Document Type

Presentation

Publication Date

4-25-2019

Advisor

Thomas Jones, Chemistry

Abstract

Organocatalysis is the use of low molecular weight organic molecules to accelerate chemical reactions. As seen by its rapid growth over the last couple decades, this type of catalysis is attractive to synthetic chemists due to the mild reaction conditions, low cost materials and green chemistry characteristics organocatalysis offers. Thiourea-based organocatalysts promote reactions using reversible and selective, hydrogen bonding, which can be used to activate the electrophile and nucleophile reactants. By modifying the structure, co-catalysts, and other conditions used with these catalysts the activity can be modified and improved for specific products.

Using these design principles, a set of thiourea catalysts were synthesized using 3,5-bis(trifluoromethyl)phenyl isothiocyanate and either ortho and para-aminobenzoic acid, or ortho and para-aminophenol. The catalysts were screened for catalytic activity in the Henry Nitroaldol Reaction. As catalytic activity differed with structure this gave insight into optimal motifs and conditions for thiourea catalysts. These catalysts also provide a novel pairing as the thiourea functional group is paired with a carboxylic acid group instead of one of the many basic functional groups commonly paired with it. To further improve both the catalytic activity and recyclability of these catalysts while preserving their initial appealing features a silica surface could be functionalized with these thiourea catalysts.

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