Undergraduate Organic Chemistry Laboratory Research Articles

Merging Inline NMR Monitoring and Flow Chemistry in the Undergraduate Organic Chemistry Laboratory

Merging Inline NMR Monitoring and Flow Chemistry in the Undergraduate Organic Chemistry Laboratory

Incorporating Green Chemistry into Undergraduate Organic Chemistry Laboratory: Synthesis of Banana Oil

Incorporating Green Chemistry into Undergraduate Organic Chemistry Laboratory: Synthesis of Banana Oil

Improving Undergraduate Organic Chemistry Laboratories through Integration with Research: Prospects and a Model Study

Improving Undergraduate Organic Chemistry Laboratories through Integration with Research: Prospects and a Model Study

A Comprehensive Inquiry-Based Comparative Experiment for an Undergraduate Organic Chemistry Laboratory Course: Elucidating the Formation Process of N-Phenylbenzamide

A Comprehensive Inquiry-Based Comparative Experiment for an Undergraduate Organic Chemistry Laboratory Course: Elucidating the Formation Process of <i>N</i>-Phenylbenzamide

Correction to “Crossed Aldol Reactions in Water Using Inexpensive and Easily Available Materials as a Tool for Reaction Optimization Teaching in an Undergraduate Organic Chemistry Laboratory”

Correction to “Crossed Aldol Reactions in Water Using Inexpensive and Easily Available Materials as a Tool for Reaction Optimization Teaching in an Undergraduate Organic Chemistry Laboratory”

A safe-at-home benzoin condensation from imitation almond extract

Abstract COVID-19 remote learning forced instructors to scramble for meaningful organic laboratory experiences safe enough to perform at home. While resources are available for laboratory experiments at home, organic synthesis suffers from issues involving safety, availabilities of reagents, difficulties measuring reagents, and difficulties analyzing products. We report a new take on the classic benzoin condensation using safe and commonly available reagents, capable of being setup with commonly available kitchen materials, and displaying visible and distinctive product. This experiment is aimed at reinforcing concepts of carbonyl chemistry in the undergraduate organic chemistry laboratory.

Microwave-Assisted Extraction of Trimyristin from Nutmeg using Ethanol: A Greener Approach for the Undergraduate Organic Chemistry Laboratory

Microwave-Assisted Extraction of Trimyristin from Nutmeg using Ethanol: A Greener Approach for the Undergraduate Organic Chemistry Laboratory

Copper(I)-Catalyzed Kinugasa Reactions in an Undergraduate Organic Chemistry Laboratory

A β-lactam, the core structure unit of clinically important antibiotics such as penicillin and cephalosporin, is one of the most commonly encountered four-membered heterocycles in organic chemistry and is widely used in medicine and biochemistry. The Kinugasa reaction, a copper(I)-catalyzed cycloaddition of a terminal alkyne with a nitrone, is a straightforward and atom economic approach to 2,3-disubstituted β-lactams. This paper describes a comprehensive chemistry experiment involving the Kinugasa reaction in an advanced undergraduate organic chemistry laboratory course. Undergraduate students perform the Kinugasa reaction on the benchtop and isolate and characterize the β-lactam product. An understanding of this named reaction and the connection of organic chemistry with medicinal chemistry are specially emphasized in the class. Several modern chemistry concepts that are missing from traditional organic courses such as β-lactam chemistry, [3 + 2] cycloaddition, atom economy, and the important role of transition metal catalysis in organic reactions are introduced to students in this course.

Gas Chromatography–Mass Spectrometry Analysis of Cannabis: Undergraduate Organic Chemistry Laboratory Exercise

In this laboratory teaching experiment, commercial cannabis oils were analyzed by undergraduate organic chemistry students using gas chromatography–mass spectrometry (GC–MS) to investigate three isomeric cannabinoids commonly found in cannabis products: cannabidiol (CBD), Δ9-tetrahydrocannabinol (Δ9-THC), and Δ8-tetrahydrocannabinol (Δ8-THC). The goal was to introduce GC–MS analysis through the relevant topic of product quality inspection, frequently used in various industries such as pharmaceuticals, cosmetics, etc. and which largely involves analyzing the chemical components of a sample. First, to better understand the cannabinoid analytes, students were taught the differences between these structural isomers, including bond locations, stereochemistry, and functional groups─factors which pertain to their pharmacology and drug classification. Finally, students were guided through the basics of GC–MS instrumentation and the process of analyzing GC–MS spectra through the characterization of CBD, Δ8-THC, and Δ9-THC present in oil samples.

