Mild and highly efficient transfer hydrogenation of aldehyde and ketone catalyzed by rubidium phosphate

【摘要】 Rubidium phosphate can be more conveniently obtained by extracting trace Rb+ from the salt lake brine. Rb₃PO₄ was found to be an excellent heterogeneous catalyst for transfer hydrogenation. Rb₃PO₄ lost 70% of its active sites after adsorbing water, but the remaining was not affected. The reductions of aldehydes and ketones, when promoted by Rb₃PO₄, were allowed at room temperature. The activities of substrates at room temperature followed a descending order of 2,6-dichlorobenzaldehyde> 4-bromobenzaldehyde>benzaldehyde>acetophenone>anisaldehyde>butanone. A new catalytic cycle postulating a six-membered cyclic transition state for the reductions of aldehydes and ketones was proposed. These results exploited the catalytic usage of Rb₃PO₄ and worth in industrial application.更多还原

【Abstract】 Rubidium phosphate can be more conveniently obtained by extracting trace Rb+ from the salt lake brine. Rb₃PO₄ was found to be an excellent heterogeneous catalyst for transfer hydrogenation. Rb₃PO₄ lost 70% of its active sites after adsorbing water, but the remaining was not affected. The reductions of aldehydes and ketones, when promoted by Rb₃PO₄, were allowed at room temperature. The activities of substrates at room temperature followed a descending order of 2,6-dichlorobenzaldehyde> 4-bromobenzaldehyde>benzaldehyde>acetophenone>anisaldehyde>butanone. A new catalytic cycle postulating a six-membered cyclic transition state for the reductions of aldehydes and ketones was proposed. These results exploited the catalytic usage of Rb₃PO₄ and worth in industrial application.更多还原