Introduction of a simple experiment for the undergraduate organic chemistry laboratory demonstrating the Lewis acid and shape-selective properties of zeolite Na-Y

A simple, inexpensive, discovery-based experiment for undergraduate organic laboratories has been developed that demonstrates the Lewis acid and shape-selective properties of zeolites. Calcined zeolite Na-Y promotes the electrophilic aromatic bromination of toluene with a significantly higher para/ortho ratio than observed under conventional conditions. The experiment can be completed in one three-hour laboratory period. The zeolite can be recovered and regenerated for later reuse. A broad range of organic course topics from orientation in electrophilic aromatic substitution to photochemistry can be discussed

Enabling Technologies for the Future of Chemical Synthesis.

Technology is evolving at breakneck pace, changing the way we communicate, travel, find out information, and live our lives. Yet chemistry as a science has been slower to adapt to this rapidly shifting world. In this Outlook we use highlights from recent literature reports to describe how progresses in enabling technologies are altering this trend, permitting chemists to incorporate new advances into their work at all levels of the chemistry development cycle. We discuss the benefits and challenges that have arisen, impacts on academic-industry relationships, and future trends in the area of chemical synthesis.We are grateful to the Woolf Fisher Trust (D.E.F), Syngenta Crop Protection AG (C.B.) and EPSRC (S.V.L., grant codes EP/K009494/1, EP/M004120/1 and EP/K039520/1) for financial assistance.This is the final version of the article. It first appeared from the American Chemical Society via https://doi.org/10.1021/acscentsci.6b0001

The dark side of biomass valorization: A laboratory experiment to understand humins formation, catalysis and green chemistry

This laboratory experiment introduces students to an important reaction in biomass valorization and allows them to gain a practical understanding of green chemistry. Acid-catalyzed dehydration reactions of fructose to 5-hydroxymethylfurfural and thus humins were performed both with and without aqueous solvent, along with two different catalysts (Amberlyst-15 and alumina). Students were able to compare and analyze the effects of these different conditions using thin-layer chromatography, while grasping concepts of catalysis and circular economy. By observing the formation of humins under some of the reactions tested, the students could evidence systems thinking in humin valorization

Continuous Processing and Efficient in Situ\textit{in Situ} Reaction Monitoring of a Hypervalent Iodine(III) Mediated Cyclopropanation Using Benchtop NMR Spectroscopy

Real-time NMR spectroscopy has proven to be a rapid and an effective monitoring tool to study the hypervalent iodine(III) mediated cyclopropanation. With the ever increasing number of new synthetic methods for carbon−carbon bond formation, the NMR $\textit{in situ}$ monitoring of reactions is becoming a highly desirable enabling method. In this study, we have demonstrated the versatility of benchtop NMR using inline and online real-time monitoring methods to access mutually complementary information for process understanding, and we developed new approaches for real-time monitoring addressing challenges associated with better integration into continuous processes.University of Cambridge (Daphne Jackson Fellowship), iCON through CMAC (Grant ID: RG74817), Engineering and Physical Sciences Research Council (Critical Mass grant (Grant ID: EP/K009494K/1), Core Capability grant (Grant ID: EP/K039520/1

What is hindering change? Anticipating the barriers to the adoption of enzyme-based textile processing in a developing country

The study aimed to examine the barriers to embracing enzymatic processing in the garment industry in a developing country. We used the case of Bangladesh, which has the largest garment sector in the world. The research used semi-structured interviews with ten high profile figures in the industry, comprising scientists, manufacturers, enzyme traders and policymakers. We found economic, sociocultural, informational and policy-related barriers to the adoption of enzymatic processing. Attending to each element would benefit manufacturers primarily; this will help identify its strengths and weaknesses to ensure the effective implementation of enzymatic textile processing to obtain optimum results. The study also found that manufacturers’ desire to help improve environmental performance is a factor which could motivate them in adopting green manufacturing innovation. It is expected that regulatory frameworks that encourage innovation - particularly from high social responsiveness and compliances as well as economic and financial incentives - would motivate manufacturers to develop sustainable environmental management strategies that enhance their ability to compete in global markets

Scope and Mechanistic Study of the Coupling Reaction of α,β-Unsaturated Carbonyl Compounds with Alkenes: Uncovering Electronic Effects on Alkene Insertion vs Oxidative Coupling Pathways

The cationic ruthenium-hydride complex [(C6H6)(PCy3)(CO)RuH]+BF4– (1) was found to be a highly effective catalyst for the intermolecular conjugate addition of simple alkenes to α,β-unsaturated carbonyl compounds to give (Z)-selective tetrasubstituted olefin products. The analogous coupling reaction of cinnamides with electron-deficient olefins led to the oxidative coupling of two olefinic C–H bonds in forming (E)-selective diene products. The intramolecular version of the coupling reaction efficiently produced indene and bicyclic fulvene derivatives. The empirical rate law for the coupling reaction of ethyl cinnamate with propene was determined as follows: rate = k[1]1[propene]0[cinnamate]−1. A negligible deuterium kinetic isotope effect (kH/kD = 1.1 ± 0.1) was measured from both (E)-C6H5CH═C(CH3)CONHCH3 and (E)-C6H5CD═C(CH3)CONHCH3 with styrene. In contrast, a significant normal isotope effect (kH/kD = 1.7 ± 0.1) was observed from the reaction of (E)-C6H5CH═C(CH3)CONHCH3 with styrene and styrene-d8. A pronounced carbon isotope effect was measured from the coupling reaction of (E)-C6H5CH═CHCO2Et with propene (13C(recovered)/13C(virgin) at Cβ = 1.019(6)), while a negligible carbon isotope effect (13C(recovered)/13C(virgin) at Cβ = 0.999(4)) was obtained from the reaction of (E)-C6H5CH═C(CH3)CONHCH3 with styrene. Hammett plots from the correlation of para-substituted p-X-C6H4CH═CHCO2Et (X = OCH3, CH3, H, F, Cl, CO2Me, CF3) with propene and from the treatment of (E)-C6H5CH═CHCO2Et with a series of para-substituted styrenes p-Y-C6H4CH═CH2 (Y = OCH3, CH3, H, F, Cl, CF3) gave the positive slopes for both cases (ρ = +1.1 ± 0.1 and +1.5 ± 0.1, respectively). Eyring analysis of the coupling reaction led to the thermodynamic parameters, ΔH⧧ = 20 ± 2 kcal mol–1 and ΔS⧧ = −42 ± 5 eu. Two separate mechanistic pathways for the coupling reaction have been proposed on the basis of these kinetic and spectroscopic studies

An environmentally benign antimicrobial nanoparticle based on a silver-infused lignin core

Silver nanoparticles have antibacterial properties, but their use has been a cause for concern because they persist in the environment. Here, we show that lignin nanoparticles infused with silver ions and coated with a cationic polyelectrolyte layer form a biodegradable and green alternative to silver nanoparticles. The polyelectrolyte layer promotes the adhesion of the particles to bacterial cell membranes and, together with silver ions, can kill a broad spectrum of bacteria, including Escherichia coli, Pseudomonas aeruginosa and quaternary-amine-resistant Ralstonia sp. Ion depletion studies have shown that the bioactivity of these nanoparticles is time-limited because of the desorption of silver ions. High-throughput bioactivity screening did not reveal increased toxicity of the particles when compared to an equivalent mass of metallic silver nanoparticles or silver nitrate solution. Our results demonstrate that the application of green chemistry principles may allow the synthesis of nanoparticles with biodegradable cores that have higher antimicrobial activity and smaller environmental impact than metallic silver nanoparticles