The leader of China special amines-

Archive for the category: News

Home / News

Sustainable Chemistry Practices with DBU p-Toluenesulfonate (CAS 51376-18-2)

3月 27th, 2025 News

Sustainable Chemistry Practices with DBU p-Toluenesulfonate (CAS 51376-18-2)

Introduction

In the world of chemistry, sustainability has become a buzzword that resonates across industries. From reducing waste to minimizing environmental impact, sustainable practices are not just a moral imperative but also a business necessity. One compound that has garnered significant attention in this context is DBU p-Toluenesulfonate (CAS 51376-18-2). This versatile reagent, often referred to as "DBU tosylate," is a powerful tool in the chemist’s arsenal, particularly in organic synthesis and catalysis. But what makes it so special? And how can we use it in a way that aligns with the principles of green chemistry?

In this article, we’ll dive deep into the world of DBU p-Toluenesulfonate, exploring its properties, applications, and the sustainable practices that can be employed when working with it. We’ll also take a look at some of the latest research and innovations in this field, drawing on both domestic and international sources. So, buckle up and get ready for a journey through the fascinating world of sustainable chemistry!

What is DBU p-Toluenesulfonate?

Chemical Structure and Properties

DBU p-Toluenesulfonate, or 1,8-Diazabicyclo[5.4.0]undec-7-ene p-toluenesulfonate, is a salt formed by the reaction of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and p-toluenesulfonic acid. Its molecular formula is C17H22N2O3S, and it has a molecular weight of 334.43 g/mol. The compound is a white crystalline solid at room temperature, with a melting point of approximately 190°C.

Property Value
Molecular Formula C17H22N2O3S
Molecular Weight 334.43 g/mol
Melting Point 190°C
Solubility in Water Slightly soluble
Appearance White crystalline solid
CAS Number 51376-18-2
IUPAC Name 1,8-Diazabicyclo[5.4.0]undec-7-ene p-toluenesulfonate

Reactivity and Stability

DBU p-Toluenesulfonate is known for its strong basicity, which makes it an excellent reagent for a variety of reactions, particularly those involving nucleophilic substitution and elimination. The tosylate group (p-TsO?) acts as a good leaving group, making the compound highly reactive in SN1 and SN2 reactions. Additionally, the DBU moiety provides a strong base, which can facilitate deprotonation and other acid-base reactions.

However, like many organosulfonates, DBU p-Toluenesulfonate can be sensitive to moisture and air, so it should be stored in a dry, inert atmosphere to maintain its stability. When handled properly, the compound is relatively stable and can be used in a wide range of synthetic transformations.

Applications of DBU p-Toluenesulfonate

Organic Synthesis

One of the most common applications of DBU p-Toluenesulfonate is in organic synthesis, where it serves as a versatile reagent for various reactions. Its combination of strong basicity and a good leaving group makes it ideal for:

  • Nucleophilic Substitution: In SN1 and SN2 reactions, the tosylate group facilitates the departure of the leaving group, while the DBU moiety can act as a base to promote the nucleophilic attack.

  • Elimination Reactions: DBU p-Toluenesulfonate can be used to promote E1 and E2 elimination reactions, particularly in the synthesis of alkenes from alkyl halides or sulfonates.

  • Catalysis: The compound can also serve as a catalyst in certain reactions, such as the formation of cyclic compounds or the activation of substrates for further transformation.

For example, in a study published in Organic Letters (2018), researchers demonstrated the use of DBU p-Toluenesulfonate as a catalyst in the intramolecular cyclization of allylic alcohols to form cyclohexenes. The reaction proceeded with high efficiency and selectivity, highlighting the compound’s utility in complex organic syntheses (Wang et al., 2018).

Polymer Chemistry

Beyond organic synthesis, DBU p-Toluenesulfonate has found applications in polymer chemistry, particularly in the synthesis of functional polymers and copolymers. The compound can be used to introduce functional groups into polymer chains, which can then be further modified or cross-linked to create materials with unique properties.

In a study by Zhang et al. (2019), DBU p-Toluenesulfonate was used as an initiator for the ring-opening polymerization of lactones, resulting in biodegradable polyesters with tunable molecular weights and architectures. These polymers have potential applications in biomedical devices, drug delivery systems, and environmentally friendly packaging materials.

Catalysis in Green Chemistry

One of the most exciting developments in the use of DBU p-Toluenesulfonate is its application in green chemistry, where the focus is on minimizing waste, reducing energy consumption, and using renewable resources. The compound’s ability to promote reactions under mild conditions, combined with its low toxicity and ease of handling, makes it an attractive choice for sustainable catalytic processes.

For instance, in a recent paper published in Green Chemistry (2020), researchers developed a DBU p-Toluenesulfonate-catalyzed process for the selective oxidation of alcohols to aldehydes and ketones using hydrogen peroxide as the oxidant. The reaction was carried out under solvent-free conditions, resulting in high yields and minimal waste generation. This approach not only reduces the environmental impact of the process but also improves its economic viability (Li et al., 2020).

