The Pd-catalyzed coupling of malonate nucleophiles with alkenes bearing tethered aryl or alkenyl triflates is described. These alkene difunctionalization reactions afford malonate-substituted cyclopentanes that contain fused aryl or cycloalkenyl rings. The transformations generate a fivemembered ring, two CC bonds, and provide products bearing up to three stereocenters with good chemical yield and generally high diastereoselectivity.

The introductory chemistry sequence is a common pathway for undergraduates pursuing science, technology, engineering, and math (STEM) and prehealth careers. Student's academic decision-making has far-reaching consequences for their trajectory, including persistence in the major and ultimate career choice. This phenomenon was studied using a survey and focus group interviews, which were conducted to better understand the factors that influenced student choice. Results were analyzed using exploratory factor analysis, from which personal and institutional factors were identified. Using binary logistic regression, we found that students who placed importance on institutional factors (placement test results, discussion with advisor, academic plans, course load, and confidence in preparation) were more likely to comply with their placement recommendation, whereas students who placed importance on personal factors (family and financial concerns, advice from friends and family, rumors about the course, and nonacademic obligations) were more likely to deviate from their placement recommendation. Focus group interviews were analyzed using the constant comparison method and supported the quantitative findings.

Dihalomucononitriles were synthesized and their reactivity evaluated to assess their ability to function as linchpin reagents. Bis(2-chloroacrylonitrile) and bis(2-bromoacrylonitrile) were synthesized from 2,13-benzothiadiazole and shown to undergo conjugate addition reactions with both nitrogen (40-95% yield) and carbon nucleophiles (72-93% yield). Secondary amines were found to undergo monoadditions while carbon nucleophiles added twice. The sequence of addition of the nucleophiles could be controlled giving mixed addition products. The multicomponent coupling products could then be converted to natural product-like motifs using intramolecular cyclization reactions. File list (3) download file view on ChemRxiv Zahara_Hinds_ChemRXIV_2020-FINAL.pdf (743.83 KiB) download file view on ChemRxiv Zahara Hinds SI FINAL_ ChemRXIV.pdf (1.39 MiB) download file view on ChemRxiv Zahara Hinds SI FINAL_ SPECTRA.pdf (8.63 MiB) COMMUNICATION

The synthesis of cyclic and bicyclic ureas via a ruthenium-catalyzed cross-metathesis / aza-Michael reaction strategy between protected alkenyl ureas and Michael acceptors is described. The substrates for these reactions are generated in 1-3 steps from commercially available materials, and products are formed in moderate yield with up to >20:1 diastereoselectivity.

Palladium-catalyzed alkene difunctionalization reactions between alkenes bearing tethered aryl or alkenyl triflates and enolate nucleophiles are described. The transformations form two C−C bonds, a ring, and up to two stereocenters while producing substituted cyclopentane derivatives that contain appended carbonyl functionality. Products are formed with up to >20:1 diastereoselectivity, and the formation of sterically congested bonds between quaternary carbon atoms is feasible.