Sustainable Catalysis Breakthrough Catalyst Turns Methane into Bioactive Compounds

Researchers have developed an iron-based catalyst that tames the reactivity of methane, paving the way for natural gas to become a sustainable raw material for high-value chemicals, including pharmaceuticals.

Natural gas is primarily composed of methane, ethane, and propane. While it is widely burned for energy, producing greenhouse gas emissions, scientists and industries have long sought ways to directly convert these hydrocarbons into valuable chemicals. However, their extreme stability and low reactivity have posed a formidable challenge, limiting their use as sustainable feedstocks for the chemical industry.

Now, a team led by Martín Fañanás at the Centre for Research in Biological Chemistry and Molecular Materials (Ciqus) at the University of Santiago de Compostela has developed a groundbreaking method to transform methane and other natural gas components into versatile “building blocks” for synthesizing high-demand products, such as pharmaceuticals. Published in Science Advances, this advance represents a critical leap toward a more sustainable and circular chemical economy.

For the first time, the Ciqus team successfully synthesized a bioactive compound — dimestrol, a non-steroidal estrogen used in hormone therapy — directly from methane. This achievement demonstrates the potential of their methodology to create complex, high-value molecules from a simple, abundant, and low-cost raw material.

Taming Free Radicals to Unlock New Chemical Pathways

The team’s strategy centers on a reaction called allylation, which involves attaching a small chemical “handle” (an allyl group) to the gas molecule. This handle serves as a versatile anchor, enabling subsequent steps to build a wide range of final products — from pharmaceutical active ingredients to everyday chemicals. The main hurdle had been the catalytic system’s tendency to produce unwanted chlorination byproducts, derailing the process.

Nanoscale Catalyst Behavior

Atomic Insights Could Boost Chemical Manufacturing Efficiency

To overcome this obstacle, the team engineered a tailor-made supramolecular catalyst. “The core of this breakthrough lies in designing a catalyst based on a tetrachloroferrate anion stabilized by collidinium cations, which effectively modulates the reactivity of the radical species generated in the reaction medium,” explains Prof. Fañanás. “The formation of an intricate network of hydrogen bonds around the iron atom sustains the photocatalytic reactivity required to activate the alkane, while simultaneously suppressing the catalyst’s tendency to undergo competing chlorination reactions. This creates an optimal environment for the selective allylation reaction to proceed.”

Beyond its effectiveness, the method stands out for its sustainability. It uses iron — a cheap, abundant, and far less toxic metal than the precious metals typically used in catalysis — and operates under mild temperature and pressure conditions, powered by LED light. This significantly reduces both environmental impact and energy costs.

This work is part of a broader research line funded by the European Research Council (ERC), focused on upgrading the main components of natural gas. In a complementary advance published in Cell Reports Physical Science, the same team presented a method to directly couple these gases with acid chlorides, yielding industrially relevant ketones in a single step. Both studies, based on photocatalytic strategies, position Ciqus as a leader in developing innovative chemical solutions to harness abundant raw materials.

Transforming Natural Gas into Versatile Chemical Intermediates

The ability to convert natural gas into versatile chemical intermediates opens up new possibilities for industry, laying the foundation to gradually replace petrochemical sources with more sustainable alternatives. This cutting-edge research is made possible by the excellence environment at Ciqus, which holds the CIGUS accreditation from the Galician government, recognizing the quality and impact of its research. The center receives crucial financial support from the European Union through the Galicia Feder 2021-2027 Program, enabling scientific advances with potential for transfer and socioeconomic impact.

Original Article: Attenuated LMCT photocatalysis enables C—H allylation of methane and other gaseous alkanes; Science Advances; DOI:10.1126/sciadv.aea0783

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