An efficient and convenient catalyst based on MnAl layered double oxide (Mn₂Al-LDO) has been developed for the aerobic oxidative transformations of 1,2-diols and alcohols under normal pressure without any additives. The excellent electron transfer ability and strong surface basic sites of the catalyst realize the oxidation primarily via two-electron transfer (TET), and minorly via single-electron transfer (SET) processes.

Abstract

An efficient and convenient MnAl layered double oxide (Mn₂Al-LDO) catalyst has been developed. Characterization results indicated that Mn₂Al-LDO exhibits an improved ability of electron transfer and increased surface strong basic sites on its surface compared to the layered double hydroxide (Mn₂Al-LDH) precursor and conventionally prepared Mn₂AlO_x. These characters endow the Mn₂Al-LDO with excellent catalytic performance in the aerobic oxidative cleavage of 1,2-diols under normal pressure without additives. Mechanistic studies demonstrate that both the two-electron transfer (TET) and single-electron transfer (SET) processes are included in the catalytic reaction, with the former being more prominent. The Mn₂Al-LDO catalytic system can tolerate a broad substrate scope, including monosubstituted 1,2-diols, internal 1,2-diols, primary alcohols, secondary alcohols, and various α-functionalized alcohols. Additionally, the Mn₂Al-LDO catalytic system also exhibits excellent catalytic stability and shows great potential for application in cascade transformations.