A Thin Layer Chromatography Prelaboratory Activity Using a 3D-Printed Model to Address Student Misconceptions about Polarity and Intermolecular Forces

Normal phase thin layer chromatography is a widely taught technique in undergraduate organic chemistry laboratory courses. To understand how the technique works, students must have a strong conceptual understanding of polarity and intermolecular forces. Unfortunately, many students have misconceptions regarding how polarity and intermolecular forces affect the separation of compounds via thin layer chromatography. This work aimed to address these misconceptions by designing and implementing a prelaboratory activity using a 3D-printed model of a TLC plate. Data from pre- and postactivity surveys suggest the activity has a positive impact on student understanding, and student perceptions of the activity are overwhelmingly positive.

An Efficient Undergraduate Synthesis of the Exorbitantly Priced Lambert–Eaton Myasthenic Syndrome Drug Amifampridine

An efficient synthesis of the exorbitantly priced Lambert–Eaton myasthenic syndrome drug amifampridine was developed and applied in the second-semester undergraduate organic chemistry laboratory. The two-step synthesis entails a nucleophilic aromatic substitution reaction of commercial 4-chloro-3-nitropyridine with methanolic ammonia to afford 4-amino-3-nitropyridine. Subsequent palladium-catalyzed nitro reduction provides amifampridine in high yield and purity. Amifampridine can alternatively be prepared by advanced undergraduate students in four linear steps beginning with 4-hydroxypyridine. Nitration of 4-hydroxypyridine to 4-hydroxy-3-nitropyridine and subsequent treatment with phosphoryl chloride provides the intermediate 4-chloro-3-nitropyridine, which is then subjected to the SNAr and reduction reactions to cleanly afford amifampridine without the need for column chromatography.

Updating the Benzoin Condensation of Benzaldehyde Using Microwave-Assisted Organic Synthesis and N-Heterocyclic Carbene Catalysis

The benzoin condensation of benzaldehyde is a staple of the undergraduate organic chemistry laboratory, introducing the current topic of nucleophilic carbene organocatalysis. Our procedure makes notable improvements to current practice, including the elimination of solvent waste and an 18-fold reduction of reaction time. We have demonstrated that microwave heating provides yields comparable to current practice in 5 min, using significantly less power (70 W) than traditional heating methods. The highest yields were obtained with N,N′-(2,4,6-trimethylphenyl)imidazolium chloride (IMes·HCl) as the catalyst and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as the base. Our procedure has been successfully executed by multiple cohorts of organic chemistry undergraduates, both with and without pandemic social distancing constraints.

Cultivating Student Research Interests in Undergraduate Organic Chemistry Lab Course through Class Activity

Undergraduate organic chemistry laboratory courses act as a baseline for introductory scientific experimentation. These courses provide students with the knowledge and skills for their future careers. The traditional lab is conducted by providing a structured protocol of the experiment for the students to follow and reproduce the assigned task while collecting data and making observations when prompted. Though this confirmation-style approach is effective at imparting skills, it fails to demonstrate the true nature of scientific experimentation, which is discovery and problem-solving. To this end, we have redesigned the organic chemistry laboratory courses by using a “research-esque” discovery-style learning, in which certain experiments are treated as a research project. During the lab, reaction parameters within the experiment were varied by the students to compare their results with their peers, so as to create an opportunity to increase the understanding of the experiment at hand, pique the students’ interests in the subject, and create an environment that is similar to scientific research by redesigning the lab protocols. Some case studies are provided herein as samples of our pedagogical improvement.

Reformed Experimental Activities (REActivities): Gauging the Fidelity of Implementation in a Reformed Undergraduate Organic Chemistry Laboratory.

Reformed Experimental Activities (REActivities) is an innovative approach to the delivery of the traditional material in an undergraduate organic chemistry laboratory. To better understand the fidelity of implementing this pedagogy and what effects the framework of REActivities has on student-instructor interactions, an observational protocol study was employed. This paper also describes the Evaluation of Lab Instructor Time and Engagement (ELITE) observational instrument developed to evaluate instructional behaviors in a lab setting. The instrument was used in first semester undergraduate organic chemistry laboratories across seven universities to measure the robustness of the guided-inquiry materials when implemented and the nature of the instructor's interactions. The ELITE data was analyzed for laboratories delivered using REActivities and compared with expert delivery as well as with traditional expository methods. The data revealed that instructor behaviors when using REActivities were consistent and comparable and could be distinguished from traditional lab deliveries. The nature of the instructor's behaviors also showed a remarkably consistent trend for coded conceptual-based discussion when REActivities was employed, in contrast to the near absence of similar interactions when expository methods were employed for comparable laboratories.

