23 June 2024

Green Chemistry in Organic Synthesis

Author detail:

Fiza Urooj, Aisha Ghaffar

Department of Chemistry, University Of Agriculture Faisalabad, Sub-Campus Toba Tek Singh

Introduction

Green chemistry is related to sustainable chemistry and circular chemistry. Green chemistry concentrates on how chemistry affects the environment, including ways to reduce the use of fossil fuels and develop technical solutions to stop pollution, whereas ecological chemistry focuses on how polluting chemicals affect the surroundings.

History:

Throughout the 1990s, as concerns about chemical exposure and resource depletion gained traction, a range of already present theories and research initiatives (including atom economics and catalysis) gave rise to the field of green chemistry. Green chemistry originated in Europe and the US because of a change in the approaches taken to solving environmental problems. Rather than focusing solely on command and control regulations and lowering emission levels at the “end of the pipe,” scientists are now actively preventing pollution by designing innovative production technologies (Chen et al., 2020).

The term “green chemistry” was created by the scientists Paul Anastas along John Warner, who also created its twelve guiding principles. Ryoji Noyori distinguished three significant advancements in green chemistry in 2005: hydrogen in asymmetric synthesis, aqueous hydrogen peroxide for clean oxidations, and supercritical carbon dioxide as a green solvent. Through its financing, professional coordination, and pollution prevention initiatives, the Environmental Protection Agency (EPA) in the United States was a major early proponent of green chemistry. At the same time, in the UK, experts at the University of York helped to start the journal Green Chemistry and form the Green Chemistry Link through the Royal Institute of Chemistry.

THE CONCEPT OF GREEN CHEMISTRY

The concept of “green chemistry” initially developed in the United States as a vast scientific initiative. It was the outcome of multidisciplinary cooperation among university research groups, and independent research groups, including scientific societies and federal organizations, each of which members has a program focused on minimizing pollution levels in the environment. A new approach to the synthesis, processing, and use of chemicals is referred to as “green chemistry,” which aims to reduce the threats to public health and environmental degradation.

Atom Economy

Designing synthetic processes so that every product involved in the chain reaction ends up in the finished product is a good idea (Coppola, Pillitteri, Van der Eycken, You, & Sharma, 2022). Worldwide, chemists regard a reaction as “perfect” if the yield reaches 90% or higher. But there’s a chance that this response might produce a lot of waste. Trost created the idea of the “atom economy,” which is illustrated as follows: % atom economy is equal to (the FW of the reacting substances in the reaction) / (FW of each atom used).

Designing Safer Products

Products should be developed with the environment and human health in mind. Thalidomide is an ordinary instance of a hazardous medication; it was first released in West Germany in 1961. Pregnant women were prescribed this medication to prevent nausea and vomiting. Babies with phocomelia, a disorder characterized by abnormally small limbs with toes emerging from their pelvis and arms that resemble flippers, were born to pregnant mothers who had taken the medicine. Some babies have defective internal organs, such as unsegmented big or small intestines, or problems related to the eyes and ears. This medication is currently prescribed for the treatment of multiple myeloma patients as well as the acute management of erythema nodosum leprosum cutaneous symptoms.

Green chemistry describes a novel approach to the synthesis, processing, and use of chemicals in a method that reduces risks to human health and the environment. This fresh technique is sometimes referred to as:

  1. Atom economy
  2. Clean Chemistry
  3. Environmentally friendly chemistry
  4. By design, benign chemical

The design of chemical products and processes to reduce or completely do away with the usage and production of hazardous compounds is known as “green chemistry”.  Water is the medium used in this relatively new field of chemistry for in-lab chemical reactions. A solvent is the medium in which chemical reactions are often conducted. An instance of noncompliance is reactions that occur in the gas phase, without the requirement for a medium. There are instances when chemical reactions are carried out neatly. To be more precise, a solvent is required when the reactive components are combined and reacted. In green chemistry, this is one technique used to prevent pollution and the potentially harmful effects of volatile solvents. To reduce waste and make use of renewable resources, green chemistry is a chemical philosophy that is applied to analytical, physical, organic, inorganic, and biochemical.

Green chemistry in day-to-day life:

Perchloroethylene (PERC) is a solvent that is frequently used in green dry cleaning of clothing. PERC, which pollutes water in the ground and is thought to be carcinogenic, is now known. A technique known as  Micell technology, created by James McClain, Timothy Romark, and Joseph De Simons, replaced PERC in dry cleaning by using liquid CO2 and a surfactant. Using this method, dry cleaning machines have recently been developed. A metal cleaning solution called Micell Technology has also been developed, doing away with the requirement for halogenated solvents by using CO2 and a surfactant.

Applications of Green Chemistry:

Using chemical research and production in a sustainable, safe, and environmentally friendly manner that uses the least resources and energy and generates little to no waste is known as “green chemistry.” Green chemistry applications include the use of green methods in commerce, developing drugs, agriculture, and other fields. The realization that improper chemical product creation, processing, usage, and disposal might have negative effects is the first step toward practicing green chemistry. Instead of being an economic drag on profits and regressive, green chemistry aims to protect the environment while boosting revenues and encouraging innovation.

The chemical, pharmaceuticals, paper, polymer, apparel, and color sectors frequently employ green chemistry. It is also crucial for the development of new methods for making fuel cells, solar cells, and electrodes for energy storage, as well as other energy-related disciplines. Green chemistry has extensive applications in nanomaterials and nanoscience. Green chemistry’s main objective is to minimize or completely eradicate garbage in the chemical sector, which has sparked the creation of several green “next-generation” catalysts (Sheldon, 2016).

Conclusion:

As previously said, the goal of green chemistry was to reduce the quantity of hazardous materials utilized in the production and consumption of chemical products. It is well known that while developing a green chemical process, it is not possible to simultaneously meet the criteria of all 12 process principles. However, it tries its best to combine as many ideas as possible into a few procedures related to synthesis. The goals of green chemistry, which include environmental preservation and economic prosperity, can be achieved through various methods. For example, chemical products may be designed to break down into innocuous byproducts instead of remaining in the atmosphere after fulfilling their intended function. Green chemistry’s main goal is to satisfy societal demands without endangering or exhausting the planet’s natural resources. The use of green chemical techniques can contribute to environmental preservation. On the other hand, implementing the twelve green chemical principles will help to finally clear the path to a more favorable future. Green chemistry is insufficient to address the pressing environmental issues that have had an impact on the modern era.

References

Chen, T.-L., Kim, H., Pan, S.-Y., Tseng, P.-C., Lin, Y.-P., & Chiang, P.-C. (2020). Implementation of green chemistry principles in circular economy system towards sustainable development goals: Challenges and perspectives. Science of the Total Environment, 716, 136998.

Coppola, G. A., Pillitteri, S., Van der Eycken, E. V., You, S.-L., & Sharma, U. K. (2022). Multicomponent reactions and photo/electrochemistry join forces: atom economy meets energy efficiency. Chemical Society Reviews, 51(6), 2313-2382.

Sheldon, R. A. (2016). Engineering a more sustainable world through catalysis and green chemistry. Journal of The Royal Society Interface, 13(116), 20160087.

 

 

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