title: A discrete {Co4(μ3-OH)4}(4+) cluster with an oxygen-rich coordination environment as a catalyst for the epoxidation of various olefins.
abstract: Using the sterically hindered terphenyl-based carboxylate, the tetrameric Co(ii) complex [Co4(μ3-OH)4(μ-O2CAr(4F-Ph))2(μ-OTf)2(Py)4] () with an asymmetric cubane-type core has been synthesized and fully characterized by X-ray diffraction, UV-vis spectroscopy, and electron paramagnetic resonance spectroscopy. Interestingly, the cubane-type cobalt cluster with 3-chloroperoxybenzoic acid as the oxidant was found to be very effective in the epoxidation of a variety of olefins, including terminal olefins which are more challenging targeting substrates. Moreover, this catalytic system showed a fast reaction rate and high epoxide yields under mild conditions. Based on product analysis and Hammett studies, the use of peroxyphenylacetic acid as a mechanistic probe, H2(18)O-exchange experiments, and EPR studies, it has been proposed that multiple reactive cobalt-oxo species Co(V)[double bond, length as m-dash]O and Co(IV)[double bond, length as m-dash]O were involved in the olefin epoxidation.
authors.affiliation: Department of Fine Chemistry, Seoul National University of Science and Technology, Seoul 139-743, Korea. ohno801126@nate.com chealkim@seoultech.ac.kr.
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Department of Chemistry, College of Natural Sciences, Kookmin University, 861-1 Jeoungnung-dong, Seongbuk-gu, Seoul 136-702, Korea. yoona@kookmin.ac.kr.
authors.forename: Namseok
authors.initials: N
authors.lastname: Kim
authors.affiliation: Department of Fine Chemistry, Seoul National University of Science and Technology, Seoul 139-743, Korea. ohno801126@nate.com chealkim@seoultech.ac.kr.
authors.forename: Myoung Mi
authors.initials: MM
authors.lastname: Lee
authors.affiliation: Department of Fine Chemistry, Seoul National University of Science and Technology, Seoul 139-743, Korea. ohno801126@nate.com chealkim@seoultech.ac.kr.
authors.forename: Young Dan
authors.initials: YD
authors.lastname: Jo
authors.affiliation: Department of Fine Chemistry, Seoul National University of Science and Technology, Seoul 139-743, Korea. ohno801126@nate.com chealkim@seoultech.ac.kr.
authors.forename: Jeong Mi
authors.initials: JM
authors.lastname: Bae
authors.affiliation: Department of Fine Chemistry, Seoul National University of Science and Technology, Seoul 139-743, Korea. ohno801126@nate.com chealkim@seoultech.ac.kr.
authors.forename: Min Young
authors.initials: MY
authors.lastname: Hyun
authors.affiliation: Department of Chemistry, College of Natural Sciences, Kookmin University, 861-1 Jeoungnung-dong, Seongbuk-gu, Seoul 136-702, Korea. yoona@kookmin.ac.kr.
authors.forename: Sungho
authors.initials: S
authors.lastname: Yoon
authors.affiliation: Department of Fine Chemistry, Seoul National University of Science and Technology, Seoul 139-743, Korea. ohno801126@nate.com chealkim@seoultech.ac.kr.
authors.forename: Cheal
authors.initials: C
authors.lastname: Kim