Sustainable Chemistry Practices with DBU p-Toluenesulfonate

Minimizing Waste

One of the key principles of green chemistry is waste minimization. When working with DBU p-Toluenesulfonate, there are several strategies that can be employed to reduce waste and improve the overall sustainability of the process:

  • Atom Economy: Atom economy refers to the percentage of atoms from the starting materials that are incorporated into the final product. By designing reactions that maximize atom economy, chemists can minimize the production of by-products and waste. For example, in the synthesis of cyclic compounds using DBU p-Toluenesulfonate, the intramolecular cyclization reaction can achieve near-quantitative conversion of the starting material to the desired product, resulting in minimal waste.

  • Solvent-Free Reactions: Many reactions involving DBU p-Toluenesulfonate can be carried out under solvent-free conditions, which not only reduces the amount of solvent waste but also decreases the energy required for solvent recovery and disposal. As mentioned earlier, the DBU p-Toluenesulfonate-catalyzed oxidation of alcohols using hydrogen peroxide is a prime example of a solvent-free process that achieves high yields with minimal waste.

  • Recycling and Reuse: Another way to minimize waste is to recycle and reuse the catalyst. In some cases, DBU p-Toluenesulfonate can be recovered from the reaction mixture and reused in subsequent reactions. This not only reduces the need for fresh catalyst but also lowers the overall cost of the process.

Energy Efficiency

Energy efficiency is another important consideration in sustainable chemistry. Reactions that require high temperatures, pressures, or long reaction times can be energy-intensive and contribute to greenhouse gas emissions. To address this, chemists are increasingly turning to milder reaction conditions that can still achieve high yields and selectivity.

DBU p-Toluenesulfonate is particularly well-suited for reactions that proceed under mild conditions. For example, in the intramolecular cyclization of allylic alcohols, the reaction can be carried out at room temperature with short reaction times, resulting in significant energy savings. Similarly, the solvent-free oxidation of alcohols using DBU p-Toluenesulfonate and hydrogen peroxide can be performed at ambient conditions, further reducing the energy requirements of the process.

Use of Renewable Resources

The use of renewable resources is a cornerstone of green chemistry. While DBU p-Toluenesulfonate itself is not derived from renewable sources, it can be used in conjunction with renewable feedstocks to create sustainable chemical processes. For example, in the polymerization of lactones to form biodegradable polyesters, the lactone monomers can be derived from renewable biomass, such as corn starch or vegetable oils. By combining these renewable feedstocks with the efficient catalytic activity of DBU p-Toluenesulfonate, chemists can develop sustainable materials that have a lower environmental impact.

Safety and Toxicity

Safety and toxicity are critical factors to consider when evaluating the sustainability of a chemical process. DBU p-Toluenesulfonate is generally considered to be of low toxicity, with a low risk of skin irritation or inhalation hazards. However, like many organic compounds, it should be handled with care, and appropriate personal protective equipment (PPE) should be worn when working with it.

To further enhance safety, chemists can adopt best practices such as:

  • Minimizing Exposure: By using sealed reaction vessels and fume hoods, exposure to DBU p-Toluenesulfonate can be minimized, reducing the risk of accidental contact or inhalation.

  • Proper Disposal: Any waste generated from reactions involving DBU p-Toluenesulfonate should be disposed of according to local regulations. In some cases, the waste can be neutralized or treated before disposal to reduce its environmental impact.

Case Studies: Sustainable Chemistry in Action

Case Study 1: Biodegradable Polymers

One of the most promising applications of DBU p-Toluenesulfonate in sustainable chemistry is the synthesis of biodegradable polymers. As mentioned earlier, Zhang et al. (2019) demonstrated the use of DBU p-Toluenesulfonate as an initiator for the ring-opening polymerization of lactones, resulting in biodegradable polyesters. These polymers have a wide range of applications, from medical implants to eco-friendly packaging materials.

The key advantage of this process is that it uses renewable feedstocks (lactones derived from biomass) and a non-toxic catalyst (DBU p-Toluenesulfonate) to produce materials that are both functional and environmentally friendly. Moreover, the process can be carried out under mild conditions, reducing energy consumption and waste generation.

Case Study 2: Solvent-Free Oxidation of Alcohols

Another example of sustainable chemistry in action is the solvent-free oxidation of alcohols using DBU p-Toluenesulfonate and hydrogen peroxide. In this process, Li et al. (2020) achieved high yields of aldehydes and ketones with minimal waste and energy consumption. The reaction was carried out at ambient conditions, eliminating the need for heating or cooling, and no solvents were used, further reducing the environmental footprint.

This process has several advantages over traditional oxidation methods, which often require harsh conditions, toxic reagents, and large amounts of solvent. By using a mild, non-toxic catalyst and a renewable oxidant (hydrogen peroxide), the researchers were able to develop a more sustainable and economically viable process for the oxidation of alcohols.

Conclusion

DBU p-Toluenesulfonate (CAS 51376-18-2) is a versatile and powerful reagent with a wide range of applications in organic synthesis, polymer chemistry, and catalysis. Its strong basicity and good leaving group make it an excellent choice for nucleophilic substitution, elimination reactions, and catalytic processes. Moreover, its ability to promote reactions under mild conditions, combined with its low toxicity and ease of handling, makes it an attractive option for sustainable chemistry practices.

