An undergraduate organic chemistry laboratory experiment is being developed and adapted from work recently published by Maity and Lepore1 investigating the cyclization of substituted �-alkynyl hydrazines to yield azaproline derivatives. The mechanism of this reaction is not fully understood but is putatively driven by a cation-p interaction of the alkynyl hydrazine with a tetrabutylammonium ion. It is our objective to design and implement a pseudo inquiry-based sophomore Organic Chemistry Lab experiment where students are presented with a cutting-edge research question to explore: what is the role of tetrabutylammonium salts in the cyclization of substituted �-alkynyl hydrazines? Students will be directed to research the conventional phase-transfer catalytic action of tetrabutylammonium salts and will then need to reconcile this information for the homogenous cyclization reaction they are studying. To help them explore this concept further (and make that connection between theory and practice), students will be guided to vary the different components of this reaction and observe the effects on kinetics and products formed. Students will probe reaction kinetics by thin-layer chromatography (TLC) and UV spectroscopy. Azaproline derivative product(s) will be purified using column chromatography and characterized by IR and NMR spectroscopy. Additionally, we are focusing on testing the most appropriate and environmentally nonhazardous �green� solvents for this reaction, including: ethyl acetate, N,N-dimethylformamide, hexane, and acetonitrile.2 Ultimately, our goal is to implement a modern research-based, cost-effective, and safe bioorganic experiment into Florida Atlantic University's undergraduate organic chemistry laboratory curriculum.1. Maity, P.; Lepore, S. D. Catalytic Synthesis of Nonracemic Azaproline Derivatives by Cyclization of �-Alkynyl Hydrazines under Kinetic Resolution Conditions. Angew. Chem. Int. Ed. 2011, 50, 8338 �8341.2. American Chemical Society Pharmaceutical Roundtable, Green Solvents, Molecular Materials Informatics, http://molsync.com/demo/greensolvents.php (accessed Oct 04, 2013).

Exploring cation-p interactions in a sophomore organic chemistry laboratory experiment

247th National Meeting (2014)

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