Presentation Title

Organocatalytic Synthesis of Pharmaceutical Precursors

Faculty Mentor

Anna Wenzel

Start Date

23-11-2019 10:00 AM

End Date

23-11-2019 10:45 AM

Location

253

Session

poster 3

Type of Presentation

Poster

Subject Area

physical_mathematical_sciences

Abstract

Hydroamination serves as a valuable method for the preparation of pharmaceutical precursors, such as a N-heterocycles. Previous research has focused on achieving hydroamination using lanthanide-metal catalysts, early transition metal catalysts, and copper catalysts. However, with the growing endangerment of these metals, our laboratory is focused on developing sustainable methods of achieving hydroamination through the use of organocatalysts.

Our laboratory has thus far explored the organocatalyzed, Markovnikov hydroamination of two olefins using either ammonium trifluoroacetate salts or thioacetic acids as the reaction catalysts to produce dihydroquinolines and dihydrobenzo-oxazines, respectively. Preliminary work suggests that organocatalysts structurally resembling ammonium trifluoroacetate are more suitable for reactions with allyl ether substrates. These conclusions were drawn after monitoring the conversion of reactant to product by gas chromatography, during which the allyl ether substrate showed a 90% conversion to product using ammonium trifluoroacetate salt and a 50% conversion to product using thioacetic acid within the first 24 hours.

Our research has additionally found that allene-containing substrates, which can be highly reactive to produce pyrrolidine products, require protecting groups capable of providing an ideal balance between substrate reactivity vs. decomposition. When using a benzyl protecting group, allene-containing substrates are highly reactive and begin to form the hydroamination product without the aid of an added catalyst. Our future work with this substrate aims to attach a protecting group, such as benzyl carbamate (Cbz), that would decrease the overall reactivity of the substrate and increase its stability.

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Nov 23rd, 10:00 AM Nov 23rd, 10:45 AM

Organocatalytic Synthesis of Pharmaceutical Precursors

253

Hydroamination serves as a valuable method for the preparation of pharmaceutical precursors, such as a N-heterocycles. Previous research has focused on achieving hydroamination using lanthanide-metal catalysts, early transition metal catalysts, and copper catalysts. However, with the growing endangerment of these metals, our laboratory is focused on developing sustainable methods of achieving hydroamination through the use of organocatalysts.

Our laboratory has thus far explored the organocatalyzed, Markovnikov hydroamination of two olefins using either ammonium trifluoroacetate salts or thioacetic acids as the reaction catalysts to produce dihydroquinolines and dihydrobenzo-oxazines, respectively. Preliminary work suggests that organocatalysts structurally resembling ammonium trifluoroacetate are more suitable for reactions with allyl ether substrates. These conclusions were drawn after monitoring the conversion of reactant to product by gas chromatography, during which the allyl ether substrate showed a 90% conversion to product using ammonium trifluoroacetate salt and a 50% conversion to product using thioacetic acid within the first 24 hours.

Our research has additionally found that allene-containing substrates, which can be highly reactive to produce pyrrolidine products, require protecting groups capable of providing an ideal balance between substrate reactivity vs. decomposition. When using a benzyl protecting group, allene-containing substrates are highly reactive and begin to form the hydroamination product without the aid of an added catalyst. Our future work with this substrate aims to attach a protecting group, such as benzyl carbamate (Cbz), that would decrease the overall reactivity of the substrate and increase its stability.