New Look at the Competitive Nucleophilic Substitution Reaction in the Pentanol Series

Substitution reactions of alcohols are some of the simplest experiments performed in undergraduate organic chemistry laboratory settings. However, the use of gas chromatography (GC) as an analytical tool for these reactions can be at times laborious and time-consuming. In this work, 1-pentanol, 2-pentanol, 3-pentanol, and 2-methyl-2-butanol were reacted with a 50/50 mixture of ammonium chloride–ammonium bromide in water to yield the corresponding alkyl bromide and alkyl chloride mixtures. Aliquots of the reaction mixture were analyzed using proton nuclear magnetic resonance (1H NMR) spectroscopy and verified by GC. Secondary to secondary carbocation rearrangements were observed in the nucleophilic substitution reactions of 2- and 3-pentanol yielding a mixture of 2- and 3-substituted alkyl halides, while the primary and tertiary alcohols yielded the expected products. Students were assessed on their observations and explanations with the majority of them able to identify the correct reasoning for the alkyl halides mixture formation. 1H NMR spectroscopy provided an inexpensive and quicker method to analyze the mixture and expose the students to the secondary to secondary carbocation rearrangement in the nucleophilic substitution reaction in the pentanol series.

Ethynylated Acene Synthesis and Photophysics for an Organic Chemistry Laboratory Course

An operationally simple, reliable synthesis of ethynylated acenes suitable for an upper-division undergraduate organic chemistry laboratory course has been developed. This experiment requires students to synthesize two acene derivatives and can be completed in 6–8 laboratory sessions (3 h each); a shorter experiment could be realized in the synthesis of only one product. Synthesis is carried out by first treating a terminal alkyne with n-butyllithium in an oven-dried flask under nitrogen at 0 °C. An acene quinone is added, which produces a doubly ethynylated diol. Dehydration with SnCl2/HCl yields a bis(ethynylated) acene, which is purified via a short pad or column of silica gel. The intense colors of the products allow for great ease in determining reaction completion and following the products in chromatography. UV–vis and fluorescence spectroscopy may be used to better understand the effect of molecular structure on electronic properties.

Crossed Aldol Reactions in Water Using Inexpensive and Easily Available Materials as a Tool for Reaction Optimization Teaching in an Undergraduate Organic Chemistry Laboratory

We present an experiment designed to hone the decision-making skills of (undergraduate) chemistry students by using aqueous crossed aldol reactions. Here, we present two simple crossed aldol reacti...

Green Hydrogenation: Solvent-Free Hydrogenation of Pinenes for An Undergraduate Organic Chemistry Laboratory

Reorienting organic chemistry laboratories with an emphasis on systemic thinking can only be beneficial to students. Addressing the challenges of climate change and the development of renewable resources with a fundamental reaction, such as the hydrogenation of an alkene, will allow students to see organic chemistry as a science beneficial to society. For this purpose, a green organic laboratory experiment in which students performed solvent-free catalytic hydrogenation of β- or α-pinene was developed. Using a homemade high- or low-pressure autoclave, solvent-free hydrogenation of β- or α-pinene over Pd/C produced a mixture of cis- and trans-pinanes. The monitoring of the reaction by NMR, IR, and GC-MS allowed the students to be familiar with the isomerization of an alkene and the shift of an equilibrium according to Le Chatelier’s principle. The filtration of the catalyst near the halftime of reaction and the continuation of the hydrogenation off catalyst allowed the students to confirm the heterogeneous nature of the hydrogenation.

Development of a Large-Enrollment Course-Based Research Experience in an Undergraduate Organic Chemistry Laboratory: Structure–Function Relationships in Pyrylium Photoredox Catalysts

Despite the recognized effectiveness of course-based undergraduate research experiences (CUREs), there are few examples of the development of a CURE-based course in a large-enrollment undergraduate...

Environmentally Friendly Organic Chemistry Laboratory Experiments for the Undergraduate Curriculum: A Literature Survey and Assessment

Due to a growing awareness of environmental issues, green chemistry concepts are increasingly being incorporated into the undergraduate organic chemistry lecture and laboratory component. This minireview summarizes environmentally friendly organic chemistry experiments suitable for undergraduate laboratories. Whenever feasible, LD50 values for various chemicals are provided to allow readers to determine the suitability of an experiment for their curriculum based on the toxicity of reagents used.