Highly Enantioselective Undirected Catalytic Hydroxylation of Benzylic CH2 Groups with H2O2 Full article
| Journal |
Journal of Catalysis
ISSN: 0021-9517 , E-ISSN: 1090-2694 |
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| Output data | Year: 2020, Volume: 390, Pages: 170-177 Pages count : 8 DOI: 10.1016/j.jcat.2020.08.005 | ||||
| Tags | Asymmetric catalysis; C-H activation; Desaturation; Hydrogen peroxide; Manganese oxidation | ||||
| Authors |
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| Affiliations |
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Funding (1)
| 1 | Russian Science Foundation | 20-13-00032 (АААА-А20-120071590003-2) |
Abstract:
Chiral bis-amine-bis-pyridine Mn complexes of the type [LMnII(OTf)2] (L is 2,2ʹ-bipyrrolidine derived chiral ligand, bearing trifluoroethoxy and methyl substituents), efficiently catalyze the enantioselective hydroxylation of organic substrates at benzylic CH2 positions with H2O2. The use of β-polyfluorinated alcohols instead of CH3CN as the reaction solvents enhances the yield of chiral secondary alcohol from 5–6% up to 50–70%. The enantiomeric purity of the alcohol can be further increased (up to 97% ee) by diluting the mixture with CH3CN at late stage, which facilitates stereoconvergent oxidative kinetic resolution of the alcohol formed. Using this one-pot sequential asymmetric hydroxylation/oxidative kinetic resolution approach, the oxidation of a series of 3,4-dihydrocoumarin derivatives and 3,4-dihydroquinolinone has been realized, affording the target 4-hydroxo compounds in 40–60% isolated yield and in up to 93% ee. Besides the 4-hydroxo derivatives, formation of 3,4-epoxidation and 3,4-desaturation byproducts has been observed in some cases, thus providing evidence for unprecedented substrate-dependent hydroxylase/desaturase/epoxidase reactivity of bis-amine-bis-pyridine Mn complexes.
Cite:
Ottenbacher R.V.
, Talsi E.P.
, Bryliakov K.P.
Highly Enantioselective Undirected Catalytic Hydroxylation of Benzylic CH2 Groups with H2O2
Journal of Catalysis. 2020. V.390. P.170-177. DOI: 10.1016/j.jcat.2020.08.005 WOS Scopus РИНЦ ANCAN OpenAlex
Highly Enantioselective Undirected Catalytic Hydroxylation of Benzylic CH2 Groups with H2O2
Journal of Catalysis. 2020. V.390. P.170-177. DOI: 10.1016/j.jcat.2020.08.005 WOS Scopus РИНЦ ANCAN OpenAlex
Dates:
| Submitted: | Jul 9, 2020 |
| Accepted: | Aug 3, 2020 |
| Published online: | Aug 12, 2020 |
| Published print: | Oct 1, 2020 |
Identifiers:
| Web of science: | WOS:000571126000002 |
| Scopus: | 2-s2.0-85089818642 |
| Elibrary: | 45402859 |
| Chemical Abstracts: | 2020:1687084 |
| Chemical Abstracts (print): | 173:534501 |
| OpenAlex: | W3048629394 |