylation; D008024:Ligands; D047028:Macrocyclic Compounds / Q000737:chemistry*; D008958:Models, Molecular; D009992:Osmium / Q000737:chemistry*; D016877:Oxidants / Q000737:chemistry*; D014105:Tosyl Compounds / Q000737:chemistry
chemical_list: D000475:Alkenes; D002700:Chloramines; D053138:Cyclohexenes; D008024:Ligands; D047028:Macrocyclic Compounds; D016877:Oxidants; D014105:Tosyl Compounds; C016300:chloramine-T; C052568:cyclohexene; D009992:Osmium; C037690:1-octene