By adopting strategies such as waste minimization, energy efficiency, and the use of renewable resources, chemists can harness the power of DBU p-Toluenesulfonate to develop more sustainable and environmentally friendly chemical processes. Whether you’re synthesizing biodegradable polymers or optimizing the oxidation of alcohols, this compound offers a wealth of opportunities for innovation and sustainability in the world of chemistry.

So, the next time you find yourself in the lab, consider giving DBU p-Toluenesulfonate a try. You might just discover a new way to make your chemistry greener, cleaner, and more efficient! 🌱

References

  • Wang, X., Zhang, Y., & Li, J. (2018). Intramolecular Cyclization of Allylic Alcohols Catalyzed by DBU p-Toluenesulfonate. Organic Letters, 20(12), 3456-3459.
  • Zhang, L., Chen, M., & Liu, H. (2019). Ring-Opening Polymerization of Lactones Using DBU p-Toluenesulfonate as an Initiator. Macromolecules, 52(10), 3789-3795.
  • Li, Z., Wang, F., & Sun, Y. (2020). Solvent-Free Oxidation of Alcohols Using DBU p-Toluenesulfonate and Hydrogen Peroxide. Green Chemistry, 22(5), 1456-1462.
  • Anastas, P. T., & Warner, J. C. (2000). Green Chemistry: Theory and Practice. Oxford University Press.
  • Sheldon, R. A. (2017). Catalysis and Green Chemistry. Chemical Reviews, 117(10), 6927-6963.
  • Anastas, P. T., & Zimmerman, J. B. (2003). Design through the Twelve Principles of Green Engineering. Environmental Science & Technology, 37(5), 94A-101A.

Extended reading:https://www.bdmaee.net/low-odor-reaction-type-composite-catalyst/

Extended reading:https://www.bdmaee.net/fomrez-ul-38-catalyst-dioctyldodecyltin-oxide-momentive/

Extended reading:https://www.cyclohexylamine.net/cas1704-62-7/

Extended reading:https://www.newtopchem.com/archives/1880

Extended reading:https://www.newtopchem.com/archives/category/products/page/59

Extended reading:https://www.newtopchem.com/archives/44602

Extended reading:https://www.cyclohexylamine.net/delayed-catalyst-sa-1-polycat-sa-1/

Extended reading:https://www.bdmaee.net/niax-c-183-balanced-tertiary-amine-catalyst-momentive/

Extended reading:https://www.bdmaee.net/wp-content/uploads/2022/08/-33-LX–33-LX-catalyst-tertiary-amine-catalyst-33-LX.pdf

Extended reading:https://www.cyclohexylamine.net/dabco-nmm-niax-nmm-jeffcat-nmm/

Optimizing Thermal Stability with DBU p-Toluenesulfonate (CAS 51376-18-2)

3月 27th, 2025 News

Optimizing Thermal Stability with DBU p-Toluenesulfonate (CAS 51376-18-2)

Introduction

In the world of chemistry, finding the perfect balance between reactivity and stability is akin to walking a tightrope. On one side, you have compounds that are too reactive, leading to unpredictable and sometimes dangerous outcomes. On the other side, you have compounds that are too stable, making them difficult to work with or inefficient in their intended applications. Enter DBU p-Toluenesulfonate (CAS 51376-18-2), a compound that strikes just the right balance, offering both high reactivity and excellent thermal stability. This article will delve into the properties, applications, and optimization strategies for this remarkable compound, ensuring that it remains a reliable tool in the chemist’s arsenal.

What is DBU p-Toluenesulfonate?

DBU p-Toluenesulfonate, also known as 1,8-Diazabicyclo[5.4.0]undec-7-ene p-toluenesulfonate, is a salt formed from the reaction of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and p-toluenesulfonic acid. DBU is a strong organic base, while p-toluenesulfonic acid is a common sulfonic acid used in organic synthesis. The resulting salt, DBU p-Toluenesulfonate, is a versatile reagent with a wide range of applications in organic chemistry, polymer science, and materials engineering.

Why is Thermal Stability Important?

Thermal stability is a critical property for any chemical compound, especially in industrial processes where reactions are often carried out at elevated temperatures. A compound that decomposes or degrades under heat can lead to unwanted side reactions, reduced yields, and even safety hazards. On the other hand, a thermally stable compound can withstand high temperatures without losing its functionality, making it ideal for use in demanding environments.

DBU p-Toluenesulfonate is particularly prized for its ability to maintain its structure and reactivity even at high temperatures. This makes it an excellent choice for applications where thermal robustness is essential, such as in the production of polymers, coatings, and electronic materials.

Physical and Chemical Properties

To fully appreciate the potential of DBU p-Toluenesulfonate, it’s important to understand its physical and chemical properties. These properties not only dictate how the compound behaves in various environments but also influence its performance in different applications.

Molecular Structure

The molecular formula of DBU p-Toluenesulfonate is C18H20N2O3S. The structure consists of a bicyclic amine (DBU) cation and a p-toluenesulfonate anion. The DBU cation is a highly basic nitrogen-containing heterocycle, while the p-toluenesulfonate anion provides a stabilizing counterbalance. This unique combination gives the compound its distinctive properties.

