This communication presents a partial historical summary of some of Iowa State University’s Chemistry Department teaching response to the shift to online course delivery caused by the COVID-19 pandemic. The observations reflect discussions between and informal surveys of an instructor cohort that impacted roughly 1200 undergraduate students. These students were enrolled in general chemistry I, organic chemistry II, inorganic chemistry, quantum mechanics, and chemistry for non-physical-science majors. The paper highlights the challenges faced and describes how faculty and students met them.

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Aspartic proteases use a pair of carboxylic acids to activate water molecules for nucleophilic attack. Here we report a nanoparticle catalyst with a similar catalytic motif capable of generating a hydroxide ion in its active site even under acidic reaction conditions. The synthetic enzyme accelerated the hydrolysis of para-nitrophenyl acetate (PNPA) by 91 000 times and could also hydrolyze nonactivated aryl esters at pH 7. The distance between the two acids and, in particular, the flexibility of the catalytic groups in the active site controlled the catalytic efficiency. The synthetic enzyme readily detected the addition of a single methyl on the acyl group of the substrate, as well as the substitution pattern on the phenyl ring.

Distinction of chemical functionality by their local chemical environment is a skill mastered by enzymes, evident from the selective synthesis, cleavage, and transformation of peptides, nucleic acids, and polysaccharides that abound with the same type of functional group. In contrast, synthetic catalysts are generally better at differentiating functional groups based on their electronic and steric properties. Here, we report artificial epoxidases prepared through the molecular imprinting of surface–core doubly cross-linked micelles, followed by efficient functionalization of the imprinted site in the micellar core via photoaffinity labeling. The size and shape of the active sites are tuned by the modularly synthesized templates, with the oxygen-delivering peroxy acid group positioned accurately. These catalysts are used in the epoxidation of alkenes in water with hydrogen peroxide under mild conditions without any additional additives. Most importantly, atomic precision is achieved in the catalysis and enables alkenes to be distinguished that differ in the position of the carbon–carbon double bond by a single carbon.

Nature has a remarkable ability to perform selective transformation of complex biological mixtures into desired products using enzymatic catalysts. We report the preparation of nanoparticle catalysts through molecular imprinting within crosslinked micelles. These catalysts were highly selective for their targeted substrates and could selectively hydrolyze less reactive acetals over more reactive ones even under basic conditions. Their catalytic activity and selectivity were tunable through rational postmodification of the active site. These properties enabled the nanoparticle catalysts to produce the desired β-nitro alcohol from a four-component acetal mixture in a tandem deprotection/Henry reaction that required incompatible acidic and basic catalysts in the two steps.