Issue 20, 2023

Mechanistic studies on catalytic alkane oxidation by Murahashi's O2/copper(ii)/aldehyde system

Abstract

Mechanistic studies on catalytic alkane hydroxylation by Murahashi's O2/copper(II)/aldehyde system have been conducted to show that the autoxidation of an aldehyde (RCHO) by an O2 generating acyl radical intermediate (RC(O)˙) is involved as an initiation step of the catalytic cycle. The generated RC(O)˙ is trapped by O2 to give an acylperoxyl radical intermediate RC(O)OO˙, which may react with another RCHO to generate an adduct intermediate RC(O)OOC(R)(H)O˙. The following O–O bond homolytic cleavage of this intermediate will give acyloxyl intermediate RC(O)O˙ and RCOOH, in which the former acts as a reactive species for hydrogen atom abstraction (HAA) from alkane substrates (R1R2CH2; R1 and R2 are alkyl groups or hydrogen atoms), giving R1R2CH˙. The generated R1R2CH˙ reacts with O2 to generate alkylperoxyl radical intermediate R1R2CHOO˙, which then undergoes the Russell reaction to give R1R2CHOH (alcohol) and R1R2C[double bond, length as m-dash]O (ketone) in a 1 : 1 ratio as the oxidation products. The acyloxyl intermediate RC(O)O˙ also reacts with RCHO to give carboxylic acid RC(O)OH and RC(O)˙, constructing the catalytic cycle. The role of copper(II) ions in the above catalytic process is also investigated using a series of copper(II) complexes. Furthermore, Murahashi's system was adopted in the catalytic oxidation of methane.

Graphical abstract: Mechanistic studies on catalytic alkane oxidation by Murahashi's O2/copper(ii)/aldehyde system

Supplementary files

Article information

Article type
Paper
Submitted
07 Jūl. 2023
Accepted
18 Jūl. 2023
First published
25 Aug. 2023

Catal. Sci. Technol., 2023,13, 5859-5867

Author version available

Mechanistic studies on catalytic alkane oxidation by Murahashi's O2/copper(II)/aldehyde system

K. Yamaguchi, Y. Uemura, H. Sugimoto, R. Ito, Y. Morimoto and S. Itoh, Catal. Sci. Technol., 2023, 13, 5859 DOI: 10.1039/D3CY00944K

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements