Selective C-H Functionalization of Methane and Ethane by a Molecular Sb^V Complex

Area of Science:

• Organometallic Chemistry
• Catalysis
• C-H Activation

Background:

• Selective C-H functionalization of methane and ethane is difficult due to strong nonpolar bonds.
• Existing methods often lack selectivity or require harsh conditions.

Purpose of the Study:

• To develop a molecular homogeneous catalyst for selective C-H functionalization of methane and ethane.
• To synthesize valuable trifluoroacetate esters from simple alkanes.

Main Methods:

• Computational prediction of a main-group p-block antimony(V) complex, Sb^V (TFA)₅.
• Experimental testing of the catalyst for C-H functionalization reactions at 110-180 °C.

Main Results:

• The Sb^V (TFA)₅ complex selectively functionalized C-H bonds of methane and ethane to mono/di-ol trifluoroacetate esters.
• Yields for ethane reached up to 60% with over 90% selectivity.
• Mechanism involves Sb^V-mediated C-H activation and subsequent functionalization of an Sb^V-alkyl intermediate.

Conclusions:

• Antimony(V) complexes can mediate selective C-H functionalization of light alkanes.
• This work provides a novel route for alkane valorization.
• Understanding the unique mechanism opens avenues for catalyst design.