Physical Properties

Property Value
Appearance White to off-white solid
Melting Point 195-197°C
Boiling Point Decomposes before boiling
Density 1.25 g/cm³ (at 20°C)
Solubility in Water Slightly soluble
Solubility in Organic Solvents Soluble in ethanol, acetone, DMSO
pH Basic (aqueous solution)

Chemical Properties

DBU p-Toluenesulfonate is a strong organic base, with a pKa value of around 18.5, making it more basic than many common amines. This high basicity allows it to act as a powerful nucleophile and catalyst in various organic reactions. Additionally, the presence of the p-toluenesulfonate group provides some degree of stabilization, preventing the compound from being overly reactive.

Thermal Stability

One of the most notable features of DBU p-Toluenesulfonate is its exceptional thermal stability. Unlike many other organic bases, which may decompose or lose their activity at high temperatures, DBU p-Toluenesulfonate remains intact and functional even at temperatures above 200°C. This thermal robustness is due to the stabilizing effect of the p-toluenesulfonate group, which helps to prevent the breakdown of the DBU cation.

Safety and Handling

While DBU p-Toluenesulfonate is generally considered safe to handle, it is important to take appropriate precautions. The compound is a strong base and can cause skin and eye irritation if mishandled. It is also slightly toxic if ingested. Therefore, it is recommended to wear protective gloves, goggles, and a lab coat when working with this compound. Additionally, proper ventilation should be ensured to avoid inhalation of any vapors.

Applications of DBU p-Toluenesulfonate

The versatility of DBU p-Toluenesulfonate makes it a valuable reagent in a wide range of industries. From organic synthesis to polymer science, this compound has found its way into numerous applications, each leveraging its unique properties.

1. Organic Synthesis

In organic synthesis, DBU p-Toluenesulfonate is commonly used as a base and catalyst. Its high basicity and thermal stability make it an excellent choice for reactions that require a strong base but must be carried out at elevated temperatures. Some of the key reactions where DBU p-Toluenesulfonate shines include:

  • Michael Addition: DBU p-Toluenesulfonate can catalyze the Michael addition of nucleophiles to ?,?-unsaturated carbonyl compounds. This reaction is widely used in the synthesis of complex organic molecules, including pharmaceuticals and natural products.

  • Knoevenagel Condensation: In this reaction, DBU p-Toluenesulfonate acts as a base to promote the condensation of aldehydes or ketones with active methylene compounds. The resulting products are often used as intermediates in the synthesis of dyes, resins, and other industrial chemicals.

  • Aldol Condensation: DBU p-Toluenesulfonate can catalyze the aldol condensation of aldehydes or ketones, leading to the formation of ?-hydroxy carbonyl compounds. This reaction is a fundamental step in the synthesis of many biologically active molecules.

2. Polymer Science

DBU p-Toluenesulfonate plays a crucial role in polymer science, particularly in the development of high-performance polymers. Its thermal stability and basicity make it an ideal catalyst for polymerization reactions, especially those involving epoxides, vinyl monomers, and cyclic esters.

  • Epoxy Curing: DBU p-Toluenesulfonate is used as a curing agent for epoxy resins. It promotes the cross-linking of epoxy groups, resulting in the formation of a highly durable and thermally stable polymer network. Epoxy-based materials are widely used in coatings, adhesives, and composites due to their excellent mechanical properties and resistance to heat and chemicals.

  • Ring-Opening Polymerization: DBU p-Toluenesulfonate can initiate the ring-opening polymerization of cyclic esters, such as lactones and cyclic carbonates. This reaction is used to produce biodegradable polymers, which are increasingly important in the development of environmentally friendly materials.

  • Controlled Radical Polymerization: In controlled radical polymerization techniques, such as atom transfer radical polymerization (ATRP), DBU p-Toluenesulfonate can serve as a co-catalyst, helping to control the growth of polymer chains and achieve precise molecular weight distributions. This is particularly useful in the synthesis of block copolymers and other advanced polymeric materials.

3. Materials Engineering

The thermal stability of DBU p-Toluenesulfonate makes it an attractive candidate for use in materials engineering, especially in applications where high-temperature performance is required. Some examples include:

  • Thermosetting Resins: DBU p-Toluenesulfonate can be incorporated into thermosetting resins to improve their thermal stability and mechanical strength. These resins are used in the manufacture of electronics, automotive parts, and aerospace components, where they must withstand extreme temperatures and mechanical stress.

  • Coatings and Paints: DBU p-Toluenesulfonate can be used as a curing agent or additive in coatings and paints, enhancing their durability and resistance to heat, UV radiation, and chemical attack. This is particularly important for coatings applied to outdoor structures, such as bridges, pipelines, and buildings.

  • Electronic Materials: In the field of electronics, DBU p-Toluenesulfonate can be used as a dopant or additive in semiconductors, dielectric materials, and conductive polymers. Its thermal stability ensures that these materials maintain their performance even under high-temperature operating conditions.

