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.

Organocatalytic enantioselective α-hydroxymethylation of aldehydes: mechanistic aspects and optimization.

Further studies of the direct enantioselective α-hydroxymethylation of aldehydes employing the α,α-diarylprolinol trimethylsilyl ether class of organocatalysts are described. This process has proven efficient for access to ß-hydroxycarboxylic acids and δ-hydroxy-α,ß-unsaturated esters from aldehydes in generally good yields, excellent enantioselectivity, and compatibility with a broad range of functional groups in the aldehyde. The goal of these studies was to identify the critical reaction variables that influence the yield and enantioselectivity of the α-hydroxymethylation process such as catalyst structure, pH of the medium, purity of the reactants and reagents particularly with respect to the presence of acidic impurities, and the nature of the buffer, along with the standard variables including solvent, time, temperature and mixing efficiency. The previously identified intermediate lactol has been further characterized and its reactivity examined. These studies have led to identification of the most critical variables translating directly into improved substrate scope, reproducibility, enantioselectivity, and yields.