Ruthenaelectro-catalyzed C-H phosphorylation: ortho to para position-selectivity switch

Area of Science:

• Organometallic Chemistry
• Electrocatalysis
• Organic Synthesis

Background:

• Site-selective C-H bond activation in arenes remains a significant synthetic challenge.
• Traditional methods often generate substantial chemical redox waste.
• Developing sustainable catalytic systems for C-H functionalization is crucial.

Purpose of the Study:

• To develop an efficient and site-selective C-H phosphorylation method for arenes.
• To utilize electrocatalysis driven by the hydrogen evolution reaction (HER) for greener synthesis.
• To explore the scope and limitations of this novel catalytic system.

Main Methods:

• Ruthenium-catalyzed electrochemistry for C-H bond activation.
• Electrochemical hydrogen evolution reaction (HER) as the driving force.
• Density Functional Theory (DFT) for mechanistic investigation.

Main Results:

• Achieved expedient ruthenium-electrocatalyzed site-selective ortho-C-H phosphorylation of arenes.
• Demonstrated unprecedented ruthenium-electro-catalyzed para-C-H phosphorylation with high selectivity.
• Showcased broad substrate scope, tolerating N-heterocycles and phosphine oxides, including late-stage drug functionalization.

Conclusions:

• This electrocatalytic strategy offers a sustainable alternative, avoiding stoichiometric redox waste.
• The method provides high site-selectivity for both ortho- and para-C-H phosphorylation.
• DFT studies suggest a unique ruthenium(iii/iv/ii) catalytic cycle for the ortho-phosphorylation.