A researcher from the Leibniz Institute for Catalysis in Rostock has pioneered novel techniques for synthesizing drug precursors using catalysts composed of iron, manganese, and cobalt.
In a recent publication in the journal Chemical Science, Johannes Fessler elucidates how each of these three chemical elements holds promise in replacing numerous noble metals conventionally utilized in organic chemistry for catalyzing fine chemicals.
Fessler exemplifies this advancement by outlining the creation of a complex active ingredient candidate derived from pyrrole, a ubiquitous drug precursor. Employing an acid-tolerant homogeneous iron catalyst at ambient temperature enables the transformation of “basic starting materials” into the desired compound.
The term “homogeneous” catalysis denotes a process where all components—catalyst, solvent, product, and by-product—are dissolved within a single reaction vessel. Consequently, these components necessitate separation, purification, and preparation after each reaction step.
“Eliminating even one of these procedural steps significantly reduces both time and resource consumption while minimizing waste,” remarked Fessler in a press release.
This efficiency was notably demonstrated in the pyrrole reaction through a sequential reaction cascade.
Transitioning towards a Climate-Neutral Chemical Industry The substitution of noble metals with iron and analogous elements has emerged as an appealing avenue for research.
“The imperative for climate-neutral, sustainable practices extends to the chemical industry, alongside other sectors,” affirmed the researcher.
Given its abundant presence, comprising 5% of the Earth’s crust, iron offers particular promise. Following iron and titanium, manganese ranks as the third most prevalent transition metal globally.
Nevertheless, the historical underutilization of base metals in organic chemistry is not arbitrary.
“Base metals often exhibit inferior stability in catalytic processes compared to noble metal catalysts,” elucidated Fessler. “Moreover, they typically necessitate high temperatures and pressures within the scope of my research.”
Yet, such harsh conditions risk compromising the intricate molecular structures essential for drug efficacy—referred to as functional groups within the molecule.
In this regard, the achievement lies in demonstrating how iron, manganese, and cobalt catalysts can sometimes operate under considerably milder reaction conditions compared to conventional methods. For instance, in the case of pyrrole synthesis, temperatures range between 20 and 30 degrees Celsius.
Furthermore, Fessler’s experiments unveiled another advantage of his methodology: the precise conversion of only the targeted molecules, minimizing the generation of by-products or waste—a characteristic termed “highly selective.”
The reliability of this approach was corroborated through the examination of various active ingredients and drug precursors, ensuring the activation of the correct molecular sites while preserving sensitive functional groups.
This rigorous testing spanned a spectrum of pharmaceuticals, including widely used cholesterol-lowering medications and blood pressure regulators.