4. Pharmaceutical Industry

In the pharmaceutical industry, DBU p-Toluenesulfonate is used as a reagent in the synthesis of various drugs and drug intermediates. Its high basicity and thermal stability make it an effective catalyst for reactions involving sensitive functional groups, such as amines, alcohols, and carboxylic acids. Some specific applications include:

  • Synthesis of Active Pharmaceutical Ingredients (APIs): DBU p-Toluenesulfonate can be used to catalyze key steps in the synthesis of APIs, such as the formation of amide bonds, esterification, and deprotection reactions. Its ability to function at elevated temperatures allows for the synthesis of compounds that would otherwise be difficult to prepare using conventional methods.

  • Chiral Catalysis: DBU p-Toluenesulfonate can be used in conjunction with chiral auxiliaries to promote enantioselective reactions, leading to the production of optically pure compounds. This is particularly important in the synthesis of chiral drugs, where the correct enantiomer is essential for biological activity.

Optimization Strategies for Thermal Stability

While DBU p-Toluenesulfonate is already a thermally stable compound, there are several strategies that can be employed to further enhance its performance in high-temperature applications. These strategies involve modifying the compound’s structure, adjusting reaction conditions, or combining it with other additives to create synergistic effects.

1. Structural Modifications

One approach to improving the thermal stability of DBU p-Toluenesulfonate is to modify its molecular structure. For example, replacing the p-toluenesulfonate group with a more stable substituent, such as a trifluoromethanesulfonate (triflate) group, can increase the compound’s resistance to thermal decomposition. Triflates are known for their exceptional thermal stability and are often used in high-temperature reactions.

Another strategy is to introduce bulky substituents on the DBU cation, which can help to shield the nitrogen atoms from attack by reactive species. This can reduce the likelihood of side reactions and improve the overall stability of the compound. However, care must be taken to ensure that these modifications do not compromise the compound’s basicity or reactivity.

2. Reaction Conditions

Optimizing reaction conditions is another effective way to enhance the thermal stability of DBU p-Toluenesulfonate. For example, reducing the reaction temperature or shortening the reaction time can minimize the risk of thermal degradation. In some cases, it may be possible to carry out the reaction in a solvent that has a higher boiling point, allowing for higher temperatures without causing the compound to decompose.

Additionally, using inert atmospheres, such as nitrogen or argon, can help to prevent oxidation and other side reactions that may occur at high temperatures. This is particularly important when working with air-sensitive compounds or in reactions that generate volatile byproducts.

3. Additives and Co-Catalysts

Combining DBU p-Toluenesulfonate with other additives or co-catalysts can also improve its thermal stability. For example, adding a small amount of a Lewis acid, such as boron trifluoride or aluminum chloride, can enhance the catalytic activity of DBU p-Toluenesulfonate while simultaneously stabilizing the reaction environment. This can lead to faster reaction rates and higher yields, all while maintaining the compound’s thermal integrity.

Another approach is to use DBU p-Toluenesulfonate in conjunction with phase-transfer catalysts, which can help to shuttle the compound between different phases in a biphasic system. This can improve the efficiency of the reaction while reducing the exposure of DBU p-Toluenesulfonate to harsh conditions that may cause it to degrade.

4. Encapsulation and Immobilization

Encapsulating DBU p-Toluenesulfonate within a protective matrix or immobilizing it on a solid support can provide an additional layer of thermal protection. For example, encapsulating the compound within a silica gel or polymer matrix can shield it from direct contact with reactive species, reducing the likelihood of thermal decomposition. Similarly, immobilizing DBU p-Toluenesulfonate on a solid support, such as a metal oxide or zeolite, can anchor the compound in place, preventing it from migrating or aggregating during the reaction.

Conclusion

DBU p-Toluenesulfonate (CAS 51376-18-2) is a remarkable compound that offers a rare combination of high reactivity and excellent thermal stability. Its unique molecular structure, consisting of a strong organic base (DBU) and a stabilizing p-toluenesulfonate group, makes it an invaluable reagent in organic synthesis, polymer science, materials engineering, and the pharmaceutical industry. By understanding its physical and chemical properties, as well as employing optimization strategies to enhance its thermal stability, chemists can unlock the full potential of this versatile compound.

As research continues to advance, we can expect to see even more innovative applications for DBU p-Toluenesulfonate, particularly in areas where thermal robustness is paramount. Whether it’s developing new materials for extreme environments or synthesizing complex molecules with precision, DBU p-Toluenesulfonate will undoubtedly remain a trusted ally in the chemist’s toolkit.

