Natural gas is one of the most plentiful energy resources on Earth. It is made mostly of methane, along with ethane and propane. Today, it is primarily burned for heat and electricity, a process that releases greenhouse gases. For years, researchers and industry leaders have tried to find ways to convert these simple hydrocarbons directly into useful chemicals instead of burning them. The challenge is that methane and similar gases are extremely stable and do not react easily, which has limited their use as sustainable raw materials for manufacturing.
A research 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 now developed a new method to transform methane and other components of natural gas into versatile chemical “building blocks” that can be used to make high value products, including pharmaceuticals. The study, published in Science Advances, marks an important step toward a more sustainable and circular chemical economy.
In a landmark demonstration, the CiQUS team synthesized a bioactive compound directly from methane for the first time. The compound, dimestrol, is a non-steroidal estrogen used in hormone therapy. Producing such a complex molecule from methane highlights the potential of this approach to turn an abundant, inexpensive gas into sophisticated and commercially important chemicals.
Methane Activation and Selective Allylation
The researchers focused on a reaction known as allylation. This process attaches a small chemical fragment called an allyl group to a gas molecule, effectively giving it a functional “handle” (an allyl group) that chemists can build on in later steps. With this handle in place, the modified molecule can be transformed into a wide range of products, from pharmaceutical ingredients to common industrial chemicals.
One major obstacle was the tendency of the catalytic system to trigger unwanted chlorination reactions, which created byproducts and reduced efficiency. Controlling these side reactions was essential to making the process practical.
Custom Iron Catalyst Controls Free Radicals
To solve this problem, the team designed a specialized 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.”
In simpler terms, the catalyst carefully manages highly reactive radical intermediates so they drive the desired transformation without causing unwanted side reactions.
Sustainable Photocatalysis Using Iron and LED Light
Beyond its chemical precision, the method also stands out for its environmental advantages. It relies on iron, which is inexpensive, widely available, and far less toxic than the rare and precious metals often used in catalytic chemistry. The reaction runs under relatively mild temperatures and pressures and is powered by LED light. Together, these features reduce energy demands and environmental impact.
This discovery is part of a larger research effort supported by the European Research Council (ERC) aimed at upgrading the primary components of natural gas into more valuable chemicals. In related work published in Cell Reports Physical Science, the same group reported a method for directly combining these gases with acid chlorides to produce industrially important ketones in a single step. Both advances rely on photocatalysis and strengthen CiQUS’s position as a leader in developing innovative strategies to use abundant raw materials more effectively.
Toward a Circular Chemical Economy
Converting natural gas into flexible chemical intermediates could expand industrial options and gradually decrease reliance on traditional petrochemical feedstocks. The research benefits from the strong scientific environment at CiQUS, which holds the CIGUS accreditation from the Galician government in recognition of its research excellence and impact. The center also receives key funding from the European Union through the Galicia FEDER 2021-2027 Program, supporting scientific progress with clear potential for technology transfer and broader socioeconomic benefits.