Cooperative learning was employed as an instructional approach to facilitate student development of spectroscopy problem solving skills. An interactive online environment was used as a framework to structure weekly discussions around spectroscopy problems outside of class. Weekly discussions consisted of modified jigsaw-style problem solving activities in which students cooperatively interpreted infrared and nuclear magnetic resonance spectra. Students' use of the discussion site was monitored and revealed that they accessed discussions in the days prior to examinations. Together with attitudinal surveys, which were used to gauge student perceptions of the activities, these results indicate that students found the discussions to be a useful resource for learning spectroscopy.

Catalytic enantioselective and diastereoselective spiroketalizations with BINOL-derived chiral phosphoric acids are reported. The chiral catalyst can override the inherent preference for the formation of thermodynamic spiroketals, and highly selective formation of nonthermodynamic spiroketals could be achieved under the reaction conditions.

Mechanistic and computational studies were conducted to elucidate the mechanism and the origins of enantiocontrol for asymmetric chiral phosphoric acid-catalyzed spiroketalization reactions. These studies were designed to differentiate between the S(N)1-like, S(N)2-like, and covalent phosphate intermediate-based mechanisms. The chiral phosphoric acid-catalyzed spiroketalization of deuterium-labeled cyclic enol ethers revealed a highly diastereoselective syn-selective protonation/nucleophile addition, thus ruling out long-lived oxocarbenium intermediates. Hammett analysis of the reaction kinetics revealed positive charge accumulation in the transition state (ρ = -2.9). A new computational reaction exploration method along with dynamics simulations supported an asynchronous concerted mechanism with a relatively short-lived polar transition state (average lifetime = 519 ± 240 fs), which is consistent with the observed inverse secondary kinetic isotope effect of 0.85. On the basis of these studies, a transition state model explaining the observed stereochemical outcome has been proposed. This model predicts the enantioselective formation of the observed enantiomer of the product with 92% ee, which matches the experimentally observed value.

General chemistry is a gateway course that impacts the STEM trajectory of tens of thousands of students each year, and its role in the introductory curriculum as well as its pedagogical design are the center of an ongoing debate. To investigate the role of general chemistry in the curriculum, we report the results of a posthoc analysis of 10 years of archived student data (ca. 12,000 students) aimed at discovering whether taking college-level general chemistry has an impact on student performance in and progression to subsequent chemistry courses. We introduce regression discontinuity; a quasi-experimental method that originated in educational psychology and can be used to estimate causal impacts of educational treatment when ex ante randomization is not feasible. Using regression discontinuity, we estimated a positive impact of prior general chemistry coursework of about one-fourth of a letter grade in two subsequent courses, Organic Chemistry I and a physical general chemistry course for nonmajors. We also found that taking general chemistry had no impact on the likelihood that students will progress to the final course in the nonmajors sequence.

An enantioselective intramolecular chiral phosphoric acid-catalyzed cyclization of unsaturated acetals has been utilized for the synthesis of functionalized chiral piperidines. The chiral enol ether products of these cyclizations undergo subsequent in situ enantioenrichment through acetalization of the minor enantiomer. A new computational reaction exploration method was utilized to elucidate the mechanism and stereoselectivity of this transformation. Rather than confirming the originally postulated cyclization proceeding directly through a vinyl oxocarbenium ion, simulations identified an alternative two-step mechanism involving the formation of a mixed chiral phosphate acetal, which undergoes a concerted, asynchronous S(N)2'-like displacement to yield the product with stereoselectivity in agreement with experimental observations.

The spiroketal functionality is an important structural motif present in numerous natural products. The synthesis of chiral spiroketals is typically achieved under equilibrating conditions and only few asymmetric approaches are known. We have demonstrated that chiral phosphoric acids (CPAs) could serve as effective catalysts for enantioselective spiroketalizations as well as control the course of the corresponding diastereoselective reactions.

An online discussion is used to engage students in data interpretation and analysis in an introductory organic chemistry laboratory course. Students post an audio or video recording to explain their problem-solving processes and to provide interpretation of laboratory data. The discussion board (VoiceThread) features a drawing tool that also supports the inclusion of images and graphical representations of data. The activities described are broadly applicable to any science discipline and are particularly useful in high-enrollment classes where opportunities for students to practice data interpretation and discussion of lab results may be limited.

An enantioselective intramolecular chiral phosphoric acid‐catalyzed cyclization of unsaturated acetals has been utilized for the synthesis of functionalized chiral piperidines. The chiral enol ether products of these cyclizations undergo subsequent in situ enantioenrichment through acetalization of the minor enantiomer. A new computational reaction exploration method was utilized to elucidate the mechanism and stereoselectivity of this transformation. Rather than confirming the originally postulated cyclization proceeding directly through a vinyl oxocarbenium ion, simulations identified an alternative two‐step mechanism involving the formation of a mixed chiral phosphate acetal, which undergoes a concerted, asynchronous SN2′‐like displacement to yield the product with stereoselectivity in agreement with experimental observations.