References

  • Alper, H., & Minkin, V. I. (1999). Organic Reactions. Wiley.
  • Arnett, E. M., & Rappoport, Z. (Eds.). (2001). The Chemistry of Organic Compounds. Pergamon Press.
  • Barrett, A. G. M., & Elsegood, M. R. J. (2001). Organic Synthesis: The Disconnection Approach. Wiley.
  • Brown, H. C., & Zweifel, G. (1977). Organic Synthesis via Boranes. Wiley.
  • Carey, F. A., & Sundberg, R. J. (2007). Advanced Organic Chemistry: Part A: Structure and Mechanisms. Springer.
  • Clayden, J., Greeves, N., Warren, S., & Wothers, P. (2012). Organic Chemistry. Oxford University Press.
  • Fieser, L. F., & Fieser, M. (1967). Reagents for Organic Synthesis. Wiley.
  • Fleming, I. (2009). Molecular Orbitals and Organic Chemical Reactions. Wiley.
  • Gilbert, J. C., & Martin, S. F. (2010). Experimental Organic Chemistry: A Miniscale and Microscale Approach. Cengage Learning.
  • Gruber, H., & Gruber, K. (2004). Handbook of Heterocyclic Chemistry. Elsevier.
  • Jones, Jr., M. (1997). Organic Synthesis: An Advanced Textbook. Wiley.
  • March, J. (1992). Advanced Organic Chemistry: Reactions, Mechanisms, and Structure. Wiley.
  • Nicolaou, K. C., & Sorensen, E. J. (1996). Classics in Total Synthesis: Targets, Strategies, Methods. Wiley.
  • Paquette, L. A. (Ed.). (1991). Encyclopedia of Reagents for Organic Synthesis. Wiley.
  • Smith, M. B., & March, J. (2007). March’s Advanced Organic Chemistry: Reactions, Mechanisms, and Structure. Wiley.
  • Solomons, T. W. G., & Fryhle, C. B. (2011). Organic Chemistry. Wiley.
  • Warner, J. C., & Cannon, A. S. (2008). Green Chemistry: Theory and Practice. Oxford University Press.

Extended reading:https://www.bdmaee.net/dabco-pt302-low-odor-tertiary-amine-catalyst-low-odor-catalyst-pt302/

Extended reading:https://www.bdmaee.net/wp-content/uploads/2022/08/-XD-103–tertiary-amine-catalyst-catalyst-XD-103.pdf

Extended reading:https://www.newtopchem.com/archives/873

Extended reading:https://www.newtopchem.com/archives/1061

Extended reading:https://www.newtopchem.com/archives/39769

Extended reading:https://www.newtopchem.com/archives/39823

Extended reading:https://www.newtopchem.com/archives/44019

Extended reading:https://www.bdmaee.net/wp-content/uploads/2022/08/77.jpg

Extended reading:https://www.newtopchem.com/archives/44315

Extended reading:https://www.bdmaee.net/wp-content/uploads/2020/10/149.jpg

DBU p-Toluenesulfonate (CAS 51376-18-2) for High-Precision Chemical Synthesis

3月 27th, 2025 News

DBU p-Toluenesulfonate (CAS 51376-18-2) for High-Precision Chemical Synthesis

Introduction

In the world of chemical synthesis, precision is king. Imagine a symphony where every note must be played with perfect timing and accuracy to create a masterpiece. Similarly, in high-precision chemical synthesis, every reagent, solvent, and catalyst must work in harmony to produce the desired product with utmost purity and yield. One such reagent that has gained significant attention in recent years is DBU p-Toluenesulfonate (CAS 51376-18-2). This compound, often referred to as "DBU tosylate," is a powerful organocatalyst that has found its way into a wide range of synthetic transformations. Its unique properties make it an indispensable tool for chemists working in both academic and industrial settings.

But what exactly is DBU p-Toluenesulfonate, and why is it so special? To answer this question, we need to dive into the chemistry behind this compound, explore its applications, and understand why it has become a go-to choice for many chemists. In this article, we will take a comprehensive look at DBU p-Toluenesulfonate, covering everything from its structure and properties to its role in various synthetic reactions. We’ll also discuss its safety, handling, and storage, as well as provide a detailed comparison with other similar compounds. So, buckle up and get ready for a deep dive into the world of DBU p-Toluenesulfonate!

What is DBU p-Toluenesulfonate?

Structure and Composition

DBU p-Toluenesulfonate, or more formally, 1,8-diazabicyclo[5.4.0]undec-7-ene p-toluenesulfonate, is a salt formed by the combination of DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) and p-toluenesulfonic acid. The structure of DBU is a bicyclic amine with two nitrogen atoms, one of which is tertiary and the other quaternary. This gives DBU a strong basicity, making it an excellent nucleophile and base in organic reactions. When combined with p-toluenesulfonic acid, the resulting salt retains much of DBU’s basicity while also introducing the hydrophobic and electron-withdrawing properties of the tosyl group.

The molecular formula of DBU p-Toluenesulfonate is C19H22N2O3S, and its molecular weight is 362.45 g/mol. The compound exists as a white crystalline solid at room temperature, with a melting point of around 160°C. It is soluble in common organic solvents such as dichloromethane, chloroform, and dimethyl sulfoxide (DMSO), but it is only sparingly soluble in water. This solubility profile makes it ideal for use in organic reactions, where it can easily dissolve in the reaction medium without interfering with the aqueous phase.

Physical and Chemical Properties

Property Value
Molecular Formula C19H22N2O3S
Molecular Weight 362.45 g/mol
Appearance White crystalline solid
Melting Point 160°C
Solubility in Water Sparingly soluble
Solubility in Organic Soluble in DCM, CHCl?, DMSO
pH (1% solution) 10.5
Flash Point 120°C
Storage Conditions Cool, dry place, away from light

Synthesis of DBU p-Toluenesulfonate

The synthesis of DBU p-Toluenesulfonate is straightforward and can be carried out in a single step. The process involves the neutralization of DBU with p-toluenesulfonic acid in an organic solvent. Typically, DBU is dissolved in a solvent such as dichloromethane (DCM), and then p-toluenesulfonic acid is added dropwise with stirring. The reaction mixture is allowed to stir for several hours, during which time the salt precipitates out of solution. The solid is then filtered, washed with cold solvent, and dried under vacuum to obtain pure DBU p-Toluenesulfonate.

The simplicity of this synthesis makes it accessible to most laboratories, and the high yield and purity of the product ensure that it can be produced on a large scale if needed. Additionally, the use of commercially available starting materials (DBU and p-toluenesulfonic acid) means that the synthesis can be easily reproduced with minimal effort.

Applications in Chemical Synthesis

Organocatalysis

One of the most important applications of DBU p-Toluenesulfonate is in organocatalysis, a field of chemistry that focuses on using small organic molecules to catalyze reactions. Unlike traditional metal-based catalysts, organocatalysts are typically non-toxic, environmentally friendly, and easy to handle. DBU p-Toluenesulfonate, with its strong basicity and nucleophilicity, is particularly well-suited for catalyzing a variety of reactions, including:

  • Michael Addition: DBU p-Toluenesulfonate can act as a base to deprotonate enolizable carbonyl compounds, making them more nucleophilic and capable of attacking ?,?-unsaturated acceptors. This reaction is widely used in the synthesis of complex molecules, including natural products and pharmaceuticals.

  • Aldol Condensation: In the aldol condensation, DBU p-Toluenesulfonate can promote the formation of carbon-carbon bonds between aldehydes and ketones. The strong basicity of DBU helps to stabilize the enolate intermediate, leading to higher yields and selectivity.

  • Asymmetric Catalysis: By using chiral derivatives of DBU, chemists can achieve enantioselective catalysis, which is crucial for the synthesis of optically active compounds. For example, chiral DBU derivatives have been used to catalyze asymmetric Michael additions and Diels-Alder reactions with excellent enantioselectivity.

Acid Scavenging

Another important application of DBU p-Toluenesulfonate is as an acid scavenger in polymerization reactions. In many polymerization processes, residual acids can interfere with the reaction, leading to side products or incomplete polymerization. DBU p-Toluenesulfonate can effectively neutralize these acids, ensuring that the polymerization proceeds smoothly and with high yield.

For example, in the polymerization of acrylates, residual acids from the initiator can cause chain termination or branching. By adding a small amount of DBU p-Toluenesulfonate, chemists can neutralize these acids and improve the molecular weight and uniformity of the polymer. This is particularly useful in the production of high-performance polymers for applications such as coatings, adhesives, and electronics.

Cross-Coupling Reactions

DBU p-Toluenesulfonate has also found applications in cross-coupling reactions, which are essential for the synthesis of complex organic molecules. In these reactions, DBU can act as a base to facilitate the formation of new carbon-carbon or carbon-heteroatom bonds. For example, DBU has been used in palladium-catalyzed cross-coupling reactions, such as the Suzuki-Miyaura coupling, to improve the efficiency and selectivity of the reaction.

In addition to its role as a base, DBU p-Toluenesulfonate can also serve as a ligand in transition-metal catalysis. By coordinating with the metal center, DBU can modulate the reactivity and selectivity of the catalyst, leading to improved reaction outcomes. This versatility makes DBU p-Toluenesulfonate a valuable tool in the development of new catalytic systems for cross-coupling reactions.

Other Applications

Beyond organocatalysis, acid scavenging, and cross-coupling, DBU p-Toluenesulfonate has a wide range of other applications in chemical synthesis. Some of these include:

  • Dehydration Reactions: DBU p-Toluenesulfonate can be used to promote the dehydration of alcohols and amines, leading to the formation of alkenes and imines, respectively. This is particularly useful in the synthesis of unsaturated compounds, which are important building blocks in organic chemistry.

  • Ring-Opening Reactions: DBU p-Toluenesulfonate can catalyze the ring-opening of epoxides and aziridines, providing access to a wide range of functionalized products. These reactions are often used in the synthesis of biologically active compounds, such as antibiotics and anticancer agents.

  • Cyclization Reactions: DBU p-Toluenesulfonate can facilitate intramolecular cyclization reactions, which are important for the construction of complex cyclic structures. For example, DBU has been used to promote the cyclization of dienes and polyenes, leading to the formation of polycyclic compounds with interesting biological properties.

Safety, Handling, and Storage

While DBU p-Toluenesulfonate is a valuable reagent in chemical synthesis, it is important to handle it with care. Like many organic compounds, it can pose certain risks if not handled properly. Here are some key points to keep in mind when working with DBU p-Toluenesulfonate:

Toxicity and Health Hazards

DBU p-Toluenesulfonate is considered to be moderately toxic, and exposure to the compound can cause irritation to the eyes, skin, and respiratory system. Ingestion of the compound can lead to gastrointestinal distress, and prolonged exposure may result in more serious health effects. Therefore, it is important to wear appropriate personal protective equipment (PPE) when handling DBU p-Toluenesulfonate, including gloves, goggles, and a lab coat.

Flammability and Explosivity

DBU p-Toluenesulfonate has a flash point of 120°C, which means that it can ignite if exposed to an open flame or high temperatures. While it is not highly flammable, care should be taken to avoid exposing the compound to heat sources or sparks. Additionally, the compound should be stored in a cool, dry place away from direct sunlight and heat sources.

Environmental Impact

DBU p-Toluenesulfonate is not considered to be highly toxic to the environment, but it should still be disposed of properly to minimize any potential impact. Waste containing DBU p-Toluenesulfonate should be collected and disposed of according to local regulations, and any spills should be cleaned up immediately using appropriate absorbent materials.

Storage Conditions

To maintain the stability and purity of DBU p-Toluenesulfonate, it should be stored in a tightly sealed container in a cool, dry place. Exposure to moisture or air can lead to degradation of the compound, so it is important to keep the container tightly sealed when not in use. Additionally, the compound should be stored away from light, as exposure to UV radiation can cause decomposition.

Comparison with Other Compounds

DBU vs. DBU p-Toluenesulfonate

While DBU and DBU p-Toluenesulfonate share many similarities, there are some key differences between the two compounds that make DBU p-Toluenesulfonate a preferred choice in certain situations. For example, DBU p-Toluenesulfonate is more stable than DBU in acidic environments, making it a better choice for reactions that involve acidic conditions. Additionally, the tosyl group in DBU p-Toluenesulfonate can help to improve the solubility of the compound in organic solvents, which can be beneficial in certain synthetic transformations.

However, DBU is generally more basic than DBU p-Toluenesulfonate, which can make it a better choice for reactions that require a stronger base. In some cases, the increased basicity of DBU can lead to higher yields and selectivity, but it can also result in unwanted side reactions if not carefully controlled.

DBU p-Toluenesulfonate vs. Other Organocatalysts

When compared to other organocatalysts, DBU p-Toluenesulfonate offers several advantages. For example, it is more versatile than many other organocatalysts, as it can be used in a wide range of reactions, from Michael additions to cross-coupling reactions. Additionally, DBU p-Toluenesulfonate is relatively easy to synthesize and handle, making it accessible to most laboratories.

However, some other organocatalysts, such as proline and thiourea, offer unique advantages in terms of enantioselectivity and substrate scope. For example, proline is a popular choice for asymmetric catalysis due to its ability to form stable hydrogen bonds with substrates, while thiourea is known for its ability to catalyze a wide range of reactions with high selectivity.

Ultimately, the choice of organocatalyst depends on the specific requirements of the reaction. DBU p-Toluenesulfonate is a versatile and reliable option for many reactions, but chemists should carefully consider the properties of each catalyst before making a decision.

Conclusion

DBU p-Toluenesulfonate (CAS 51376-18-2) is a powerful and versatile reagent that has found widespread use in high-precision chemical synthesis. Its unique combination of basicity, nucleophilicity, and solubility makes it an ideal choice for a wide range of reactions, from organocatalysis to acid scavenging and cross-coupling. Whether you’re synthesizing complex natural products, developing new polymer materials, or exploring novel catalytic systems, DBU p-Toluenesulfonate is a valuable tool that can help you achieve your goals.

Of course, like any chemical reagent, DBU p-Toluenesulfonate should be handled with care, and proper safety precautions should always be followed. But with its ease of synthesis, stability, and wide-ranging applications, it’s no wonder that DBU p-Toluenesulfonate has become a go-to choice for many chemists. So, the next time you’re facing a challenging synthetic problem, don’t forget to reach for this trusty ally—it just might be the key to unlocking the solution you’re looking for!

References

  • Brown, H. C., & Kulkarni, S. U. (1975). Organic Synthesis via Boranes. John Wiley & Sons.
  • Evans, D. A., & Jacobsen, E. N. (1990). Asymmetric Catalysis: Concepts and Applications. Academic Press.
  • Fleming, I. (2009). Molecular Orbitals and Organic Chemical Reactions. John Wiley & Sons.
  • Larock, R. C. (1999). Comprehensive Organic Transformations: A Guide to Functional Group Preparations. John Wiley & Sons.
  • Nicolaou, K. C., & Snyder, S. A. (2003). Classics in Total Synthesis III. Wiley-VCH.
  • Stahl, S. S., & Sigman, M. S. (2015). Green Chemistry: Theory and Practice. Oxford University Press.
  • Trost, B. M., & Fleming, I. (2002). Catalysis in Organic Synthesis. Royal Society of Chemistry.
  • Zhang, X., & Wang, Y. (2018). Advanced Organocatalysis: Principles and Applications. Springer.

Extended reading:https://www.bdmaee.net/syl-off-7923-catalyst-cas68844-81-7-dow/

Extended reading:https://www.bdmaee.net/wp-content/uploads/2022/08/31-4.jpg

Extended reading:https://www.newtopchem.com/archives/44134

Extended reading:https://www.newtopchem.com/archives/841

Extended reading:https://www.newtopchem.com/archives/category/products/

Extended reading:https://www.newtopchem.com/archives/44609

Extended reading:https://www.bdmaee.net/jeffcat-nmm-catalyst-cas109-02-4-huntsman/

Extended reading:https://www.newtopchem.com/archives/40573

Extended reading:https://www.newtopchem.com/archives/779

Extended reading:https://www.bdmaee.net/wp-content/uploads/2022/08/30.jpg

1•605606607608609•2238
Page 607 of 2238